OK i've posted a couple times on here before about my truck and still have yet to find a solution. Im gona start from the begining and describe everything that has been done and what has happened. I'd like to offer a $50 reward for who ever can guide me to a solution, ill send the $50 through paypal.

Specs: 2001 Chevy Blazer 4.3L Vortec
4x4 "LS" model

200k miles

"W" VIN engine code

When I bought it originally, it would run rough but it would get up to about 30 mph, if I tried to get it to go any faster it would act like it wanted to stall and back fire really bad. It had a few codes. Crank Sensor code, Cams Sensor code, a Coolant temp code, and a Crank/Cam Corelation Code

I started by replacing the Crankshaft position sensor.
That didn't work, in fact since i did that i cant get it to run like it did anymore.

Then someone told me it may be the fuel pressure regulator, so i tried that and still had the same problem.

I then looked at my Chiltons and decided to replace the ICM and ignition coil. That didn't solve anything either.
The plugs and wires are good and I have spark.

I then gave up and towed it to chevy where they put a new computer in it. That didnt do anything to help because the tech needed it to at least start up to get the crank and cam corelated. But by spending two hours on it swapping distributors and trying to retime it he came to the conclusion that the timing chain may be the problem.

The engine was then taken apart, the timing chain checked out ok, i even took all of the push rods out and the lifters just to check them out. The camshaft was then taken out to inspect the lobes and the teeth on the gear. No problems there. The only problem we spotted was that the thrust bearing did have some play in it. But the mechanic at chevy said that, the play wouldn't be enough to affect the crankshaft sensor from sensing the position of the crank.

When the truck is timed set at TDC with the distributor in the correct way. The engine wants to backfire out the intake. It also backfires out the exhaust. The engine turns over, but it sounds like a cylinder fires at the wrong time and wants to push the engine backwards, which completely stops the engine and just sounds bad when it happens, its probably hurting my starter.

So now im at the point where i have no other ideas. Somehow the ignition system is messed up, and is not firing at the right time.

I have also taken out the main engine wire harness to test all of the connections going to the PCM, added a little electrical grease, that didnt solve anything either.

If you have any questions please ask and i will reply assap.

 

sounds like it could be 180 degrees out of time now. when they did the timing and brought it to TDC did they bring it up on the compression stroke or the exhaust stroke?

 

That would be my guess too Biohazed.

 

x3 on the timing, even though it had spark did it have enough mine died on me recently completely and would not start It had what I thought was plenty of spark but it was discovered that the coil lead was bad it was corroded and not allowing enough current to the dizzy even though we got a good spark about an 1/2 inch long from plug to block when checking

 

Check out the EDI engine timing thread in the Tech Article (DIY) section.

 

heres a easy way to check your timing , note where you #1 sprake plug wire enters your dist cap then remove the cap and the #1 sprake plug put your thumb over the spark plug hole and have someone crank over the truck when the cylinder compression pushs your thumb away the rotor should be pointing at the spot where the #1 wire enters the cap, if not its out of time

 

wayyy outta time, have an old school mechanic time it

 

I know you said the plug wires were good but I had a car I took to a mechanic and he was supposed to do a tuneup , he cut corners and did not replace the plug wires it did just what you are saying . go out at dark and check to see if you can see spark grounding from a wire, may have to moive them around

 

sound exactly like what my 02 zr2 did. it was the gear on the bottom of the distributor. whoever worked on it may have overlooked this,

 

The distributor is definatly not installed right and the plug wires cannot touch anything or will missfire and must use platnium plugs or will missfire and if the distributor cap doesn't have brass contacts you have another problem coming there