I have a 95 S10 4.3 Central port injected blazer that died on me while driving. I have replaced about everything and it still wont start. I replaced: 1. rotor 2. cap 3. plugs 4. wires 5. fuel pump 6. FPR was leaking so I replaced that 7. fuel filter. I am still getting insufficient pressure at the test port (jumps to around 60 then slowly falls to about 52). The only thing I can think of is that the CPI isnt opening to let fuel into the lines to the injectors. How can I test for this before going out and spending $350 on a whole new CPI? If anyone can tell me how to test for this or has any other helpful ideas lemme know PLEASE! Oh yeah I almost forgot to mention I am getting plenty of spark and I can hear my fuel pump whine up fine and all my dash lights are working fine.

remove the upper plenum and check for washed areas (the whole area should be dirty if there are no leaks). also, is ur check engine light on? there are many threads on the cpi. check the FAQ thread for links or do a search.

could be a crank sencer

I asume you have good spark to plugs.
Will it run on carb cleaner?
Are you getting injector pulse?
Check on a scanner or check at the 2 wires going into front of plenum and also for 12 volt power to the injector.
MT

I asume you have good spark to plugs.
Will it run on carb cleaner?
Are you getting injector pulse?
Check on a scanner or check at the 2 wires going into front of plenum and also for 12 volt power to the injector.
MT

I have good spark to the plugs. Also, I did pull the plenum and there was washing on the passenger side so I replaced the fuel pressure regulator. There was a tiny bit of washing on the driver side (85% still black so I didnt replace the nut kit). I will try and check the wires to the injector.

remove the upper plenum and check for washed areas (the whole area should be dirty if there are no leaks). also, is ur check engine light on? there are many threads on the cpi. check the FAQ thread for links or do a search.

i cant get the car to start so my check engine light is on whenh the key is on auxillary. Isnt it always suppost to be on untill the engine is running?

You sure you are getting plenty of spark?

Sounds like a failed coil.

i cant get the car to start so my check engine light is on whenh the key is on auxillary. Isnt it always suppost to be on untill the engine is running?

Bingo :grinyes:
Yes the check engine light should be on when key is on engine off.
If not it points to a computer or key on eng off power feed problem.
Like said double check that spark to plugs when cranking. Should be good hot blue spark to plugs. Then if you have spark check for full fuel pressure, Then if spark and fuel move on up to a Check for injector pulse.
MT

It is strange the check eng light is on on auxillary and not on with key on.
Does it come on on engine crank?
Check the fuse and ign on power feeds to the computer.
Which computer do you have a PCM or VCM.
Like is the computer on right fender apron under water tank or under dash?
Let me know whick one and I can post the wiring for it.
MT