Blazer just died on the road. Towed it home..have replaced the fuel pump,fuel sending unit,fuel relay switch,ignition module,distributor cap and rotor still nothing. We poored some fuel in the tube up top on the front of the engine( sorry I can"t for the life of me remember what thats called) and it started right up but only ran until that little amount of fuel ran out.
The fuel fileter was replaced a month ago..

The pump definetly comes on ,but seems like the fuel is not reaching it destination. Could it be the fuel injector? Or are we mising something else? We have been trying to fix this for 2 weeks now and are getting very frustrated..
Could someone please help us out with this?

Thank you so very much.

Heather

 

If adding fuel made it run-albeit for a short period of time, it's quite likely fuel related. You'll need to put a pressure gauge on it-many links/threads about this on this site. Let us know what reading you get and we'll advise.jp[&:]

 

Okay, pressure is at 18 psi. We drained the line about 3 times and still no start. There doesn't seem to be much fuel at all in the return line. We took that line off from the back of the engine and there was very little fuelthere. It's makeing sense that the fuel is reaching thefuel rail area but not going much futher to get things started. Could the fuel injectors be the problem? Please help if you can...
Thanks a ton.
Heather

 

If this is a CPI motor (and I think it is), then 18psi is no where near enough pressure to run the engine. You need at least 55 psi. I would check the power and ground at the pump before dismissing it as a faulty replacement pump.

If it is the pump, replace it with an AC Delco if you do not already have one.

 

Not sure on the CPI.. What is the CMFI? We just replaced the damn pump twice thinking this was the culprit. Are we just getting cheap aftermarket pumps that won't do the job,you think?
So 55 psi is where we need to be??

 

If your throttle body points forward, you have CPI. I do not think that the TBI motor was available in the '94 Blazer...

It is quite possible, but like I said, make sure you have good ground and power before you replace it again.

 

do all blazer fail in same time lol??? im bring mine in the garage sometimes this week! i feel your pain!

to the mods:
any link to show how taking fuel pressure and what instrument to use?

 

CPI = CMFI

It's technically Central Multi-Port Fuel Injection, just different acronyms for the same thing.

 

also could be the plastic fuel lines in the plenum (also known as the nut kit) could be split and leaking badly.
to check this take the upper plenum off and turn the key to the on position. fuel will squirt out if it leaks and u will be able to see it.

 

bottom line-8th digit of the vin 'w' or 'z'?? That's the big question-if you got a 'w', you also have WAY too low fuel pressure(for some reason).jp PS if you got a 'z', then it's back to the drawing board cause 18 is in the ballpark.[:'(]