Relearn for tps?

[lvemy3100]

Originally Posted by AaronGTR

No, opening the throttle with the ignition on doesn't do anything except send a voltage signal to the PCM. Injector firing is based off the cam sensor signal... if the engine isn't running the cam isn't rotating... no injectors firing.

I found this info about the TPS learn on the DHP tuning forums. Thought I had posted it here before but I couldn't find it either so, I guess not.

I too could have sworn you posted this before so I was actually waiting for you to post a link to the original post but I cant seem to find the post from you either...

mods please sticky this as its great info and will save many people lots of headache and money.

[350rs]

Well. it worked and it didnt.. haha

it starts and idles fine when cold. But if i go somewhere and stop for 15 or 20 mins, come out and restart it.. its high again. However not as bad. In drive on the brake at a stop light its about 900 instead of 1200. Now i didnt buy a new TPS again. i just did the relearn on the old part. Could that be the problem?

[AaronGTR]

Originally Posted by 350rs

Well. it worked and it didnt.. haha

it starts and idles fine when cold. But if i go somewhere and stop for 15 or 20 mins, come out and restart it.. its high again. However not as bad. In drive on the brake at a stop light its about 900 instead of 1200. Now i didnt buy a new TPS again. i just did the relearn on the old part. Could that be the problem?

Shouldn't be. As long as it's working properly and you did the relearn once, it should be all set. Of course as I said you'd need to look at it with a scanner to be sure, but it should be fine. Any further trouble should be something else like IAC valve or a vacuum leak somewhere, etc.

[350rs]

daaaa gremlins.. i hate them. the iac is newer than the TPS and i did the correct install on that part. i havent noticed a vacuum leak unless there is something that would be intermittent vacuum??

[westerndragon]

do the starting fluid trick on the vac lines. carefully spray the lines and if the engine revs you found it some small leaks or a crack in a line can be intermittent

[350rs]

did that. the only reason it wouldnt work is if it somehow had a vacuum that wasnt ALWAYS there. somehow.. i dont know

[westerndragon]

wiggle the lines as you spray them and you might get the little crack to open up....omg i think i just sounded like sik....you know what i mean haha

[AleroB888]

Originally Posted by AaronGTR

The TPS itself and it's position is not adjustable... but the PCM's reading of it's voltage signal IS and there IS a procedure for teaching the PCM what voltage corresponds to 0% and 100% throttle position. The car will NOT learn this itself just from driving.

I discovered this after installing my 65mm TB and adjusting the throttle stop so the plate closed and opened properly, but at idle my scanner was still seeing 0.7% throttle, and at WOT is was only seeing 98.8%. After doing the relearn it reads correctly. So here it is...

Turn ignition key to on (but don't start engine) and leave it for 10 seconds, then turn it off for 10 seconds.
Then push the pedal down as far as it will go, turn ignition key back to on for 10 seconds again, then turn key off, then release pedal and wait another 10 seconds.
Repeat this 2-3 times to make sure it's got it. If you have a scanner you can verify it. With the ignition on and foot off the pedal it should now read 0% throttle, then push it down and the percent should rise until you are at 99-100% at WOT position.

Thanks, printed that out and put in the glovebox.

Now I noticed there is a range of adjustment on the throttle plate over which I still get a "zero" reading on the scanner for TPS%.

On my old stock TB, I can see just a bit of clearance past the the blade, but I can't remember if I had adjusted its position before. Should it be completely closed, or is there a specification for blade clearance? And I have seen some models with a pinhole through the blade, some without it.

When I monitor IAC position, I am getting anywhere from zero to ten or so for a reading at idle, in Park or cruise with closed throttle, then much higher at open throttle. Does anyone know what I should be reading on that?

[AaronGTR]

0-10 at idle seems kinda low. Sounds like the throttle plate might still be open a tad too much so the IAC doesn't have to open far to keep the idle. I know I've read it somewhere how much IAC is normal, but don't remember exactly. I'm wanting to say it's like 20-30 is normal? I'd have to look at mine.

Anyway, with the throttle plate, I was told that basically you should adjust the throttle stop down until the point the plate closes and feels like it sticks a little bit when you open it up by hand, then back it out again a tiny bit so it opens and closes by hand freely without sticking. You should not see hardly any light around the plate when it's closed. If you see some gaps around it, or it's not closing far enough without hanging up on one side, you can try loosening the torx screws in the shaft that hold the plate in and adjust the plate position slightly. Close the plate to a point that looks good then tighten the screws back up and check the movement. Repeat as necessary until it's smooth and there are no gaps. It can sometimes take a while.

[westerndragon]

One vote for Sticky

[350rs]

ill put up 30 votes to that one. coulda saved me a lot of money and headache knowing that years ago.

[AaronGTR]

I'd do it myself if I was a mod in this section. Jeremy sent me a PM like over a month ago saying he'd make me a mod and I haven't heard anything back yet?

[350rs]

Hmm.. my high idle returned a few days in a row so i tried that relearn. Been about a week now with zero problems.

Does that thing "lose" memory? I dont think i did it after i did the whole engine rebuild. So it might have just still needed to be done. At least this was a free and quick easy fix this time. haha

[AaronGTR]

Nope, once it's set it should be set. At least... I've never heard of it being reset like the fuel trims do when the battery is disconnected for a long time. It definitely won't just change on it's own though. Only way I've heard of changing it is if you do a full write or if you re-do the TPS learn procedure. Should be easy enough to check though. Just watch the gauges on a scanner and see if the throttle % is still at zero when you are idling, and it should go to 99.xx% when you floor it.

[350rs]

well all is well now, so im not gonna mess with something that aint broke. ya know? I was just wondering what may have caused it.

[350rs]

its back.. and its REALLY pissed this time. Its without a doubt the TPS. I started it and it immediately shot to 2500 or so. Got out and popped the hood. Unplugged the IAC, no chance. I unplugged the TPS and it went right to proper idle ( 1000 RPM give or take on cold engine). So i wonder if its something in the wiring itself? Id have to trace it back as far as i can. That whole area of the harness was hacked on pretty bad by some kind of parking lot mechanic. Im not even going to give whoever this was the dignity of being a backyard mechanic. No lights or anything though.. what would happen if i were do drive the car with the TPS unplugged all together? I revved it a bit by hand while i was there and it didnt seem to run strange at all. Which seems off to me but hey whatever.

[AaronGTR]

You definitely can not drive it without the TPS. It's used for too many things like load calculations and such. Especially the switch over point from closed loop to power enrichment mode. With no TPS signal, the car won't know what to do.

[350rs]

i didnt figure. It was shifting kinda strange today too. I assume the tranny uses signals from that freggin thing as well.

i see gmpartsdirect.com has them for like 38 bucks. Are they worth getting from them or just a parts store?

[AaronGTR]

I'd say get it from wherever has the cheapest price. Are you sure it's the sensor though or is it the wiring? Have you replaced the sensor before or no?

[350rs]

yea i have. So it SHOULD be fine. ill be checking the wiring before i get anything.