I have a close friend here, he is a mechanic, helping me a lot. He has his customers 1996 4 door blazer with 4.3 engine ( same as mine) , the engine had fuel ( 60 psi continiously, sill over 55psi after I shot the key), has spark ( coil,module,plugs, cap-rotorchanged), crank-cam and chain is fine , crank position sensor has changed, the car still dont start.

Today we had get sick trucks ecm and pluged to my truck started fine, no failure or lights etc, we had plugged the actron 5000 serries hand held scanner, there no failure code etc, but the truck still didnt start.

BTW battery is fine engine is turning but no start....

fuel is ok, spark is ok, electric is ok, air is free, ecm is fine, what else we shouldcheck?[:-]

Also we have aparted the cat and exhaust while working, theres no chance for plugged cat.

your urgent help will really appreciated..
Thanks.

 

have you checked the starter?

 

yes the starter is fine, engine is rewing with it, battery is fine too, we couldnt find anything logical [>:]

 

Have you done a compression test?

 

Yes compression has tested.

update:
today car has started, the car has previously lpg converted, we had cancelled the lpg option and its fine... previous mechanic has connected the lpg switch to wrong place

thanks for the replies.

 

Well, yeah, that could make a difference.

 

I beleive if the car has produced for gas, convertion is not good. Especially if the guy doesnt know what he is doing.

Actually, before we discover the lpg switch, i was suspicious about, neutral safety or its power supply, but the engine was reving ...

Anyway , finally it started.
Thanks again.