1992 Chevrolet Other Chevy P30

TRIUMBRA

MEMBER
1992 CHEVROLET
3.5L
2WD
AUTOMATIC
114,000 MILES

Hl: I just bought a food truck that is a customized 1992 Chevy P30. We're having trouble with a surging idle, running rich and dying. Do you have a service person who can help us with it?We've replaced the alternator, idle air sensor, map sensor, emission sensor, rebuilt the carburetor, computer, temp sensor. We just can't figure this out and can't get it to run enough to get it to the shop.

3 Replies

HMAC300

MECHANIC
48,601 POSTS

Scan for codes and check fuel pressure with a gauge. If tbi should be 9-11 psi key on. Check vacuum hoses for being soft and sucking together especially to map sensor. Check to see if canister purge solenoid is open it shouldn't be there will be one line that is vacuum try to put a screw in it to bloc an see if truck will run. If it does then solenoid is bad. It has a red connector normally on passenger sideframe

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Tuesday, April 28th, 2015 AT 12:07 PM

TRIUMBRA

MEMBER
2 POSTS

Thank you. We've checked all of these, which seem fine. We're now looking to replace the EGR, other than that, we still can't figure this out.

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Tuesday, April 28th, 2015 AT 8:30 PM

HMAC300

MECHANIC
48,601 POSTS

Like I said try the canister purge solenoid it's a red connector usually onframe by engine pass side. Block off the vacuum side and see if it straightens out. If it does replace the solenoid. That is supposed to activate at 30 mph not at idle. Also eger may be partially plugged so look for that as well as passages.

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Wednesday, April 29th, 2015 AT 7:09 AM