Rough running and missing power

[jft7032]

Folks:

This is my first post to this forum, and I am glad you folks are here. I would appreciate your good help in diagnosing my problem. I am strickly of the "shade-tree mechanic" variety with real specialized mechanical knowledge.

For a couple of months now my '90 S-10 pickup (6-cylinder, 2.8 liter engine, fuel injector) runs increasingly rough; I can still drive around but the problem is becoming more pronounced. When I first start the engine, it will run perfectly smooth for about ten seconds, and then it dips down into a seemingly gas-deprived idle. It may or may not die on me, something it had never done before.

I have changed the fuel filter, plugs and SP wires, air filter and PCV value. (Haven't checked cap and rotor, though.) Poured two bottles of Lucas fuel-injector additive down the tank but still no smoothing out.

What is my next diagnostic step, please?

jft7032

[OverBoardProject]

check the fuel pressure, your pump or fuel regulator might not be up to snuff. Also try to loosen off gas cap just in case it isn't venting properly.

Then check cap and rotor.

[jft7032]

Overboard Project:

Thanks for you suggestions; will do what you advise.

Originally Posted by jft7032

Folks:

This is my first post to this forum, and I am glad you folks are here. I would appreciate your good help in diagnosing my problem. I am strickly of the "shade-tree mechanic" variety with real specialized mechanical knowledge.

For a couple of months now my '90 S-10 pickup (6-cylinder, 2.8 liter engine, fuel injector) runs increasingly rough; I can still drive around but the problem is becoming more pronounced. When I first start the engine, it will run perfectly smooth for about ten seconds, and then it dips down into a seemingly gas-deprived idle. It may or may not die on me, something it had never done before.

I have changed the fuel filter, plugs and SP wires, air filter and PCV value. (Haven't checked cap and rotor, though.) Poured two bottles of Lucas fuel-injector additive down the tank but still no smoothing out.

What is my next diagnostic step, please?

jft7032

[BlazerLT]

Check your timing with the timing wire disconnected from the PCM under the glove box.

http://www.automotiveforums.com/vbul...d.php?t=453371