I just replaced the TPS on my 1989 Lesabre. It was doing the same thing -started, revved for less than a second, then would die unless I gave some throttle.
Replaced the TPS with one I had laying around and all is good now (except mpg'* -210 miles on 16 gallons, 80% freeway )
Now to find my mpg'* culprit.

Water is heavier than gas.

Well, I didn't get it going today. Here is what I did and what I found out.

I replaced the fuel pressure reg and that did not help.

I cleaned the AIS motor and that was no help.

I inspected the EGR valve and that appears ok.

I went and rented a code reader and pulled two codes, they are both P0300.

Those will set when the car is running. I can force the car to keep running by revving the heck out of it and keeping the RPM'* above say 2000 to 2500. When I try and feather it down to the normal range the car sounds like it is running on 3 or 4 cyliners.
Above the 2500 rpm mark it revs freely and sounds relatively good.

I then took the coils and the module under it and had them tested and they all passed saying they were good.

Tomorrow I am going to try and borrow a snap on scan tool that might give me a little more information.

thanks for your ideas so far
Keep them coming and I will keep you informed.

thanks
Andy

Forgot to mention that the fuel pressure stays around 48 to 50 when we are revving the motor to keep it running.

Andy

Andy - while you are at the store...buy a can of dry gas. pour it in.....if it'* crap in the fuel that'll straighten it up after a little running. And it sounds like you are trying all the right things. What'* another $2 (max) going to hurt?

Doubt it'* the problem...but I hear you.

Bill

Thanks for reminding me. I will stop and get some today and give that a shot also.

Does anyone think that these symptoms could be caused by a crank sensor on its way out?

Andy

The crank sensor is HIGHLY unlikely.. like I said before, it either works, or it doesn't. But then again, these cars are picky.


-justin

Hi all

Here is the latest. I brought home the snap on scan tool and decided to look at the misfire information. Here are the number of misfires on each cylinder:

1 25
2 10,084
3 17
4 469
5 9756
6 3239

Now I got looking at the high number of misfires on 2 and 5 and thought that it was going to be a coil. I swapped the number 2 and 5 coil with the 1 and 4 unit. The problem stayed with cylinders 2 and 5 mostly. 1 and 4 looked good. Now I did have the ignition module tested at Autozone and they ran 5 or 6 tests on it so it would heat up and each and everyone of the tests pasted.

Does the PCM have anything to do with individual cylinder firings? It does calculated the timing right?

I may make a run to my local u wrench it and see if I can get an ignition module to try.

Keep your ideas coming.

The dry gas is in but did not help me.

thanks again
Andy

Could the bad grounds that are mentioned on this site be causing the type of problems I am having?

I am off to the Library to see if their Mithcell on demand has any ideas.

thanks
Andy

The problem turns out to have been the large vacuum line that runs from the brake booster to the upper intake manifold on the back of it. It is probably 1 inch in diameter and that end at the manifold popped out. That huge vacuum leak is what was causing all of my problems.

This is one for us all to file away incase it happens to someone else.

Thanks for all your help

Andy