Holy goabs of torque batman!!!! And less pinging too!!!!
02-12-08, 01:28 PM
#61
Lexus Champion
lol you're probably right. but damn when they were new didn't they get 60 in 7.3 or so? i've never seen a car lose so much power over time if we're all 9+ now...
02-12-08, 01:36 PM
#62
Pole Position
Join Date: Jan 2007
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1990 Lexus LS 400 8.1 16.1
1992 Lexus LS 400 8.0 16.0
1993 Lexus LS 400 8.2 16.2
1995 Lexus LS 400 7.4 15.5
1998 Lexus LS 400 6.3 14.8
2001 Lexus LS 430 6.7 14.8
http://www.albeedigital.com/supercou...0-60times.html
1992 Lexus LS 400 8.0 16.0
1993 Lexus LS 400 8.2 16.2
1995 Lexus LS 400 7.4 15.5
1998 Lexus LS 400 6.3 14.8
2001 Lexus LS 430 6.7 14.8
http://www.albeedigital.com/supercou...0-60times.html
02-12-08, 01:38 PM
#63
which was optomistic to the max
http://www.lexus.com/contact/pdf/1991/1991LSspecs.pdf
93 - 7.9__15.8
96 - 7.1__15.3
98 - 6.4__14.9
02-12-08, 03:42 PM
#64
Lexus Test Driver
0-60 on these things may not be hot but when you're cruising on the highway and a 92 Accord full of mexicans won't leave you alone. (personal experience)
these things FLY!!!!! I got from 60-110mph so quick! I wasn't even really expecting to go that fast
First time I really opened my car up on the highway 
these things FLY!!!!! I got from 60-110mph so quick! I wasn't even really expecting to go that fast
First time I really opened my car up on the highway
02-12-08, 03:54 PM
#65
This is frustrating,.. and you are sinking money left and right into the car. In my opinion you've put so much into this engine/car that it is pretty much a principle thing now. No turning back. (You could cut your losses, but you've narrowed it down)
You have tried so many things that things have become cloudy now.. sort of a scatter brained arena now.
Which is why you should take all these *great* suggestions and just go down the list one by one.
From your description:
I would tend to think the timing on the car is being toyed with by your ECU (computer).
Have you Checked the timing? If so, is it in spec? This isn't hard to do, and would be a good indicator of what your ECU is telling your engine to do. (Lower timing it senses some problems and is backing things down (lowering power essentially) to protect itself.
Your ECU is not throwing CEL's.. So , yes, if your engine is running amuck and the CEL's are not being displayed, then a funky ECU is suspect. Thing is, of course, a new ECU is far from cheap. Though obtaining one from a junked Lexus wouldn't be so bad, and at worst it would confirm or deny an ECU problem, at best it would fix the problem. (The swap isn't that difficult).
I won't add much more to this, other than to say you have gotten amazing feedback on what to try -- and do let us know what you find out. Since you are sinking so much money into this already. You are frustrated. Why not go ahead and bring it to the most reputable Lexus dealership in your area and tell them what is going on, and instruct them to diagnose the problem.
They will figure it out one way or another, and you will have at most a diagnostic fee of 50-100$. If you allow them to fix it (all going to depend on the cost of course) -- they usually waive the Dx fee.
Though in this case I would be willing to pay the experts up to 100$ to figure out just what the heck the problem is. I would make sure though, that before you let them have it, that unless they find the problem there will be no charge.
IE: You don't want them to diagnose it and charge you for a 'we think it might be either one of 8 different things) You want , obviously, it narrowed down to the specific solution.
Lastly,: About 0-60 Times in these cars.
Yes, new, the LS400's of any Generation is under 8 seconds. However 0-60 times are always reported very different from different sources. Then there is ones own measurement, which is generally slower due to the 'driver' and method of timing. (Also in older/higher milage vehicles you can expect a loss of power) -- However! If your LS400 of any year is taking over 10 seconds from 0-60 you have somewhat of a problem. That is a signficant loss of power. Though, again, it isn't easy to accurately measure a 0-60 time with a stopwatch while driving etc. You would need a track, or a least a speed computer that measures G's/0-60/quarter and so on based on Gyro sensors etc.
Even the Gen I LS400's , if kept in good condition mechanically, should be running no (timed accurately) no more than 9 seconds 0-60. The car should not be losing that much power even with 100-200k well maintained. (There are so many variables in this that it is hard to judge though) -- These cars are not meant for 'drag' or racing,.. so alot of people have relatively healthy engines that the ECU or other factors have caused a percentage of Rear wheel horsepower loss yet the car still rides smooth and has plenty of power left over. I believe the Gen I came with 260-265 HP? If you lose 30HP over time, you still have plenty left over for the car to feel responsive and drive well.
Good luck on your evasive problem/solution!
You have tried so many things that things have become cloudy now.. sort of a scatter brained arena now.
Which is why you should take all these *great* suggestions and just go down the list one by one.
From your description:
I would tend to think the timing on the car is being toyed with by your ECU (computer).
Have you Checked the timing? If so, is it in spec? This isn't hard to do, and would be a good indicator of what your ECU is telling your engine to do. (Lower timing it senses some problems and is backing things down (lowering power essentially) to protect itself.
Your ECU is not throwing CEL's.. So , yes, if your engine is running amuck and the CEL's are not being displayed, then a funky ECU is suspect. Thing is, of course, a new ECU is far from cheap. Though obtaining one from a junked Lexus wouldn't be so bad, and at worst it would confirm or deny an ECU problem, at best it would fix the problem. (The swap isn't that difficult).
I won't add much more to this, other than to say you have gotten amazing feedback on what to try -- and do let us know what you find out. Since you are sinking so much money into this already. You are frustrated. Why not go ahead and bring it to the most reputable Lexus dealership in your area and tell them what is going on, and instruct them to diagnose the problem.
They will figure it out one way or another, and you will have at most a diagnostic fee of 50-100$. If you allow them to fix it (all going to depend on the cost of course) -- they usually waive the Dx fee.
Though in this case I would be willing to pay the experts up to 100$ to figure out just what the heck the problem is. I would make sure though, that before you let them have it, that unless they find the problem there will be no charge.
IE: You don't want them to diagnose it and charge you for a 'we think it might be either one of 8 different things)
You want , obviously, it narrowed down to the specific solution.Lastly,: About 0-60 Times in these cars.
Yes, new, the LS400's of any Generation is under 8 seconds. However 0-60 times are always reported very different from different sources. Then there is ones own measurement, which is generally slower due to the 'driver' and method of timing. (Also in older/higher milage vehicles you can expect a loss of power) -- However! If your LS400 of any year is taking over 10 seconds from 0-60 you have somewhat of a problem. That is a signficant loss of power. Though, again, it isn't easy to accurately measure a 0-60 time with a stopwatch while driving etc. You would need a track, or a least a speed computer that measures G's/0-60/quarter and so on based on Gyro sensors etc.
Even the Gen I LS400's , if kept in good condition mechanically, should be running no (timed accurately) no more than 9 seconds 0-60. The car should not be losing that much power even with 100-200k well maintained. (There are so many variables in this that it is hard to judge though) -- These cars are not meant for 'drag' or racing,.. so alot of people have relatively healthy engines that the ECU or other factors have caused a percentage of Rear wheel horsepower loss yet the car still rides smooth and has plenty of power left over. I believe the Gen I came with 260-265 HP? If you lose 30HP over time, you still have plenty left over for the car to feel responsive and drive well.
Good luck on your evasive problem/solution!
02-12-08, 06:38 PM
#66
Well, I have two cars, a GS430 and LS400, and these cars have a very similar engine, with almost identical block, but different heads/cams, both have pretty restricted intake and exaust. But there's just a world of difference how they accelerate, the GS is a beast and the LS feels like a geo metro packed with 5 passengers.
I've pretty much narrowed the problem. The car is running lean, to little fuel is being sent to the engine by the ECU, therefore the car already loses power, but too make matters worse, the car starts misfiring because of low air/fuel ratio, knock sensors pick that up and the ECU retards timing as much as it can, making the cars acceleration pathetic.
What I didn't know however, is what is causing the ECU to make the air/fuel ratio so lean. It could've been the MAF, O2 sensors, temp sensor and TPS sensor - and I've replaced them all.
Misfiring could also be contributed to bad ignition, so I maintained that with new spark plugs, wires, rotors, caps, ignition coil and timing belt. I also replaced the thermostat and water pump, and flushed the coolant to make sure that the coolant system is top notch.
It could also be the fuel delivery system - fuel pump, fuel filter, fuel rails and fuel injectors. The only thing I've replaced so far is the fuel filter, and ran a few cleaners through the gas tank, including SeaFoam, BG44K and Chevron. But I'm confident that it's not the fuel delivery system, because the car runs so well with MAF disconnected.
I also did much good to the intake system by cleaning the throttle body, adjusting throttle cable, running SeaFoam in the intake manifold, and cleaning the PCV Valve. I also prevented PS fluid from leaking into the manifold by bypassing the PS Air control valve.
Given all that maintenance, the car should've regained any power it's lost due to age. It defenately regained the smoothness - idles and cruises beautifly, never bucks, but the power is gone. It's basically narrowed down that the ECU is at fault. And the old posts by SC300T confirm that. However, I'm not sure whether the ECU is bad due to bad programming from the factory, or because it's physically bad (leaking capacitors, etc). If I was to get a brand new ECU or a rebuilt one, would the problem go away and for how long.
Right now I'm confident that pretty much all of the first gen LS and SC, 90-94, do not perform like they should. Most of their owners either dont realize it because they think that Lexus isn't suposed to be fast, or because they think their car is old, or because they simply don't drive their cars hard. It is more evident between SC400 guys, a lot of them seem to be concerned with the low performance of their cars, but then again a lot of them blame it on the fact that it's a Lexus and wasn't suposed to be sporty. Plus, there aren't many SC400's, most SC's are 300, so their voices are lost. If you search these and SC400 forums for "hesitation", "MAF", "acceleration" you will have find quite a few discussions with members concerned about how slow their V8's are, but no definitive solution.
But now since I've narrowed it down to the ECU, there are a few ways for me to deal with it;
1) Get a brand new ECU from the dealership. The question is however, how long is it going to last? If it lasts 5+ years, then it might be worth it. Also, are they available brand new from the dealership or are they rebuilt units?
2) Get the ECU rebuilt - there are many companies that rebuild ECU's. However if it's the programming that is bad, then rebuilding the ECU won't help.
3) Get a piggyback air/fuel controller such as SAFC, and get the car properly dyno tuned. However, my concern with that is - if the stock ECU is progressively cutting the air/fuel ratio as the car ages, that means that I will have to progressively re-tune the SAFC. The other concern of couse is if the ECU is cutting the A/F based on the O2 input, then anything I tune with SAFC is a waste of time, because the ECU will cut the fuel based on the O2 input to achieve the wrong air/fuel ratio that is incorrectly programmed into it.
4) Get an ECU from a junkyard, but what are the chances of it being good? Junkyard purchases are non refundable, and I don't need another bad ECU.
5) Get a standalone air/fuel computer, not a piggyback. But those are very costly, and I don't know if the car is worth it. I'm most likely going to get another car in the summer/fall, and I don't know what I'm going to do with the LS once I do that. But I'm stubborn and still want to get to the bottom of the problem.
I've pretty much narrowed the problem. The car is running lean, to little fuel is being sent to the engine by the ECU, therefore the car already loses power, but too make matters worse, the car starts misfiring because of low air/fuel ratio, knock sensors pick that up and the ECU retards timing as much as it can, making the cars acceleration pathetic.
What I didn't know however, is what is causing the ECU to make the air/fuel ratio so lean. It could've been the MAF, O2 sensors, temp sensor and TPS sensor - and I've replaced them all.
Misfiring could also be contributed to bad ignition, so I maintained that with new spark plugs, wires, rotors, caps, ignition coil and timing belt. I also replaced the thermostat and water pump, and flushed the coolant to make sure that the coolant system is top notch.
It could also be the fuel delivery system - fuel pump, fuel filter, fuel rails and fuel injectors. The only thing I've replaced so far is the fuel filter, and ran a few cleaners through the gas tank, including SeaFoam, BG44K and Chevron. But I'm confident that it's not the fuel delivery system, because the car runs so well with MAF disconnected.
I also did much good to the intake system by cleaning the throttle body, adjusting throttle cable, running SeaFoam in the intake manifold, and cleaning the PCV Valve. I also prevented PS fluid from leaking into the manifold by bypassing the PS Air control valve.
Given all that maintenance, the car should've regained any power it's lost due to age. It defenately regained the smoothness - idles and cruises beautifly, never bucks, but the power is gone. It's basically narrowed down that the ECU is at fault. And the old posts by SC300T confirm that. However, I'm not sure whether the ECU is bad due to bad programming from the factory, or because it's physically bad (leaking capacitors, etc). If I was to get a brand new ECU or a rebuilt one, would the problem go away and for how long.
Right now I'm confident that pretty much all of the first gen LS and SC, 90-94, do not perform like they should. Most of their owners either dont realize it because they think that Lexus isn't suposed to be fast, or because they think their car is old, or because they simply don't drive their cars hard. It is more evident between SC400 guys, a lot of them seem to be concerned with the low performance of their cars, but then again a lot of them blame it on the fact that it's a Lexus and wasn't suposed to be sporty. Plus, there aren't many SC400's, most SC's are 300, so their voices are lost. If you search these and SC400 forums for "hesitation", "MAF", "acceleration" you will have find quite a few discussions with members concerned about how slow their V8's are, but no definitive solution.
But now since I've narrowed it down to the ECU, there are a few ways for me to deal with it;
1) Get a brand new ECU from the dealership. The question is however, how long is it going to last? If it lasts 5+ years, then it might be worth it. Also, are they available brand new from the dealership or are they rebuilt units?
2) Get the ECU rebuilt - there are many companies that rebuild ECU's. However if it's the programming that is bad, then rebuilding the ECU won't help.
3) Get a piggyback air/fuel controller such as SAFC, and get the car properly dyno tuned. However, my concern with that is - if the stock ECU is progressively cutting the air/fuel ratio as the car ages, that means that I will have to progressively re-tune the SAFC. The other concern of couse is if the ECU is cutting the A/F based on the O2 input, then anything I tune with SAFC is a waste of time, because the ECU will cut the fuel based on the O2 input to achieve the wrong air/fuel ratio that is incorrectly programmed into it.
4) Get an ECU from a junkyard, but what are the chances of it being good? Junkyard purchases are non refundable, and I don't need another bad ECU.
5) Get a standalone air/fuel computer, not a piggyback. But those are very costly, and I don't know if the car is worth it. I'm most likely going to get another car in the summer/fall, and I don't know what I'm going to do with the LS once I do that. But I'm stubborn and still want to get to the bottom of the problem.
This is frustrating,.. and you are sinking money left and right into the car. In my opinion you've put so much into this engine/car that it is pretty much a principle thing now. No turning back. (You could cut your losses, but you've narrowed it down)
You have tried so many things that things have become cloudy now.. sort of a scatter brained arena now.
Which is why you should take all these *great* suggestions and just go down the list one by one.
From your description:
I would tend to think the timing on the car is being toyed with by your ECU (computer).
Have you Checked the timing? If so, is it in spec? This isn't hard to do, and would be a good indicator of what your ECU is telling your engine to do. (Lower timing it senses some problems and is backing things down (lowering power essentially) to protect itself.
Your ECU is not throwing CEL's.. So , yes, if your engine is running amuck and the CEL's are not being displayed, then a funky ECU is suspect. Thing is, of course, a new ECU is far from cheap. Though obtaining one from a junked Lexus wouldn't be so bad, and at worst it would confirm or deny an ECU problem, at best it would fix the problem. (The swap isn't that difficult).
I won't add much more to this, other than to say you have gotten amazing feedback on what to try -- and do let us know what you find out. Since you are sinking so much money into this already. You are frustrated. Why not go ahead and bring it to the most reputable Lexus dealership in your area and tell them what is going on, and instruct them to diagnose the problem.
They will figure it out one way or another, and you will have at most a diagnostic fee of 50-100$. If you allow them to fix it (all going to depend on the cost of course) -- they usually waive the Dx fee.
Though in this case I would be willing to pay the experts up to 100$ to figure out just what the heck the problem is. I would make sure though, that before you let them have it, that unless they find the problem there will be no charge.
IE: You don't want them to diagnose it and charge you for a 'we think it might be either one of 8 different things) You want , obviously, it narrowed down to the specific solution.
Lastly,: About 0-60 Times in these cars.
Yes, new, the LS400's of any Generation is under 8 seconds. However 0-60 times are always reported very different from different sources. Then there is ones own measurement, which is generally slower due to the 'driver' and method of timing. (Also in older/higher milage vehicles you can expect a loss of power) -- However! If your LS400 of any year is taking over 10 seconds from 0-60 you have somewhat of a problem. That is a signficant loss of power. Though, again, it isn't easy to accurately measure a 0-60 time with a stopwatch while driving etc. You would need a track, or a least a speed computer that measures G's/0-60/quarter and so on based on Gyro sensors etc.
Even the Gen I LS400's , if kept in good condition mechanically, should be running no (timed accurately) no more than 9 seconds 0-60. The car should not be losing that much power even with 100-200k well maintained. (There are so many variables in this that it is hard to judge though) -- These cars are not meant for 'drag' or racing,.. so alot of people have relatively healthy engines that the ECU or other factors have caused a percentage of Rear wheel horsepower loss yet the car still rides smooth and has plenty of power left over. I believe the Gen I came with 260-265 HP? If you lose 30HP over time, you still have plenty left over for the car to feel responsive and drive well.
Good luck on your evasive problem/solution!
You have tried so many things that things have become cloudy now.. sort of a scatter brained arena now.
Which is why you should take all these *great* suggestions and just go down the list one by one.
From your description:
I would tend to think the timing on the car is being toyed with by your ECU (computer).
Have you Checked the timing? If so, is it in spec? This isn't hard to do, and would be a good indicator of what your ECU is telling your engine to do. (Lower timing it senses some problems and is backing things down (lowering power essentially) to protect itself.
Your ECU is not throwing CEL's.. So , yes, if your engine is running amuck and the CEL's are not being displayed, then a funky ECU is suspect. Thing is, of course, a new ECU is far from cheap. Though obtaining one from a junked Lexus wouldn't be so bad, and at worst it would confirm or deny an ECU problem, at best it would fix the problem. (The swap isn't that difficult).
I won't add much more to this, other than to say you have gotten amazing feedback on what to try -- and do let us know what you find out. Since you are sinking so much money into this already. You are frustrated. Why not go ahead and bring it to the most reputable Lexus dealership in your area and tell them what is going on, and instruct them to diagnose the problem.
They will figure it out one way or another, and you will have at most a diagnostic fee of 50-100$. If you allow them to fix it (all going to depend on the cost of course) -- they usually waive the Dx fee.
Though in this case I would be willing to pay the experts up to 100$ to figure out just what the heck the problem is. I would make sure though, that before you let them have it, that unless they find the problem there will be no charge.
IE: You don't want them to diagnose it and charge you for a 'we think it might be either one of 8 different things)
You want , obviously, it narrowed down to the specific solution.Lastly,: About 0-60 Times in these cars.
Yes, new, the LS400's of any Generation is under 8 seconds. However 0-60 times are always reported very different from different sources. Then there is ones own measurement, which is generally slower due to the 'driver' and method of timing. (Also in older/higher milage vehicles you can expect a loss of power) -- However! If your LS400 of any year is taking over 10 seconds from 0-60 you have somewhat of a problem. That is a signficant loss of power. Though, again, it isn't easy to accurately measure a 0-60 time with a stopwatch while driving etc. You would need a track, or a least a speed computer that measures G's/0-60/quarter and so on based on Gyro sensors etc.
Even the Gen I LS400's , if kept in good condition mechanically, should be running no (timed accurately) no more than 9 seconds 0-60. The car should not be losing that much power even with 100-200k well maintained. (There are so many variables in this that it is hard to judge though) -- These cars are not meant for 'drag' or racing,.. so alot of people have relatively healthy engines that the ECU or other factors have caused a percentage of Rear wheel horsepower loss yet the car still rides smooth and has plenty of power left over. I believe the Gen I came with 260-265 HP? If you lose 30HP over time, you still have plenty left over for the car to feel responsive and drive well.
Good luck on your evasive problem/solution!
Last edited by Och; 02-12-08 at 06:45 PM.
02-12-08, 08:23 PM
#68
Just real quick -- I think you are dead on in your assumptions. However the ECU's aren't on the 'list' of things that go bad with the LS400's. So I would assume buying one from a junkyard would be fine. They aren't a problematic 'wear and tear' problem with this car. So I would say odds that a junkyard LS's ECU being 'good' would be 95-99%. (As long as it didn't get hit in the impact , etc).
I wouldn't buy a new one , and I wouldn't get the programming redone. I would definitely call around to half a dozen or a dozen junk yards and find the cheapest ECU you could for your make.
If that doesn't work, I think it could almost certainly rule out the ECU .. and I might seriously entertain the idea of letting Lexus just find the problem and tell you what is up. =)
Though, would that be breaking the unwritten law of self-diagnosing? hehe..
I wouldn't buy a new one , and I wouldn't get the programming redone. I would definitely call around to half a dozen or a dozen junk yards and find the cheapest ECU you could for your make.
If that doesn't work, I think it could almost certainly rule out the ECU .. and I might seriously entertain the idea of letting Lexus just find the problem and tell you what is up. =)
Though, would that be breaking the unwritten law of self-diagnosing? hehe..
02-12-08, 08:35 PM
#69
Just real quick -- I think you are dead on in your assumptions. However the ECU's aren't on the 'list' of things that go bad with the LS400's. So I would assume buying one from a junkyard would be fine. They aren't a problematic 'wear and tear' problem with this car. So I would say odds that a junkyard LS's ECU being 'good' would be 95-99%. (As long as it didn't get hit in the impact , etc).
I wouldn't buy a new one , and I wouldn't get the programming redone. I would definitely call around to half a dozen or a dozen junk yards and find the cheapest ECU you could for your make.
If that doesn't work, I think it could almost certainly rule out the ECU .. and I might seriously entertain the idea of letting Lexus just find the problem and tell you what is up. =)
Though, would that be breaking the unwritten law of self-diagnosing? hehe..
I wouldn't buy a new one , and I wouldn't get the programming redone. I would definitely call around to half a dozen or a dozen junk yards and find the cheapest ECU you could for your make.
If that doesn't work, I think it could almost certainly rule out the ECU .. and I might seriously entertain the idea of letting Lexus just find the problem and tell you what is up. =)
Though, would that be breaking the unwritten law of self-diagnosing? hehe..
Well, the ECU's do not go bad completely, like in some cases when you're not even able to start the car, never mind worrying about air/fuel ratios, but I believe there's something wrong with a lot of first gen ECU's. I'll keep researching that, and eventually I'll solve the problem... although the solution might be another car.
Last edited by Och; 02-13-08 at 04:24 PM.
02-12-08, 10:11 PM
#70
ok so after reading like all 5 pages of that. i have the same problem with the whole, if u just liek lightly on the pedal like driving through a parking lot kine, it'll like hesitate and sound like it's working and then itt like jolts into 2nd gear. so far i thinking i guess i should replace the MAF and the fuel pump? i think? i was getting very lost. >_< sry.
o and i'm a sc400 owner.
peace out
o and i'm a sc400 owner.
peace out
02-13-08, 04:56 AM
#72
Lexus Champion
1990 Lexus LS 400 8.1 16.1
1992 Lexus LS 400 8.0 16.0
1993 Lexus LS 400 8.2 16.2
1995 Lexus LS 400 7.4 15.5
1998 Lexus LS 400 6.3 14.8
2001 Lexus LS 430 6.7 14.8
http://www.albeedigital.com/supercou...0-60times.html
1992 Lexus LS 400 8.0 16.0
1993 Lexus LS 400 8.2 16.2
1995 Lexus LS 400 7.4 15.5
1998 Lexus LS 400 6.3 14.8
2001 Lexus LS 430 6.7 14.8
http://www.albeedigital.com/supercou...0-60times.html
well back in (89-94) they were OEM-LISTED at 7.9.......
which was optomistic to the max
http://www.lexus.com/contact/pdf/1991/1991LSspecs.pdf
93 - 7.9__15.8
96 - 7.1__15.3
98 - 6.4__14.9
which was optomistic to the max
http://www.lexus.com/contact/pdf/1991/1991LSspecs.pdf
93 - 7.9__15.8
96 - 7.1__15.3
98 - 6.4__14.9
interesting stats. i guess i was a bit optimistic! lol...
oh well, i didnt buy it to be fast; low and slow is my motto.
i'd love to swap ina 98-00 engine though one day, seems like the best bang for the buck.
anyway, back on topic, sorry to stray.
02-13-08, 05:02 AM
#73
Lexus Test Driver
Well, as many of you read in my previous treads, I purchased a 94 LS400 with nearly 100k on the clock in July. The car has three problems: rough idle and stalling which I fixed by cleaning throttle body; pinging at midrange RPMs and lack of power. In an attempt to resolve the last two problems I replaced the fuel filter, air filter, cleaned out PCV valve, used various inject cleaners and octane boosters, did a full seafoam treatment (oil, crackcase, and intake). Did a full tune up including new spark plugs, wires, distributor caps and rotors. All to no avail.
Well today it stuck me... what if.... And I proceeded to remove my ECU fuse, unplugging the MAF sensor, and reinstalling the ECU fuse. Needless to say the check engine light is on, traction controll is off, BUT the car now has goabs, and I mean literally goabs of power. Step on the gas halfway from a dead stop, it kicks you back in the seat, chirps tires and pulls like a V8 should!!! On top of that, the pings are now rare, and occur rather random, more at part throttle than at full throttle. They are also very distinctive, loud pings, compared to the pinging I have with the MAF connected, which sound like a rattle.
So I conclude that my MAF sensor has come to the end of its life. Even though its not completely dead, it's lying to the ECU about the amout of air coming into the engine, most likely reporting too little air, so the ECU isn't supplying enough fuel, therefore I get what most likely to be a lean condition, thus no power and pings. With the MAF disconnected I guess the ECU is supplying excessive fuel, therefore the car is probably running rich, thus the random pings. However the engine is making a lot of power.
That being said, I believe most of us with a first gen LS400 are suffering the symptoms of a faulty MAF, without even knowing. And needless to say, I am EXTREMELY disappointed in Lexus for charging nearly $1,000 for a new unit. There should be no reason for this sensor to cost so much. We should file a class action lawsuit against Lexus on behalf of our CL community.
Well today it stuck me... what if.... And I proceeded to remove my ECU fuse, unplugging the MAF sensor, and reinstalling the ECU fuse. Needless to say the check engine light is on, traction controll is off, BUT the car now has goabs, and I mean literally goabs of power. Step on the gas halfway from a dead stop, it kicks you back in the seat, chirps tires and pulls like a V8 should!!! On top of that, the pings are now rare, and occur rather random, more at part throttle than at full throttle. They are also very distinctive, loud pings, compared to the pinging I have with the MAF connected, which sound like a rattle.
So I conclude that my MAF sensor has come to the end of its life. Even though its not completely dead, it's lying to the ECU about the amout of air coming into the engine, most likely reporting too little air, so the ECU isn't supplying enough fuel, therefore I get what most likely to be a lean condition, thus no power and pings. With the MAF disconnected I guess the ECU is supplying excessive fuel, therefore the car is probably running rich, thus the random pings. However the engine is making a lot of power.
That being said, I believe most of us with a first gen LS400 are suffering the symptoms of a faulty MAF, without even knowing. And needless to say, I am EXTREMELY disappointed in Lexus for charging nearly $1,000 for a new unit. There should be no reason for this sensor to cost so much. We should file a class action lawsuit against Lexus on behalf of our CL community.
02-13-08, 11:01 AM
#75
Lexus Champion
lol i thought of that right after i posted; that the high output engines probably bring a much higher premium than the early 1uz's. meh, it won't happen anyway, i'll stay low and slow and use the wrx and talon if i want to go fast.