TBI low idle

[LB2387]

I have a 1987 chevy r10 with a 350. When I crank it up on a cold day, it will start but idle just high enough to stay running (probably around 300 rpm) and will sometimes stall and give a poof of smoke out the top of the throttle body. When it does stay running, i can disconnect and reconnect the CTS and everything will go back to normal. I replaced the CTS and everything was good for a couple days, but it has started doing the low idle thing again. I can still correct it by messing with the connector but there doesnt seem to be any damage to the pigtail. No loose wires or corrosion or anything like that. COuld this be a possible ECM problem?

 

[shortboxchevy77]

Best way to know for sure is to use a scan tool with live data ability to see what the ECM is seeing as far as the coolant temp is concerned. If it is maxed out at -40 that means bad sensor or lost connection. Another thing to try is using a small pick and bending the contact tabs back up inside your pigtail connector. Over time they can get bent down too far causing intermittent contact.

 

[bucket]

Have you checked for slop in the throttle shaft? If the shaft moves around in the TB, it can cause inconsistent vacuum leaks and the ECM will have a hard time keeping the idle where it needs to be.

 

[89Suburban]

Excuse my ignorance but what is a CTS?

 

[bucket]

Coolant Temp Sensor

 

[Alexandr-Rychok]

The headlight dimming w/ the signals may be a short - time to check wires and connections.

What do you mean low power at idle?

Gary

 

[89Suburban]

The headlight dimming w/ the signals may be a short - time to check wires and connections.

What do you mean low power at idle?

Gary

Headlights have noting to do with this topic.