so i have a 95 blazer. W code motor.it has a speratic miss. all together i have 800 dollars in new parts and it still doesnt run right.
it has new injectors, new distributor, new cap and button, new plugs, new wires,new coil, new cam sensor, new cataletic converter, new intake gasket and new 02 sensors. ive checked the fuel pressure and it is fine.it doesent miss all the time just sometimes and it is very hard to start sometimes. then somedays you turn the key and it fires rite up.ive had mechanics look at it and they cant figure it out.it was reading a miss fire on cylinder 5 before we changed the distributor.now its not showing any codes. can anyone help me?!

 

Have you changed the fuel filter, cleaned (or replaced) the EGR valve, and what prompted you to just change out the parts that you did? You say the fuel pressure is 'fine', do you know what the figures from the tests were?

 

well i changed all that because it was all bad.the distrubuter moved up and down a half inch, the plugs and wires were bad as well as the button,cap, and coil. i dont remember the exact fuel pressure but my mechanic said it was fine.

 

I had a similar problem in my truck and the dealer couldn't duplicate the hard starting. Went to pick it up and it happened right there on the lot. Sometimes the fuel pump can be going bad and at start-up the will be a drop off in fuel pressure.

The best thing to do would be test the fuel fuel pressure when you have a hard start situation (will take two people). This may or may not address the missing problem as well.

 

have you checked your timing chain for excess slack? have you done a compression check?