Truck intermittently loses power while driving

BUTCH PEARSON

MEMBER
1988 CHEVROLET CHEYENNE
5.0L
V8
2WD
AUTOMATIC
150,000 MILES

The truck always starts, sometimes it runs perfectly after starting but at any moment can lose what appears to be about half of its power. When pressing on the gas pedal at this point it seems to do no good the engine just sort of boogs. The vehicle will not go faster but you can maintain whatever speed you were at sometimes the vehicle will run fine all day, sometimes it will do the sporadic bogging, cutting out constantly. If it dies at an intersection while it bogging, it starts right up with the turn of the key. Sometimes running smoothly for a while other time starts the bogging immediately upon start up. I have replaced... Plug wires, cap and rotor ignition module electronic pick up on the distributor none of which has made a difference. Please help

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

What you described sounds like it could be related to a fuel pressure issue. We should check the pressure to see if it is low. However, before that, check to see if there are any diagnostic trouble codes that may help us determine the problem.

This vehicle has an OBD1 computer system. You don't need a scan tool to retrieve codes. All that's needed is a shift jumper wire or even a paper clip.

Follow the directions in this link and let me know if you find codes and what they are.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

If there are no codes, then check fuel pressure. Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

One last question. By any chance do you hear any rattling noises from the exhaust system? The internal part of the catalytic converter may have come loose and causing a blockage of exhaust on and off. That will certainly cause power loss.

Let me know what you find or if you have other questions.

Take care,

Joe

See pic below for the manufacturer's fuel pressure specifications.

Image (Click to make bigger)