93 LS 400 performance issues
09-01-10, 06:58 AM
#46
Stevie, I had exact the same problem with my 94 when I had it. I battled this problem, replaced nearly everything, including new MAF, did all the maintenance, EGR, you name it, and all with no cigar. You can search this forum, I had like a 20 page thread on this going on since 2006.
I no longer have the car, but it still itches my curiosity what the hell was wrong with it, and what the culprit was. If you ever resolve it, please post, I'd love to know.
When I gave up on mine, the only thing that I haven't replaced was the ECU. I did try ECU rebuilding service but that didn't help. If I was to do it all over today, I'd probably start with a brand new factory ECU.
I no longer have the car, but it still itches my curiosity what the hell was wrong with it, and what the culprit was. If you ever resolve it, please post, I'd love to know.
When I gave up on mine, the only thing that I haven't replaced was the ECU. I did try ECU rebuilding service but that didn't help. If I was to do it all over today, I'd probably start with a brand new factory ECU.
rebuilding the ecu doesnt work, at least not when ate does it. read my posts about them. they rebuilt the ecu for my 93 twice, still had issues, bought a used one from the junkyard, problem solved!
09-01-10, 07:00 AM
#47
you killed the maf by spraying cleaner in it. NEVER spray ANYTHING into the maf. this has been known on the supra forums for years and years. the electrical sensor in the housing is the same as the 7mgte in mk3 supras. all you ever need to do is wipe out the bar in the sensor with a paper towl or something. anyhow, id bet its a problem wit hthe trac tps or stepper motor, or the ecu itself.
OK Here we go HINT TO EVERYBODY - USE THE CHECK CONNECTOR IN THE ENGINE BAY, much easier to work with.
This time it made sense.
I got 3 engine codes.
24 - Intake Air tem. sensor signal
25- Air-Fuel ratio lean malfunction
31- Air Flow Meter Signal
Note all these codes appeared Aug 26th on my way home from a 4 hour drive and did not effect performance. Aug 27th I cleaned the MAF.
So I just removed the EFI 20A and cleared the codes. Air bag haa now appeared - will clear that later. Took it for a drive. Felt decent, although these symptoms vary sometimes its not bad sometimes I swear it has 90HP. Wait a few days see how it performs & if noting changes I'll do the catalytic converter check or the plugs/wires/caps rotors or ask my used parts buddy for an ECU and transmission ECU and EGR to try
This time it made sense.
I got 3 engine codes.
24 - Intake Air tem. sensor signal
25- Air-Fuel ratio lean malfunction
31- Air Flow Meter Signal
Note all these codes appeared Aug 26th on my way home from a 4 hour drive and did not effect performance. Aug 27th I cleaned the MAF.
So I just removed the EFI 20A and cleared the codes. Air bag haa now appeared - will clear that later. Took it for a drive. Felt decent, although these symptoms vary sometimes its not bad sometimes I swear it has 90HP. Wait a few days see how it performs & if noting changes I'll do the catalytic converter check or the plugs/wires/caps rotors or ask my used parts buddy for an ECU and transmission ECU and EGR to try
09-01-10, 07:21 AM
#49
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you killed the maf by spraying cleaner in it. NEVER spray ANYTHING into the maf. this has been known on the supra forums for years and years. the electrical sensor in the housing is the same as the 7mgte in mk3 supras. all you ever need to do is wipe out the bar in the sensor with a paper towl or something. anyhow, id bet its a problem wit hthe trac tps or stepper motor, or the ecu itself.
Cheers
09-01-10, 07:23 AM
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09-01-10, 07:36 AM
#51
William, looks like you purchased the same car as me on roughly the same dates. Mines a '93 LS400 gold w/tan leather. Mine worked great for 3 mths or so them started acting up which started this thread. How's yours work? Good? Wanna send me up your ECU from Florida to Nova Scotia and I'll give it a try
Cheers
Cheers
mine is gold with tan leather as well. when i bought it i knew it didn't run right. had the code 41. was hoping it was just the tps. i already had 2 extras at home. also the rack leaked out of the column input and the pasenger inner tie rod was bad. but it came with a used rack, and also a set of eibach springs. had an exhaust leak as well. i changed the rack out. found out the moron broke the studs that hold the cat to the manifold on the driver side and tried welding the cat to the manifold. had to grind that all off and torch out the studs as they wouldn't unthread, even with a 2ft pipe wrench. put bolts and nuts through. now the passenger side has a leak in the same spot, but luckily not welded, just havent had time to get it back on my friends lift.
i also need to take the reservoir off the power steering pump and flush the filter screen out. sounds like it is out of ps fluid even though its full. same thing on supras when the screen is clogged. valve covers leak, contacts in the starter are worn out, so when they show up ill change them in the starter and the valve cover gaskets at the same time. i need a trans mount, and will do the engine mounts at the same time. found the rubber part only for like $35 each for the motor mounts. still havn't installed the eibachs yet.
oh, and i had to replace the cluster as he broke the speedo needle before i bought it trying to "change the bulb" as he put it. however the front seats and center console cover were recovered in leather like a month before i bought it, so are basically brand new. i'm trying to find a mint 95+ rear seat to match for cheap(has cupholders in the rear center armrest). has an amp and 2 12's, though i want to build a box under the back dash and mod the opening for a 10in sub so ill have the entire trunk back. hopefully i can get to that soon. already got the wood etc...
all in all its a project, but since mint they go for $5-8k around here and i got it for $2300, im fine with it. just turns out it needed more work then i thought.
09-01-10, 07:48 AM
#52
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nah man, cant send you the ecu. took me awhile to find one at a reasonable price. im still fighting with ate trying to get a refund. if you were local id swap it in to test though.
mine is gold with tan leather as well. when i bought it i knew it didn't run right. had the code 41. was hoping it was just the tps. i already had 2 extras at home. also the rack leaked out of the column input and the pasenger inner tie rod was bad. but it came with a used rack, and also a set of eibach springs. had an exhaust leak as well. i changed the rack out. found out the moron broke the studs that hold the cat to the manifold on the driver side and tried welding the cat to the manifold. had to grind that all off and torch out the studs as they wouldn't unthread, even with a 2ft pipe wrench. put bolts and nuts through. now the passenger side has a leak in the same spot, but luckily not welded, just havent had time to get it back on my friends lift.
i also need to take the reservoir off the power steering pump and flush the filter screen out. sounds like it is out of ps fluid even though its full. same thing on supras when the screen is clogged. valve covers leak, contacts in the starter are worn out, so when they show up ill change them in the starter and the valve cover gaskets at the same time. i need a trans mount, and will do the engine mounts at the same time. found the rubber part only for like $35 each for the motor mounts. still havn't installed the eibachs yet.
oh, and i had to replace the cluster as he broke the speedo needle before i bought it trying to "change the bulb" as he put it. however the front seats and center console cover were recovered in leather like a month before i bought it, so are basically brand new. i'm trying to find a mint 95+ rear seat to match for cheap(has cupholders in the rear center armrest). has an amp and 2 12's, though i want to build a box under the back dash and mod the opening for a 10in sub so ill have the entire trunk back. hopefully i can get to that soon. already got the wood etc...
all in all its a project, but since mint they go for $5-8k around here and i got it for $2300, im fine with it. just turns out it needed more work then i thought.
mine is gold with tan leather as well. when i bought it i knew it didn't run right. had the code 41. was hoping it was just the tps. i already had 2 extras at home. also the rack leaked out of the column input and the pasenger inner tie rod was bad. but it came with a used rack, and also a set of eibach springs. had an exhaust leak as well. i changed the rack out. found out the moron broke the studs that hold the cat to the manifold on the driver side and tried welding the cat to the manifold. had to grind that all off and torch out the studs as they wouldn't unthread, even with a 2ft pipe wrench. put bolts and nuts through. now the passenger side has a leak in the same spot, but luckily not welded, just havent had time to get it back on my friends lift.
i also need to take the reservoir off the power steering pump and flush the filter screen out. sounds like it is out of ps fluid even though its full. same thing on supras when the screen is clogged. valve covers leak, contacts in the starter are worn out, so when they show up ill change them in the starter and the valve cover gaskets at the same time. i need a trans mount, and will do the engine mounts at the same time. found the rubber part only for like $35 each for the motor mounts. still havn't installed the eibachs yet.
oh, and i had to replace the cluster as he broke the speedo needle before i bought it trying to "change the bulb" as he put it. however the front seats and center console cover were recovered in leather like a month before i bought it, so are basically brand new. i'm trying to find a mint 95+ rear seat to match for cheap(has cupholders in the rear center armrest). has an amp and 2 12's, though i want to build a box under the back dash and mod the opening for a 10in sub so ill have the entire trunk back. hopefully i can get to that soon. already got the wood etc...
all in all its a project, but since mint they go for $5-8k around here and i got it for $2300, im fine with it. just turns out it needed more work then i thought.
Cool, i'd be interested to read about your 10inch sub in the back conversion.
How's your performance compared to the videos I have in this thread of my performance. Is your's faster?
Did you say you had to rebuild your ECU or buy a used one? and did it help?
I remember reading about you posting about the "moron who welded the exhaust after he broke the bolts" LOL poor you
09-01-10, 08:17 AM
#53
i had my ecu rebuilt by ate. didnt solve the problem, sent it back, they rebuilt it under warranty. same results. bought a used ecu, problem solved. as for performance, i cant watch your vids at work but my car does not take 11-17 seconds to get to 60mph. lol. its WAY faster then that. lol. oh, and i just remember i want to change the fluid in the rear end as i doubt it has been done in the last 60k+ miles
09-01-10, 08:53 AM
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I show a code 22 as an open or short in the Engine Coolant Temperature Sensor circuit, but you said you replace the ECT sensor, right? That could cause some of the problems you indicate. Anyway, I've attached a problem matrix from the manual that shows hesitation/poor acceleration associated with code 51 (switch condition signal circuit) and 31 (VAF sensor) as the top 2 most likely culprits, together with the diagnostic procedures for those codes. Hope it helps.
09-01-10, 09:48 AM
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i had my ecu rebuilt by ate. didnt solve the problem, sent it back, they rebuilt it under warranty. same results. bought a used ecu, problem solved. as for performance, i cant watch your vids at work but my car does not take 11-17 seconds to get to 60mph. lol. its WAY faster then that. lol. oh, and i just remember i want to change the fluid in the rear end as i doubt it has been done in the last 60k+ miles
What symptoms did the used ECU fix?
09-01-10, 09:55 AM
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I show a code 22 as an open or short in the Engine Coolant Temperature Sensor circuit, but you said you replace the ECT sensor, right? That could cause some of the problems you indicate. Anyway, I've attached a problem matrix from the manual that shows hesitation/poor acceleration associated with code 51 (switch condition signal circuit) and 31 (VAF sensor) as the top 2 most likely culprits, together with the diagnostic procedures for those codes. Hope it helps.
the 22 code was an airbag flashing code, not engine light
09-01-10, 10:26 AM
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Anyway, my new friend Blunden may help me stay out of the clutches of the rich Lexus mechanics
09-01-10, 03:27 PM
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Using terminals Te1 and E1 got code 25 from engine light - "Air-fuel ratio lean malfunction"
Using terminals Tc and E1 got code 51 from TRAC light - "Problem in engine control system"
Pulled EFI fuse and cleared codes.
Did Diagnosis Inspection (Test Mode) as per directions in the diagnostic procedures. Took it for a spin and simulated the 0-60 and kickdown problems I'm experiencing. Within a few minutes Engine and TRAC lights were on. When I got back I ran the codes like I did after work.
Guess what? Same codes.
code 25 from engine light - "Air-fuel ratio lean malfunction"
code 51 from TRAC light - "Problem in engine control system"
Called Lexus for a price on a new ECM $956.70 non-returnable
