Please help with '93 Vortec Blazer

Any help to solve the problem with my Blazer will be greatly appreciated. Here's the story. I have a 1993 4Dr. S10 Blazer 4.3L Vortec , VIN code "W", with only 74,000 original miles on it. It was running rough and had NO power a while back since it had never had a tune-up. I did a tune-up on it (which included a new O2 sensor, plugs, wires, rotor and cap). I also put new exhaust on it which I had wanted to do for a long time. I chopped the cat off of it (opps :-) and put 2.5" exhaust all the way back with a Hooker Racing muffler. It sounds very nice, but it still ran a little rough and had NO power. So, I replaced the MAP sensor, which I had conflicting reports from 2 different parts stores on which one to use, and I replaced the throttle position sensor. Still no power. I know these engines have a lot of power. I had one just like it before, and this thing will hardly climb any hill, not to mention it takes all day to get up to speed on the highway. It has no power at all but it runs and idles great. I also had someone run a computer scan on it and everything checked out fine. It was also suggested that I reset the computer by disconnecting the battery over night, which I did for apparently no reason... does anyone have any idea what could be wrong? I'm completely lost, I don't know what to do next and I just want my Blazer to be normal again..

*~*~*~*~*~*~*~*~*~*~*~*~*~* Andrew James -or- "John " ICQ# 1577147 MSN: snipped-for-privacy@willapabay.org AIM: semajwerdnah *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* "Did you know that Pacific County is flat? If you get too close to the edge my might fall off" - Heather, in reference to the narrowmindednesss of Pacific County, WA. *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Reply to
Andrew James
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1) Check ignition timing. 2) Check compression.

Doc

Reply to
"Doc"

Have you replaced the fuel filter? Check the air filter?

Reply to
WBucha

The compression is good and so is the timing.

Reply to
Andrew James

I took the EGR valve off today to inspect it.. It was pretty clean with no carbon lodged in it.. The little value thing moved very eaisly.. can I rule this out as my problem? they are expensive and I'd rather not replace it unless i know it's faulty. thanx

Reply to
Andrew James

If you are getting black smoke on start up suggest checking the central port injector for leaks. You can remove the Intake Manifold Tuning valve in the middle of the upper manifold and look inside wetness. It's the only thing with wires to it. A couple years ago my 95 S10 PU wouldn't run above 3000 rpm. Fine up to that point. Turned out to be a relatively new fuel filter plugged. In that light these engines like to have a fuel pressure of something like 54 psi. Have you checked it?

Reply to
DonW

one question

do you know that timing is set correctly ?

and yes, rule out the EGR, for now

appreciated.

Reply to
TranSurgeon

I have very clean exhaust from this thing.. no smoke. I have not checked the fuel filter. that is todays project.

Reply to
Andrew James

When the conputer scan was run on it, it said the timing was correct? Is that soemthign I can rely on or does it need to be check some other way?

Reply to
Andrew James

Hope you never get caught without that converter on it. BIG fines for violating Federal laws.

Check the base timing? Timing advancing OK? Low fuel pressure (plugged filter, pump going bad)? Timing chain stretched? Oh and 2.5 is a LOT larger than you should run for pipe on that engine if you want any low end power.

2 inch would be much better.
Reply to
Steve W.

I have recently taken my blazer to someone else to figure out what's wrong with it. the guy has a few ideas but not certain what the problem is yet. Hopefully he will figure it out soon. I will amke another post when we figure it out.

Reply to
Andrew James

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