StevenB L98/LS1

stock 91 trans am 350 tpi i had the distributor replaced this same time last year, that was the cause of my idle problems. And now when the car is warm you have to come to a complete stop gently or the car starts to surge and shake. It wont die, but it surges. And when i put it in park, it idles a lot rougher. then u kick it back into drive, the car idles just fine. I feel like a dumbass now after replacing all this, i replaced the idle air control value, it helped, but did not solve the situation. The car is still drivable, but not drivable like anybody else would like it. After i replaced the value i changed my tps AGAIN thinking it was problem because it felt like the same symptoms as when my old tps went out, because it would hold a steady rpm just when i would do...... 35 mph and the rpms would race between 900 and 1000 constantly. The tps didnt change what the car was doing though, i changed out MAP sensor that didnt do it either. Ive run out of ideas, and ive checked my vacuum lines, the only thing im not running is the EGR Solenoid which i have the vacuum lines to that plugged off. Could it be fuel filter? Distributor cap, rotor? i doubt it is, but im pretty much out of ideas until the shop opens up on monday.

If it helps, idk if it was just a coincidence but it didnt start doing this until i kicked on my ac in my car a few days ago, and ever since i turned it off, its been rough. could an ac switch do this? seems unlikely but i could be wrong.

patricksmithahh

i would check fuel filter and fuel pump...ohm all your injectors check plugs wires cap and rotor first

sounds to me like a fuel delivery problem

StevenB L98/LS1

you seriously think its fuel issue? it some what makes since. sometimes i can leave a light after im stopped and once i take off, the car will kick up the rpms like a injector is slugglish, but im not sure. But when i drive the car its a blast to drive, nuthin is wrong, i can get on it, and it will go. Its only when im sitting at a light idling, and once i take off it acts weird.

patricksmithahh

could also be an intake air temp sensor it could be sending wrong signals like when the car is cold it could say its hot or vice versa

patricksmithahh

but lets say your fp has a short in a wire or is just plain goin bad then that would explain having to come to a gentle stop or else it surges/stumbles

StevenB L98/LS1

Well since im about to start going back to work, i wont have the time to do anything else with it til monday, and ill just drop it off at my mechanic. The car just has very strange symptoms right now ive never addressed before. How the car just goes down the road perfectly, and then coming to idle it just stumbles like crazy, until it hunts and searches for the right idle speed, gas milage lately has been worse, but i didnt think this could happen the way i described.

StevenB L98/LS1

Okay guys IM STUCK i let my machanic that literally knows his stuff when it comes to third gens, and he called me back today saying after keeping the car for a week straight he has no clue whats wrong. Okay now im starting to worry what the hell is going on. The description of the car of what it was doing is detailed in my 1st post. Struggling to idle in park, and then once u drive it surges once down to idle, and and skips while your going down the highway at any speed. Terrible gas milage lately. What could it be?

JulieGTA

Did you ohm the injectors? do a search.

Is the car stock? Did you replace anything lately? It could be a vacuum leak.

Is it showing any code? Why is the egr unplugged.

StevenB L98/LS1

i have literally replaced everything on this car since ive owned it, only thing i havent rebuilt is the internals in the motor which are fine. EGR is unplugged because it wasnt working regulardless because the egr solenoid was cracked no presurring vacuum going into the egr. No i havent but i dont have the tool or pressure tester to do it, hoping that a shop would have the brians to do it.