350 TBI runs poorly only when cold
 

1987 -TBI runs poorly only when cold as soon as it warms up it seeems to be fine. Coolant temp sensor????
With no scanner how do i get te codes again- it's been a while. Jumper between A & B is it??? and count the blinks.

Re: 350 TBI runs poorly only when cold
 

http://www.troublecodes.net/GM/ Good site with directions and code meanings...when my CTS went I had the opposite problem, ran great when cold and horrible when warm.

Good luck,
Mike

Re: 350 TBI runs poorly only when cold
 

The cts may not set a code. But for $10 or so it probably needs a new one anyway. Many faulty ones will act just as yours does Crossy..

Re: 350 TBI runs poorly only when cold
 

grab a dvom and a wiring diagram, then test the signal wire, when cold it should be around .5-.6v if it reads like 3.0v or more when cold its out
ryan

Re: 350 TBI runs poorly only when cold
 

signal wire to the CTS??? and those numbers are with the key in the 'on' position or running?, this is the first day i have off since everyone replied and i'll have a chance later today to check things. thanx . DAVE

Re: 350 TBI runs poorly only when cold
 

I had the exact same problem with my Tahoe running very crappy when cold, but fine when warm. Spent a LOT of time and money replacing pretty much any possible sensor etc. that could be at fault.. Turned out to be bad injectors. 15 minutes to replace and it ran like a charm!
There is a thread here somewhere about the problems I had and what I had tried to do to fix it.

;)
Ken

Re: 350 TBI runs poorly only when cold
 

Could also be the air temp sensor... I have to agree codes may not be in there.... Digital volt meter is the best way to go! Of course it may take hours to find a faulty sensor if one is to blame, but at the price of some of the sensors it may be worth the time!

Re: 350 TBI runs poorly only when cold
 

Ken, my CHECK ENGINE light is staying on all the time though- was yours?? thanx , DAVE

Re: 350 TBI runs poorly only when cold
 

Oh ok. No, mine was never on. It just ran real bad and smoked black.

;)
Ken

Re: 350 TBI runs poorly only when cold
 

code 15 for the CTS does come up. I'll get one and see if it cures it. DAVE

Re: 350 TBI runs poorly only when cold
 

If it is not your CTS, i would check and make sure your O2 sensor is plugged in and not bad. will help you out with checking to see if your O2 sensor is the cause of your problem. Hope you get your problem fixed.

Re: 350 TBI runs poorly only when cold
 

www.cfm-tech.com sorry it didnt show up

Re: 350 TBI runs poorly only when cold
 

GOOD= Replaced the CTS and it runs fine now when cold - light went off after resetting- Schweet.
BAD= truck will not start without tapping the gas pedal now= WTFIGOH ??????
DAVE