Gas Pedal or TB sticking - UPDATE with solution!

kc2005ptgt · Post by **kc2005ptgt** » Sat Mar 03, 2007 12:59 am

I am not sure, I did a search but it wasn't what I was looking for - this is NOT a vaccum problem, nor is it getting stuck open - when I press on the gas, SOMETIMES it sticks and I end up pressing it too far and the car lerches forward or jumps... other times, it is really smooth... I am not sure when then started, but recently it has been getting worse. Tonight, while delivering, I had more than the usual stick-age... I am getting tired of it, and I can not find a solution. Could this be the gas pedal, or the cable, or the tb?

What kind of lube does the TB take? It is almost 6 years old (It is an LFS 60mm TB), so maybe this is the problem, I am going to pull it off tomorrow and check it out.

What about the gas pedal? Is there any sort of adjustment I can do to it, loosen it up, tighten it up, what? Lube it also???

And finally the cable, I am afraid that anything is wrong, I did however reroute it recently and placed it through the intake mani instead of on top of the coolant line from radiator to the neck... maybe this caused it? I can try and route it back to normal, but I am wondering if anyone else has this problem???

Thanks all.

Knoxville_R/T · Post by **Knoxville_R/T** » Sat Mar 03, 2007 1:07 am

Yes the LFS TB has this problem, I can not quite recall what the fix was, but i believe it is the TB itself. Hopefully Diablo or someone else recalls the answer.

I would personally sell the LFS and get the Modern one. Had it for 2 yrs and never a single problem, unlike most LFS owners..

nofrills05 · Post by **nofrills05** » Sat Mar 03, 2007 1:12 am

My car has done the same thing too, it is intermittent. I'm interested to see what people have to say.

OB · Post by OB » Sat Mar 03, 2007 1:13 am

Not sure if our issues are related, but im having a similar problem with my car. The throttle occasionally feels very stiff. It seems to happen every single time it rains. Thats the part that baffles me. How could rain cause such a thing? Ive come up with a very far-out theory, but when I come back and remember what kind of car I drive, it makes it seem much less likely. Here it is: our cars have both a TPS and a APPS (accelerator pedal postition sensor). MAYBE, if the car could some way know it was rainin outside, it could adjust the tension on the throttle to prevent traction loss due to hard accel. How this is possible is beyond me, but its really all I can think of.

Its not like it gets cold enough in CA for anything to freeze or even come close, and this problem doesnt even usually happen when its only cold. ONLY when its raining/wet. Ive ran this by several people and no one has really heard of such an issue (aside from a sticking/dirty throttle plate), nor do they have any suggestions fixing it. Ive mentioned this before on the forum with no success. Its been happening pretty much since I got the car in 05. Heres the kicker though: it happens on my gfs 05 neon as well. Anyone who can explain this and figure out wtf is happening is amazing.

Knoxville_R/T · Post by **Knoxville_R/T** » Sat Mar 03, 2007 1:15 am

PM nodestiny. i believe the throttle plate would get stuck. He had this problem with his.

From LFS's site, see if this might help:

* If throttle sticking occurs at the start, loosen the jam nut that adjusts the throttle . Then screw the idle screw up just a hair till it stops sticking then re-tighten the jam nut. DO NOT screw it up too much or this will increase your idle to much. You can test it with your hand opening and closing of the TB plate. If you don't feel it sticking then reinstall it on your car. If it does you need to raise the TB set screw more till it stops.

underway · Post by **underway** » Sat Mar 03, 2007 10:54 am

well OB maybe ur prob is the throttle cable sticks becuase of humidity witch is when it rains...just a thought

gilly02le · Post by **gilly02le** » Sat Mar 03, 2007 11:07 am

i'd change your throttle cable back, Just for now, Lube the throttle body... with grease, you will probably have to take it apart a little bit, so you can grease the TB Shaft. I think part of the problem is that the LFS throttle bodies do not taper, like the stocker. (at least i think they don't taper) which probably makes it harder to make the plate fit in there tight..maybe too tight in this case.

kc2005ptgt · Post by **kc2005ptgt** » Sat Mar 03, 2007 12:02 pm

what kind of lube/grease do I use??? And where do I grease it?

kc2005ptgt · Post by **kc2005ptgt** » Sat Mar 03, 2007 1:49 pm

ok, so here is what I have done and so far it worked...

I went out, took off the TB and brought it inside for a quick clean and adjustment...

First thing, I cleaned it out, because there was much carbon deposits and grease/oil in it - to the point it looked black

But now consider this, it was bought back in 00 or 01 and so I got it from someone else who never cleaned it up, and then I never cleaned it myself, so there was about 5 yrs worth of deposits in it, causing the throttle plate to stick when closed. Not only that, but the plate itself is not perfectly fit into the throttle itself; since it does not taper at all, the plate would get 'shoved' to one side and cause it to temporarily stick while the car was running. When I cleaned it out, it helped a lot, but would still get a bit stuck.

I noticed there was no screw to adjust the throttle/idle... so I found a nice bolt the fit into it and stuffed it in the hole, and adjusted it so that when I held it to the light there was barely a noticable pinhair of light around the tb plate (which is how I found out the thing does not sit perfectly it). I put it back on, and immediately I noticed a difference. The car responds much better now, and a quick test drive shows that it responds like new.

I am warming it up and going to take it for a nice long drive to double check - I will update, but for those of you wondering, the idle adjustment is what worked. Also a quick clean helps.

Thanks for the helps!

neonpla · Post by **neonpla** » Sat Mar 03, 2007 2:13 pm

i had the same problem with my MPX TB it was because the screw that you use to adjust the idle had somehow fell off thats why my tb is off till mpx sends me a new screw.

nofrills05 · Post by **nofrills05** » Sat Mar 03, 2007 11:14 pm

Going to try this fix, hope it's the same for my modern TB

OB · Post by OB » Mon Mar 05, 2007 12:21 am

so does anyone else have the problem with the stock tb? any of you 05 owners? im thinkin it might be a problem specific to the newer ones since no one has really heard of the issue. seems like all the aftermarket tb guys have the problem, but my tb is clean as a whistle, and my car's still brand new.

bigbird · Post by **bigbird** » Mon Mar 05, 2007 7:18 am

OB, I have an 05, but do not have this issue. Since it is so new, you might just take it to the dealer and let them deal with it!

OB · Post by OB » Tue Mar 06, 2007 12:10 am

^yeah I thought about it, but its one of those problems that is pretty unpredictable. My car had a no start condition (and still does every blue moon), but of course the one time I took it in it didnt do it. Sometimes when I go to crank it over, it idles real low for a second or two and then dies. I did find that a quick tap on the throttle fixes it and it starts right up. very wierd. hardly ever happens anymore. There's nothing more frustrating that diagnosing an inconsistant problem.