i have a 95 blazer with a 4.3 vortec, vin-w
the engine is running rich. black smoke is coming from exhaust and onto driveway. 12mpg instead of standard 15, smell of gasoline in cab. not as bad since i replaced the fuel filter one week ago. can see some build up of liquid on hoses under the engine.

from reading different threads on this forum i am thinking it is the fpr and/or cfi spider. my question is this- is there a way to tell which one needs to be replaced without opening the plenum? i dont want to take it to the shop to get tested because that will cost $80. if i have to open up the intake manifold i would prefer to do it only the one time for a fix. i think i might be able to replace the fpr myself. i am not confident enough for the spider.

i have read about the fuel pressure tests but i am not sure how to go about this and what is involved.

thank you in advance for your time

 

The fuel pressure test is the way to start. Get yourself a fuel pressure gauge and attach it to the test port located at the back of the intake manifold near the brake booster (driver side rear of the plenum).

If you think you can replace the FPR, the spider is actually easier, IMO.

A word of advice though, if you disconnect the internal fuel lines (commonly referred to as the "nut kit") that run to the spider, they should be replaced. Even moving them around can sometimes cause a leak where the nylon lines are pressed over the fittings on the ends of the lines.

 

thank you for the prompt response.

I think i will take your advice and get a fuel pressure gauge. It sounds like a device that is a must have when owning a blazer.
My reasoning for thinking that i could replace the fpr was the diy article that was posted on this site. That article made it look not easy but at least do-able.
Is it more difficult to replace the cfi with the newer mfi? or is it just the same?
anyway, i will post the results of the fuel pressure test after the holidays.

Thanks