Engine dies when i let off the gas??

[klwebb]

Ive got a 1971 c10 w a 350 thats not doing so hot. it will start up after a few tries (normal) and sounds great when im on the gas, but when i let off the gas to get it to idle, it will idle for a little bit and then die on me? any idea what it could be? once i get this issue fixed ill be able to take it to hopefully pass emissions and get it registered. read more about the truck on my build thread. thank you!!

[GTSideSwipe]

Originally Posted by klwebb

Ive got a 1971 c10 w a 350 thats not doing so hot. it will start up after a few tries (normal) and sounds great when im on the gas, but when i let off the gas to get it to idle, it will idle for a little bit and then die on me? any idea what it could be? once i get this issue fixed ill be able to take it to hopefully pass emissions and get it registered. read more about the truck on my build thread. thank you!!

Sounds like your idle speed my be to low. Do you know what it is idling at? And I'm presuming this is while in neutral?

[FlameOut]

Like stated above, idle set to low, or maybe a vacuum leak

[davepl]

Time for basic tuneup and troubleshooting, I think.

If turning up the idle speed doesn't work, then it's back to basics:

- Check for vacuum leaks
- Check base timing
- Check mixture screws
- Check that each cylinder is firing

If the mixture screws don't seem to work, then you have low speed through the carb.

If you have vacuum at the vacuum advance port, your idle is too high, or at least the throttle blades are open too far.

Both of these latter things could be vacuum leaks too.

[swamp rat]

The other possibility is your idle circuit is all gummed up from this crap gas we have.

Here's a trick I have had work for me:

Get a can of carb cleaner and have the red straw attached, now take a screwdriver and turn the air/fuel adjust screw in until it lightly seats while doing this count the turns in so you can reposition it later, now take the screw all the way out and don't drop the spring.. and take the carb cleaner and stick the red straw all the way down and hold it firmly against the bottom, watch your eyes (safety glasses) and give the can a couple squirts of carb cleaner while looking down the throat of the carb and see if you can see carb cleaner spraying into the ventury, if not its plugged, if you have 2 air fuel screws repeat the process in the other port.

[hamjet]

Originally Posted by swamp rat

The other possibility is your idle circuit is all gummed up from this crap gas we have.

Here's a trick I have had work for me:

Get a can of carb cleaner and have the red straw attached, now take a screwdriver and turn the air/fuel adjust screw in until it lightly seats while doing this count the turns in so you can reposition it later, now take the screw all the way out and don't drop the spring.. and take the carb cleaner and stick the red straw all the way down and hold it firmly against the bottom, watch your eyes (safety glasses) and give the can a couple squirts of carb cleaner while looking down the throat of the carb and see if you can see carb cleaner spraying into the ventury, if not its plugged, if you have 2 air fuel screws repeat the process in the other port.

X2 on the idle circuit..