Timing/vaccuum issue?

[98_k1500]

The black smoke is from a over fuel issue, My first suggestion would be to put a paperclip in the plug for the coolant temp sensor in the intake. That will make it show the computer that the engine is at operating temperature and will rule it out if it makes no difference. I don't think you have a timing issue, I think its just flooding it to the point it backfires and won't run. I had one doing this so bad it would backfire and the tb would stay on fire until you put it out with something. Coolant temp was bad. They can read all the way down to -40° if they are bad, and make it think it needs WAY more fuel than it actually needs. do that and see what you find out.

 

[cjman250]

The black smoke is from a over fuel issue, My first suggestion would be to put a paperclip in the plug for the coolant temp sensor in the intake. That will make it show the computer that the engine is at operating temperature and will rule it out if it makes no difference. I don't think you have a timing issue, I think its just flooding it to the point it backfires and won't run. I had one doing this so bad it would backfire and the tb would stay on fire until you put it out with something. Coolant temp was bad. They can read all the way down to -40° if they are bad, and make it think it needs WAY more fuel than it actually needs. do that and see what you find out.

where would you put it in the sensor to test this?

 

[98_k1500]

Unplug the sensor and bend the paperclip in a U shape and stick it inside the plug (the side with the wires in it) so it directly connects the 2 wires. This will make it think the engine is warm.

 

[cjman250]

sorry to thread jack, but do you think it could be the coolant sensor if it bogs down when the engine is cold, mines been doing it forever

 

[98_k1500]

Quite possibly, i drove mine for a month with a paperclip in it before i finally fixed it. It seemed to run fine with that done. It may be a little cold natured for a min if its cold outside like that.

 

[cjman250]

ill have to try that

 

[93Chevy_1500]

I only have a backfiring problem when the engine is under a load or i put my foot in it to pass or something. But i can sit in park and rev it all day and not get a back fire from it.

 

[98_k1500]

It definately sounds like a fuel issue to me. See about jumping out that coolant temp sensor and see if it helps anything. After that, i would be looking at testing the TPS and the MAP.