On my '88, it starts right up and idles fine. However, it tries to die when you give it any throttle. I get around it by driving it like a carbureted car with a non working choke. Once it warms up a little it's fine. Then after it warms up, the idle isn't smooth. A bit of vibration in Drive, much worse in Park.

What do you think is going on?

 

The 'could be' list might get a little long. And you may have more than one fault.

The coolant temp sensor is a prime suspect when cold running problems arise. We can give you the specs if you want to check the resistance. Or just replace it for $25 and 30 minutes time; not too hateful as guesses go.

Idle roughness could be clogged injectors or non-firing injectors....or an ignition misfire. Have the injectors ever been cleaned?

When did it last have new plugs, plug wires, distributor cap, etc?

When is the last time it had a good highway run and/or last time you really poured on the coals? Whenever mine starts running weird I know it's time for 'The Italian Tuneup'. Always runs better after giving her the boot a few times.

What I've mentioned is just the easy stuff. Others will chime in.

Sometimes you just have to dig in, repair faults as you find them, and keep moving along.

Cheers
DD

 

Temp sensor specs would be nice.

Injectors haven't been cleaned in the time I've owned the car (October 2019-No records before that)

I did plugs, wires, and distributor cap some time last year. The old plugs didn't look too bad.

Last good highway run was Monday. I drove it back and forth to work (27 miles each way) several times a week for the last couple of weeks. It runs fine warmed up and under load and pulls pretty hard at WOT.

 

Adding to Dougs list.

Throttle rod adjustment
Throttle body cleanliness
TPS out of range, or getting old a flaky.
Throttle pivot shaft end rubbers are AWOL, or getting that way.

Fuel enrichment valve, assuming your market has one, we call it the Blue White Valve.

Some attachments for beer o'clock reading.

 

Testing the Coolant Temp Sensor

Cheers
DD

 

Turns out the AAV is bad. That's probably not the only thing wrong. More to follow.

 

Welsh has new AAVs in stock. Ordered one last week. Moss has them listed also.