Mechanics

CHEVY CHEVY TRUCK POOR ENGINE PERFORMANCE

1992 Chevrolet Silverado

Engine Performance problem
1992 Chevy Silverado V8 Four Wheel Drive Automatic 148000 miles

Conditions:
Engine was replaced at 71,000 by dealer. Truck is now at 148,000. Slowly been getting worse for 1 year.

Problem:
Truck starts but then while driving it, oil pressure slowly goes to approx 15 psi. Truck runs rough at all speeds and there is a consistent overall lack of power.

It will sometimes stall pulling up to a stop sign. When the engine start to stall, it stutters and oil pressure and other guages drop to low levels. Pressing on the gas will save the engine from stalling.

I am not sure but I had engine work done by what I am now thinking is a incompetent mechanic. They replaced the distributor shaft, rotor, and cap, etc.
Avatar
Red_one
August 4, 2010.



Was it doing this before the tune up? Has the check engine light come on or have you checked fuel pump pressure? Final two things. Have you checked for any vacuum leaks and has the catalytic converter been checked to see if it is plugging?

Let me know.
Joe

Hello Joe,

It was losing power slightly. The check engine light comes on frequently. The previous owner had the exhaust dualled off and the catalytic convertor removed. I did not catch that little fact and even more of a bummer the mechanic that I had look at the truck before I bought it did not.

The fuel pump failed and was replaced with an OEM fuel pump four months before the Distributor shaft.

So, in short: SEPT 2008 - New Fuel pump, Transfer case OH kit

JAN 2009 - Remanufactured Distributor, Tune up, Distributor, Cap, Rotor, Ignition Wires, Oxygen Sensor, EGR Valve, and 4x4 actuator

The truck never ran the same. It went downhill slowly though and by the time that I figured out something was really wrong, the mechanic had gone out of business never to be found again.

I have not checked any vacuum leaks. My Dad is going to check the timing next week. He is also going to see if " the distributor shaft is lifting the rotor and striking the cap causing mechanical damage". He says that sometime happens.

My uncle who is an actual mechanic says it is probably worn main journal bearings not allowing the oil to come up to full pressure.

Tiny
Red_one
Aug 6, 2010.
I have to agree with your uncle for the oil pressure. As far as the distributor, it's worth checking as well as the timing. Let me know what you find.

Joe