My 1989 firebird starts to bog down when I start it in the morning but as soon as it warms up it runs fine. What could be the problem?

 

Can you read live data from the ECM? If your really want to find the answer, you'll need to have this ability.

GD

 

If I was going to just shotgun some parts at it, the first one would be, the coolant temp sensor.

 

Seconded, but I have severe aversions to deploying the parts cannon without some level of testing. At least test the thing with a DMM. Should be high resistance when cold, and low when hot. Check this thread:

https://www.thirdgen.org/forums/elec...lant-temp.html

FWIW, the last one of these I had fail on a V6 Camaro - it wouldn't run when hot. That was the actual sensor that failed though - if the wiring were at fault (corrosion, etc) then it would likely tend to run when cold and not when hot.

This is pure speculation. Without checking live data and/or testing it manually (which still doesn't verify the wiring unless you also test that), there's no way for us to know what's wrong with the car via the internet with a one sentence description of the problem.

GD

 

Does the v6 have a MAF? Ran into that with my LS1 swap. Everything was checking out. Didn't make any sense to me that the MAF would be an issue on a cold start but it was. On the LS1 I tested it by unplugging the MAF so it defaulted to the fuel tables and it ran fine. Put in a new one and it ran fine.

Not sure if the 89 computer will default to the fuel tables if you unplug your MAF (like the 2k ls1 computer does) -- worth a try though. Just unplug it and start the car and see if it still bogs.

 

I don't know, sounds pretty normal to me? I have an 89 also, but it's a 305 TBI and when first started after sitting for more than 6 hours it's idling high and if I try to take off in it immediately, it slams in to reverse or drive hard, jerking the car and doesn't want to accelerate well. However, if I patiently wait until it automatically idles down, it goes in to gear smooth and runs just fine. Been doing this since I've owned it. You have to let these old cars warm up a little bit!

 

Not if their tuned up properly. My 86 Trans Am runs great at all temps. Immediately on cold start.

GD