Hey all, I am still having trouble with my blazer. I hook up my fuel pressure tester to the inlet before the fuel filter and i get a constant65-70 psi then it immeadiately bleeds to 20 then 0. while the pump is running it's fine. With the engine on it drops about 8 pounds. I can let the engine idle forever. When I drive it it feels like it's cutting out but the pressure is fine. Staying at abut 58-60. Then the truck dies and will not restart untill it has cooled down. I have replaced the starter, coil pak, wires, plugs, cap, rotor, fuel filter, FPR in the intake, nut kit, catalyatic converter, and oil pump in the last 6 months and the truck still wont make it to the store. The only codes i get are of course the 12. Any ideas of what the next thing to check is? I broke down and took it to a so called mechanic who even with his $4000 dollar scanners looked at me like "I dunno" and straight said it." I dunno". $95 bucks and even the local chevy dealer is stumped. Nice, I got charged to stump a mechanic. Can anyone please, please, please help me out. There is free beer or food or whatever floats your boat.
Thanks in advance,
95Vortec/ Leo

 

I would recommend removing the ignition control module and having it tested. The problem existing after warm up leads me to believe that the ICM may be overheating. Have the folks at your local Advanced or Autozone test it repeatedly to get it nice and hot. The ICM is mounted to a heat sink and requires thermal paste between the two for good thermal transfer.

 

Thanks for the tip boss. I will have it checked at autozone and post on its condition. As for the pump. I know it should hold steady and it dose not. Any ideas? What about the sending units and the possibility that its bad and causing a leak down? Or do the pumps themselves need replacement when there is a leakdown at the tank? I know the truck was decently maintained when i got it but everything is still the original parts. Just changed the motor mounts and saw the original barcodes on em. The truck has about 289000 and I would bet that its all factory in the tank still. Thanks so much for the potential ICM save. Way cheaper and simple to change.

Thanks and will post my results.
Leo

 

wow, 95 whenever i have an issue ill make sure and pm you. seems like you know the 95 through and through..

 

klote82, the preferred method is to keep everything on the forums simply to benefit everyone. If you have a question, simply post it and everyone, including 95vortec can help with it. Thanks!

 

I got some results finaly. The guy at autozone tested the ICM and said it passed. I read in many posts here ( through the helpful search option ) to have them test and test it to get it hot. He swore one test would do it but tested it 5 times for me while i was present and it passed every time. I have also read that the pump heats up and will become sluggish or not deliver enough pressure. I will drop the tank next to do the tests more efficently since I am a novice mechanic. So onto the next question, should the sending unit be replaced aswell? Is it worth the rebuild or get it new?


Klote82
AnythingI might be able to help with just let me know. I would say one of these other guys would still have the best general knoledge of your situations and should be consulted first. Also the search here is awesome. Be sure to mess with it.
95Vortec


Sorry for the long delays as I lost my PC to the ex.

Thanks again,
95Vortec

EDIT: Dielectric or silicon between the ICM and the distributer?