I beleive my TPS has gone bad. I havn't been able to test it yet, though. Due to my multimeter quite literally melting while sitting in my old car last year. heh. Quite a spectacle.

My question, though... Do I need to calibrate anything if I change out the TPS? Or just Throw it in and go.

4.x or N*?

Bah, sorry. I forgot to mention that. :banghead: It's a 4.9L 91 Eldorado.

um, it can be adjusted if that's the prob you're having. are you getting any codes?

No codes or anything.

When I take off from a stop, or a near stop, my car will jolt off the line. Kind of like there is a dead spot on the very beginning of the TPS.

A week ago my car started to stall at low RPM's. I cleaned out the Throttle Body and that seemed to fix it. But it did stall once more just lastnight on my way to work. (JC Whitney, BTW...I get 25% off the top. So, contact me if you want a discount, heh) And I know the TPS may cause something such as that. My suspicion is mainly do to the jolting take off. Which doesn't always happen, either.

I believe your tps has to be adjusted if it is replaced, the adjustment is complicated. If your tps is bad a code should appear in the dic. I would look at the idle speed control first, try cleaning it and if the pintle is out all the way replace the unit.

Usually the TPS would set a code....


Clean the EGR tubes underneath the throttle body before you do anything else. While you are in there, clean the throttle body bore as well. Possibly there are some deposits built up in the throttle body bores that are causing the throttle blades to grab and cause the jerk you feel.

Just hold the throttle blades wide open and spray the bores with carb cleaner and scrub with an old toothbrush. You are just interested in cleaning the deposits off the surface...not cleaning out any passages or orifices or anything. Clean the back side of the blades while you are at it.

With the blades wide open, see the two tubes sticking up at you from the floor of the intake?? Those should be clean and not full of carbon. Rod them out with a piece of stiff wire to clean them out. Those are the EGR tubes and if they are clogged it will affect the EGR flow and cause a misfueling situation that could cause a driveability glitch.

Sounds promising. Thanks for all the help. I should be able to get at it tomarrow morning, So I should be posting any results by then. Thanks again. :-)


It's rather nice to know the TPS would generally throw a code. I'm use to driving vehicles where you could be missing damn near half the engine and it still won't throw any codes. Heh.

I got around to Cleaning out eh EGR tubes. The one closest to the firewall was packed at least half an inch deep. The one closest to the front was packed pretty decent but had a breathing hole poked through the middle.

After cleaning them, my engine seemed to idle a lot smoother and much quieter. I may be imagining it, though.

The EGR Tube closest to the firewall was loose, though. I could wiggle it around. Is this a serious issue? Or just something I should eventually look into fixing?

No problem if it is loose feeling. The tubes are just staked into the floor of the manifold from below. It can't fall out. It will just wiggle. They would do that when new sometimes. No problem at all.

Excellent. Thanks.