My '85 TA is expieriancing bad idle and stalling when in open loop mode. The engine is a '89 305 TPI. The ecm and wiring is still the crappy '85's.
What would cause this in open loop? Doesnt the computer control everything then.
I dont have a CSI, the IAC has been replaced, the MAF is good(as far as I know), fuel pressure and pump are good, the cap, rotor, wires, and plugs have been replaced last fall, the coil is an accel super coil. What could it be?
When I shift into reverse or into drive it stalls. IF I turn the wheel sharply, it stalls. Sometimes the idle bounces. When I try to drive away, the car acts like its bogged down or it has to charge up or something, then it moves(when i give it gas it bogs down, the rpms are low, then they suddenly spike and the car takes off)

In closed loop everything is good(except sometimes it starts and dies right away, then I just tap the pedal when cranking and it starts fine).

Any ideas?

Thanks,
Matt

 

Same situation.

 

First thing I would check is for vacuum leaks. Do you have a scanner or a datalogger?

 

i had the exact same problem and i found out that the dude who put my air foil in put it in sideways. i was also told to clean out my IAC hole on the bottom of the throttle body which i havent had the chance to do yet. also i tried resetting my computer it helped also

 

i forgot to mention this happened on my 85 t/a

 

How the heck do you put the air foil in sideways???

 

91blackgta- I dont have a data logger. I did check for leaks by spraying starting fluid around the engine, no leaks found.

I am begining to think it may be leaking fuel injectors. I checked my fuel pressure. While running its aroun 43-44 psi. When I turn it off, the pressure drops, slowly but steadly. I stood there and watch the pressure fall to about 25psi, where it then stabilized for a minute, then started to bleed of again.

Anymore ideas?

Thanks,
Matt

 

i asked the same question about the air foil it confused me

 

there's a dirty (kinda rednecked) way to test the injectors for leakage. I have heard people here on this site talk about doing it. I have never attempted it, so done get mad at me if it doesn't work. Trying to cover my @ss. Take the plenum and runners apart. pull the rail off with the injectors on and keep the fuel lines attached. hold the rail up in the air a little or to the side if possible and have a friend turn the key to the on position to prime the system. Watch the injectors to see if they leak. be careful, were safety glasses. I am not sure if there is enough slack in the rubber fuel lines to be able to test like this. I would also recommend doing it when the engine is cold. It's up to you. It is a lot of work, but you can actually see if they are leaking or not.

 

I cleaned out my IAC sensor hole and sensor the other day. the car started fine the next morning. no hard cranking nothing at all. now here i am like 3 days later the damn thing is back to its old ways of taking forever to fire up and a little bit of white smoke when it starts finally. also the car will idle really rough and go up and down as it is warming up once the car is warm it is fine. it starts fine and whatnot also when it is warm what could this be?? someone told me i need a new ignition coil and distributer cap. ive also been told injectors and TPS and O2 sesnsors

 

The simple fact is, you can guess at this , try this, try that, but the EASIEST and QUICKEST way to diagnose any car with a ECM is with a scantool or a cheap old laptop w/ some free data software and a cable to hook to the ALDL.

If it were me, this is how I'd start if you're not going to get some hard data on what the car is doing.....


1. Check ALL vacuum lines, especially the hard plastic one's under the plenum....if they are questionable at all , replace 'em......it's CHEAP and easy to do.



2. You can get other brands, or buy the chemicals yourself etc, but for the $ and time, just buy a can of Seafoam from NAPA for like $5 and follow the directions.......you'll be amazed at the difference this makes.....


3. Get ahold of a GM HELMS , not the Chilton, not the Haynes, service manual and follow the instructions and test the pickup coil and the ignition coil. You might also take the module in to be tested.......


4. Ohm the spark plug wires out from end to end......if ANY of 'em read way off from the others, replace 'em. I'll only use Taylor wires, but that's just my preference.



5. Replace the plugs while you're there. AC plugs will cost you all of $10 or so....don't waste your money on the expensive ones.



6. Check for EXHAUST LEAKS.........The only good way to do this is to put the car on stands, or take it into a shop with a lift and go over the ENTIRE exhaust......I found a leaking flange by accident this way.....couldn't be heard really at all until under the car.

Exhaust leaks can make the idle do funny things......


7. Follow the directions on this site.......search for Vader's instructions, they are the most concise....and check / set the timing with a timing light, reset the IAC and the check / reset the TPS........this seems to clear up ALOT of idle problems.



HTH