Boostd

iTrader: (1)

Decided to change spark plugs and spray cleaner around throttle plate to clean off carbon. First, let me mention I did not disconnect battery. After install, I started the car up. It started fine. Started home. Got about two miles and noticed the tach acting funny and seemed like I had to push harder on the gas to get the car to go. Still driving home, I now notice that when I try passing gear by pushing down on the accelerator that the trans is not kicking down into the lower gear but just accelerating normally but not with the rush/power that I had before this maintenance. Basically, it seems to run like an IS250 instead of 350. Doesn't have the kick back in the seat power it had a hour before. I now also do not hear the tick tick tick of the mechanical fuel injectior pump that I did previously which would explain why I am not feeling the power from those direct port injectors. I took the car into the dealer and they tell me because there are no check engine lights on that everything must be ok..I need your help hopefully with an ASE Certicitied Lexus Tech/Master to chime in with his toughts and what he thinks shoud be down to fix this car that ran hard and fast before this maintenance was done. Service advisory tells me the heart level is good and car seems to run fine. I have yet to drive it. the dealerships was very busy which i hate becase they wast the cars fixing under their timr limit. the car was a scalding dog before i changr plugs ato try tp gain a grip pon wprl thath nrrfing to be done anyway...... what are my options to get this thing running as gppd as it did,. Now it just puts. When i want to kick it down a gear witht the gas pedal soemthing like the throttle plate is not telling the direct injectiors to start going their jobs.

Any help would be arreciatede. Did i miss something I shoud have down.

Thanks in advance...

the nice peope at Lexus tell me my car works goood and that show no check engine lights our on and my heath meter lookede great. i basically saw somethingis wrong

Can anywho is ASC Certicied to shine some light on what i have done., I am at a loss today after they told me that. obviouly you need a check light on for anythigng to get fixed at a dealler...Just told me no light and all their heath meters looked really good.

Please add you comments for i can try to justify all this. in case i didtion mention was tje the car downsfifted into the next gear fairlly easy. I am a lose of woords right now that with all the scanners they have woud surely be ablre to fix ths issue., Til, i guess i'll be driving an IS with only one set of injectior on it. I want my power back back and when i stop down on tje gas i wont the motor to wake upo like it should. thats is advavne friends!!!!!!! I appreciate your time and help.

ArmyofOne

Check the gap. I would bet money THATS where your problem is. 9x out of 10 even new plugs need to be re-gapped/adjusted.


If thats good, could you have bumped the throttle position sensor? It sounds like thats whats happening, the TPS sends a signal to the ECU that says how far the pedal has been pushed, and the ECU adjusts fuel and other things accordingly. It MAY not be out of whack enough to throw a CEL, but it could be just enough to cause the symptoms you mentioned.

Also, check all your vacuum lines on the intake. A vaccum leak may not cause a CEL, because it is not linked to any electronic systems (typically) and if they reversed/crossed one of the smaller hoses, it could cause this as well.

mitsuguy

iTrader: (2)

Hard to say exactly what kind of problem you are having without a check engine light, but, did they attach a scan tool to the car? Sometimes the car will flag a code but not turn on the check engine light until it has repeated the problem enough times. Your car should be drive by wire and with that, I am sceptical of your throttle body cleaning. It is imperative on drive by wire systems that it is cleaned properly and not just hosed down with cleaner.

I also agree with Army - fair chance the new spark plugs were not gapped correctly, even if they were supposed to be. Hard to say without checking.

I would try and get someone with a scantool to see if there are any pending trouble codes...

let us know...

Boostd

iTrader: (1)

Thanks, when I did put the plugs in a few may have been like .45 but I thought with that being such a small difference wouldn't have made a difference. Lexus did say they hooked it up to their diagnostic machine and the service rep told me that it didn't even have any stored codes in it and said that was weird. I didn't think I sprayed enough cleaner for any to leak into the throttle body and hard to believe such a small difference in a gap would cause the car to run the way it is. I am going to take the car for a drive with the tech and ask him if it feels like an IS350.

Also sorry for so many typos in my post. I was typing last night and obviously couldn't see half the keys.

Boostd

iTrader: (1)

Would a small difference in the gap be enough to shut off the mechanical pump? That is a thing I noticed almost immediately after putting the plugs in. I no longer heard the loud tick tick tick from the mechanical pump. The more I thought about it is how could such a small difference in the gap cause the car to act like that. Also, would this cause the car not to want to downshift when giving it enough gas to cause kick down?

Boostd

iTrader: (1)

One more thing I forgot to mention is before I started changing plugs or cleaning the throttle body I did not disconnect the battery. Would that have something to do with the way it is running? Does the battery have to be disconnected before pulling out coil packs? I thought maybe by disconnecting coils from the plugs it may have tripped something in the computer or is that something that resets everytime the car is started?

What should I tell the tech when he drives the car and it doesn't want to kick down when the gas pedal is pushed? Do all these techs simply go off what Lexus's diagnostic machine tells them? What about driveability issues with no check lights?

What are the odds that something in the throttle plate was damaged by the cleaner? In my mind I didn't come close to spraying enough to cause that kind of damage and wouldn't a check light come on if something was damaged in the throttle plate like servos, etc?

RTIS250

iTrader: (9)

First question would be, what spark plugs did you install in the car? If you used factory iridium plugs, then they come pre-gapped and its not advisable to adust it. Besides, ive seen cars with as much .10 difference in gaps from plug to plug and it doesnt really make a difference. These modern coils have such high output, it doesnt matter.

Secondly, yes, not disconnecting the battery WILL effect how the car runs after cleaning the throttle body. The computer knows exactly where to put the idle at, as it has learned over time with the build up of carbon. When you clean it, it no longer knows where idle is, and has to relearn. It takes a while to relearn after cleaning. Its easier to just disconnect the battery, let it lose its memory, and let it relearn after restarting the car. Idle is best learned with the ebrake on, running in P. After its run for a bit, you can shift to D, keeping the ebrake on, letting it sit there for a bit then going to R... repeat a few times. Also helps to cycle the a/c on and off. Then you're gunna need to drive the car for a while to get it all relearned and set up right.

Do this, and see if your symptoms go away...

Boostd

iTrader: (1)

Thanks, I just rechecked the plug gap and reinstalled plugs. I also disconnected battery and let it reset. Upon driving the car still seems like it takes alot more pressure on the gas pedal to get the car to drop down a gear when driving. I still think that some cleaner may have damaged something in the throttle body that is causing the car to respond to the gas pedal. It does run ok and doesn't miss but just doesn't seem to run like it did before. Very odd. Could enough cleaner have somehow dripped into the servo's in the throttle body to cause the lack of downshift. I know it is hard to describe in words how it drives but I am really regreting spraying any cleaner into this throttle body.

What else sends a signal to the computer to tell the transmission to downshift under load. Even when going up hills the car seems to act like it doesn't want to drop down a gear until I almost floor the car. Do I need to buy a new throttle body to fix this problem? Like I send in the first post, I have taken the car to Lexus and they ran a scan and had a complete printout of the specs of what the car read out on their machine and nothing stood out to them. If I had damaged the throttle body in anyway would a check engine light come on?

Thanks for your help!

RTIS250

iTrader: (9)

If there was something damaged in any sensor in the throttle body, youd get a check engine light. These systems are extremely sensitive and will throw a code for any abnormality. As far as the driveshaft goes, no, there are no grease fittings or maintenance that needs to be done. There isnt much to it, a couple rubber flex discs and a center support bearing. I doubt youre getting any binding from the driveshaft. Did you have the ECT power on before, and its not on now? That would certainly account for the difference in the pedal feel.

Boostd

iTrader: (1)

Here is the diagnostic results of when they ran a check on my car. Do any values seem out of line in reference to the symptoms the car is having on down****s, etc.

Thanks.

mitsuguy

iTrader: (2)

Honestly, everything looks good, save a high long term fuel trim... looks like it reads like 16%, but, that isn't terrible either...

Only 120ish miles since the last reset of the codes though, was there anything else going on recently with it that it was reset???

ArmyofOne

I cant see anything wrong with the diagnostic test results...other than the high fuel trim...Cody, do you think it could be stucck in open loop?

Its weird, because any variation AT ALL, outside of spec, on any sensors or within the system itself will throw a code. These are not the OBDS's of the 90's. Long gone are the days of jumper wire and "counting the blinks" on the CEL.

Check your throttle position sensor out. Cody, do you know the voltage limits for the TPS? It should be like .00v-2.5v or something like that, its not much.

Boostd

iTrader: (1)

Thanks guys. I hope I can one day get this fixed. Lexus says there isn't anything wrong but I disagree with them. I wish they have hooked the machine up while they were driving it as I am sure they might have seen a problem. Why didn't they hook up a meter and get readings while driving the car not by having it sit idling?
Is the TPS located in the Throttle Body? How do you adjust it? Car still doesn't have the bottom end pull and I still have to almost floor it to get it to downshift. Very frustrating. I am driving my Maxima while my Lexus sits in the driveway. In regards to the throttle body, would it be hard for the cleaner to get thru the blade seals to possibly damage it? I just know that after the cleaning things went bad. When I cleaned it, it was more of just a few sprays around the body and wiped clean with a clean towel. To my knowledge, I didn't bump or move anything including the blade. The main drive problem is it just doesn't have the pull off the bottom and when driving when I apply throttle the car just wants to stay in a low gear and not react the same to gas like it did before. This is driving me crazy. I can't believe how sensitive these cars are.








p

Boostd

iTrader: (1)

RTIS250, mitsuguy, and Army what would be my next try be. What does the process of idling in park, reverse, etc. do? Does that set the computer to those specific values that wil correct these problems. Is the lack of downshifting caused from the throttle body, throttle position sensor? What about the lack of hearing a noticeable mechanical fuel pump tick tick tick like I did before I cleaned out the throttle body. Can the throttle position sensor be in fact adjusted? Like I said before, when I would be excellerating I could get on it a bit and would click down one gear and more gas would drop it another very precisely. Now I have to hammer down on it and it only seems to want to drop one gear down. Seems very irratic in it's operation. What does the transmission module have to do with my problem. I am trying to learn this car as I have come from a Nissan Twin Turbo 300ZX which was straight forward and easy to work on. I like challenges but honestly don't know where to start without being at the mercy of the dealership. The day I took my car in they were covered up with cars to work on and since I had no CEL on they were really just trying to get me out the door even after I told them it still wasn't running right. Is the normal process to hook up the scanner and take the car for a drive and record values as the car is driven and under many loads to check out the shifting problems. I did reset the computer after I changed the plugs to see if that would fix my problem but it didn't.

Going back to when i changed my plugs and started car up right away about two blocks down the road I noticed a sputtter and the tach bounced up and down several times and seemed to start idling a little low when at park. Ever since that point I started to encounter the lack of downshift problems, even when driving up steep hills the car would want to upshift into the next gear when it should have stayed in a lower gear for the pull up the hill..I am thinking something in the throttle body is malfunctioning and sending bad readings.

Thank all you trying to help me solve this problem or how to approach Lexus so they can narrow the problem down and fix it. Can these TPS's be abjusted manually and in regard to the fuel trim that was mentioned what does that actually control? COuld that be a reason I don't hear the otherwise very loud mechaincal fuel pump. In my opinion, something wrong with the car not getting the signal to the direct injectors to make the power. Could I have some broken the throttle body that wouldn't show a code for some reason b/c it is within values. The car ran so smooth before this and that's what makes it frustrating.

I appreciate you all for trying the work me thru this. What should I try next?

mitsuguy

iTrader: (2)

If I was having this issue, I would get a simple volt meter and check voltage from the throttle position sensor first... under full throttle, you should see close to 1.0 volts and with no throttle at all, somewhere around 0 to .1 volts...

start there...