itmedylan

My car (1988 rs with a 350 tbi motor) when i first start it from a cold start it'll idle a little high for a while then go down (but drives great) and after it warms up it will have a fluxuating idle. when i drive it it'll start to cut out either like its getting too much air or too much feul, in the last week i have replaced alot of parts trying to fix this problem such as : spark plugs, temp sender, tps, iac, both injectors, feul regulator, map sensor, feul pump, feul filter. i am running out of things to replace. any ideas? i just bought the car 2 weeks ago and when i got the car it had a leaking injector so it ran really rich, could it be an 02 sensor causing this problem?

UnderCover89TBI

iTrader: (25)

im battling a similar problem. but mine is at idle. it'll bounce then die. I have changed numerous parts to no avail. any reputable automotive repair facilities in your area you can possibly take it too?

Sometimes the tps can be changed but may not be functioning properly. has to have certain parameters.

It is possibly your ignition control module is malfunctioning. it is about 45 dollars new (although I do recomend buying an AC DELCO version, which could be more).

ex-x-fire

Check the grounds carefully, esp. the ecm grounds at the back of the heads.
Check the coolant temp sensor resistance at different temps.
The tbi base gasket has known to go bad & cause a vacuum leak.
The tps is slotted, it has to be set to the proper voltage.

UnderCover89TBI

iTrader: (25)

The tps on my car is not adjustable.

itmedylan

my tps isnt adjustable either, i ran some codes and i got a map sensor code, but my map sensor is brandnew im going to check the ground for it and maybe make my own ground.

The reason i replaced temp sensor is because when the car was running bad i could un plug it and it would run fine for about 2 minutes then it would act up again but even since iv replaced it its still acting the same. same with the map sensor i will unplug it and it will run okay for a bit then go back to running like s**t.. maybe bad grounds on each of them, i also wanted to check to see if my vacuum hoses where hooked up in there correct spots is there anywhere i can find a vavuum diagram?



thanks for the help guys,

gmstrong

Check the map sensor vacuum line

itmedylan

iv replaced it... along with the other vacuum hoses.

gmstrong

Did check the connector for power?put your finger in it a turn the key.JOKE.Get a test light and check it out.

itmedylan

yes its getting power and proper ground

Elfanzo

Im having sort of the same problem. except i got rid of the idle problem with bad plug wires. Now it wants to cut out and sputter with no power when i go down the road. The engine just wants to fall on its face. Think it could be my timing or that module? Ive never checked my timing before.

Stevolwevol

iTrader: (1)

I had a similar problem and it was the TPS.