Rls4762

Just bought my first project car, an 86 trans am. Right off the bat on the way home it stalled whenever I came to a stop. Problem was "solved" by tightening the idle screw and opening the throttle more but after doing that the past few days to keep the car running it I would like to locate/fix the problem as the idle screw is almost as tight as it goes.
The car idles in park at about 1300 and drops to 700 when I shift into gear. Then it will either decide to keep running or it will stall. Stepping on the gas a little does not help, it actually kills it.
I'm thinking it's an air problem, but it could be fuel as the car had sat for four years.
Could not find any vacuum leaks. Replaced the pcv valve.
Was going to clean the throttle body and the IAC to start.
305 tpi.
Any thoughts or pointers?
As I said this is my first project car and I am still learning, I just know the basics at this point. Thanks everyone.

aliceempire

iTrader: (14)

Willing to bet there may still be a vacuum leak issue. They're really hard to find without a smoke machine or the like on a tpi. You can make a homemade one for cheap.

Rls4762

Oh alright. Is there one I can rent? I'd do that rather than make one.
As I was driving today a few more things popped up. The check engine light came on (no one will read codes without charging me 50 bucks), and when the car is on there is an electric buzzing sound (best way I can describe) coming from around the gas tank. I was worried it was the fuel pump. Should I change the filter and see if it improves? it did sit for awhile so maybe the filter is clogged from old gas and such. It doesn't sound awful, just noticed it when the light came on.
It's been a little more chuggy and it seems to hesitate when I step on the gas pedal, but once it gets going seems to be fine. Still having weird rpms. Thanks again, appreciate the help.
Love this site.

aliceempire

iTrader: (14)

I'd make one from a small paint can, tubing and a smoke bomb or cigar. Do a google search on it you'll find it. Can be made for like $15 or so.


A paper clip will read your codes too. Jump out the A and B terminals with it ad count the blinks. Then search the codes online/here.


Buzzing is common on fuel pumps. You may want to check your fuel pressure with a gauge to know what you have. YES, change the filter....never a bad idea.

Rls4762

Alright so I got a 14, 33 and 36.

Which are
DTC - 14 Engine coolant temp sensor error (high temp indicated)
DTC - 33 MAP sensor circuit error (signal high indicating low vacuum)
DTC - 36 MAF sensor error
DTC - 36 24x Crankshaft position sensor circuit error
DTC - 36 4T60-E Shifting Error

So I think 33 means I have a vacuum leak? 14 means I should replace my temp sensor for the coolant? Is that somewhere on the radiator?
Idk what to think of 36. There is an occasional grinding noise, or loud vibration, when I shift into reverse, but that hasn't happened in awhile. Should i assume it means the MAF sensor?
Will a fuel filter pull a code?

The 14 would explain the idle?

Sorry to bother so often, I could probably Google these things.

Rls4762

Rpms are way up in park compared to shifted into gear. 1500 compared to 700. That must be the vacuum leak. Is there a particular place I should look for a vacuum leak that would effect being in drive compared to being in park?
Thank you thank you thank you

aliceempire

iTrader: (14)

The cts could be a pinched wire(s). Sensor could be bad too. It's in the intake manifold at the front. The cold start temp sensor is next to it. It could affect idle...the ecm doesn't know what temp the engine is at.

33 and 36 are both maf codes on your car I believe. The trans will not show a code on these cars. Bad sensor? Bad wiring....possibly same wiring the cts may have an issue with? Not too sure if a vacuum leak will cause these codes... I'm more familiar with speed density systems. Search those maf codes, I'm sure it'll give you lotsa possibilities to check.

A fuel filter won't cause a code.