88 Tbird 3.8 cold running

[gt427]

My wife's Bird lately runs badly until normal operating temp is reached. It has EEC-IV and fuel injection.

At start up it runs @ 1500 rpm for 20-30 seconds - which is normal. As the system backs down the rpms it begins to cough, sputter and die, so the computer cranks up the rpm. This up and down process repeats until temp reaches near normal. Then everything is fine.

If I try to run the car during this process, it'll sputter & usually die. and continues to run badly even after normal temp is reached. The only way to get it to run right is to let it idle up to full temp.

I do not get any codes, all 11's.

2nd issue - in the last 2 days, while the engine is on, I get a loud "beep" from under the dash or maybe kick panel on the passenger side. Every 60 seconds. I know the ECU is in the kick panel, but I'm not aware it can emit any sounds.

Any thoughts?

[mobil_12]

Sorry, I cant help you on the noise from the kick panel....

Usually whe you have a car that wont run well until op temp is reached, suspect the computers temp sensor. If the sensor is bad the comp will substitue a set value for the temp. This will cause all kinds of drivability problems, from injector pulse to timing adjustments. Check it out first. After all, they are cheap and easy to fix.

[gt427]

Originally Posted by mobil_12

Sorry, I cant help you on the noise from the kick panel....

Usually whe you have a car that wont run well until op temp is reached, suspect the computers temp sensor. If the sensor is bad the comp will substitue a set value for the temp. This will cause all kinds of drivability problems, from injector pulse to timing adjustments. Check it out first. After all, they are cheap and easy to fix.

Yeah, suspected temp sensors. I did check resistance on both the coolant temp sensor and air charge temp sensor. They are both within tolerances at cold and hot ranges. Are you suggesting I replace them anyway? I know $13 each is cheap, but it seems like a waste if they're not the problem.

Do you know of a way to check the connectors for those items?

That beeping is driving me nuts. I guess I'll start taking apart panels until I find the source!

[Jim Adams]

I have an 89 Tbird supercoupe and right behind the glove box is an optional control module for performance I suspect cause not all Tbirds and Cougars have this ,,sometimes it beeps when engine is cold and I am throttling her up on the freeway,,but it hasnt done it since winter time,,,Did you try to change your thermostat,,it might be stuck open,,and the car isnt warming up at all till she gets good and hot..

[mobil_12]

If your temp sensor is within specs then it is PROBABLY good. Ive been smoked on that before.

Something Ive run into lately is fuel injectors that are sticking at cold start up. They wont work untill they warm up, then work just fine.

Try doing a cylinder balance test. Start the car when its running poorly and pull off a spark plug wire one at a time on each cylinder. The cylinder that doesnt drop the idle is your problem cylinder.

After that, check for spark, fuel, compression, etc. All and engine needs! Four cycle engnine = Suck, squeeze, bang, blow.

[gt427]

Balance test didn't reveal a probelm with a cylinder. One of the guys at the local parts house suggested I clean out the Throtle Air Bypass valve. Bingo! Apparently it was stuck.

That beeping seems to be associated with the battery/charging system. It may have a dead cell. Every time it beeps, the display on the dash switches to battery condition and the little battery icon flashes. So that's next.

"Suck, squeeze, bang blow"? Hey, I thought that wasn't allowed on these forums. :-)

[gt427]

Originally Posted by Jim Adams

I have an 89 Tbird supercoupe and right behind the glove box is an optional control module for performance ,,,Did you try to change your thermostat,,it might be stuck open,,and the car isnt warming up at all till she gets good and hot..

If THIS car has a performance module, believe me, I'd love to find it! Maybe then it would get out of its own way! The only "performance" item on this car is the TurboCoupe steering wheel (well, the K&N filter qualifies, I guess).

I tried the thermostat first, but it was working properly.