I have a 94 gmc jimmy cpi w vin with just over 170k.I recently had a fpr

leak and with the help of this forum was able to fix the problem.It wasnt

100% after that since i had a cloged cat i fixed with a "test pipe".I'm

haveing an issue now that doesnt allow allow me to get any

throttle/rpm's from the motor but starts cold and idles fine till it gets

warmed up and eventually wont start at all. at times i hear the fuel pump

sound last twice as long as usual.When i tested my fuel pressure it goes

up to 55psi when i turn the key forward and the pump comes on.When

the pump stops whiring my pressure drops to 15 psi as fast as it shot up

to 55.i get the pressure back to 55 when i crank it over and it holds at

48-50 psi at steady idle.When i try to give it gas it bogs really bad,spiting

and sputtering.On the pressure gauge it flutters then between 55-65 psi

rapidly like the gauge is on smack.i've read up that i should be holding

that higher psi with the key forward and engine not running.I tried another

fpr yesterday thinking it could have been a bad or weak one.While i was in

the intake i pulled each poppet and used my remote start to see if they

all spray and they did.I noticed the #1 cylinder poppet didnt spray the

first try but tried again and i did get the 2 short bursts i got on the other

5.Im debating now on just replacing the fuel pump or the entire spider

im told there both new from a prior owner within the last year/15k miles.

i always read up on prior posts and problems that are similar to mine but

just cant what my best bet would be on this.I haven't checked the fuel

pump relay yet but plan to before i spend the money on these more

pricey parts.Ty in advance for any input im new to these forums and have found great help already here without even posting an issue,till now lol.

 

Sounds like you still have a problem with the fpr since it's not holding pressure. Maybe a leaky poppet nozzle.

 

I'm sure you've probably checked the incoming fuel line "nut kit" but mine had a hairline crack that was giving me the same problem. I took my plenum off, then after turning the key I wiggled the fuel line and found it. Also, when I had the plenum off I took the fuel line off the spider and connected a longer piece of hose to it, then blew through it to see if it was clogged.

 

Ty for the tip,after a new fuel pump i was holding good pressure but still wouldnt run right.I replaced the spider injector and nut kit but the t-30 on the back of the intake manifold(lower)was stripped...I worked on it for a few hours then said screw this.I took off the lower intake then and im kinda glad i did.I had a very clogged port i'm wondering if its the egr passage?I took some pics with my phone of what it looks like under there.
after cleaning it all up and changing the oil it runs great.I had some spill over so dont over look the oil! had anti freeze in it.


after i cleaned it up

this article helps understand the cpi and how it works

http://www.tomorrowstechnician.com/A...injection.aspx