engine troubles

[bonesaw118]

yeah i'm new to this whole forum stuff but....i just bought a 91 k5 with a stock 350 in great condition....anyways its been running fine until the other day just lost tons of power at full throttle.....it has more power at half throttle than full throttle. anyways i figured it was a fuel problem so i replaced the fuel filter and it was almost completely clogged but it didn't really change anything...and now its even worse. when i start it and put it in gear it dies...i have to keep the rpms up in order to put it in gear. i checked the timing and it was 20 degrees advanced for some reason and when i tried to put it back to 10 degrees advanced it died on me. i checked the spark plugs the cap and rotor. the check engine light isn't coming on either so its not setting any codes....
do you guys have any clue what it could be?

 

[ryoken]

sounds like ya got crud up in the injectors.. And you need to disconnect the est wire for timing it..

 

[4X4HIGH]

Sounds to me like a bad fuel pump, i had very similiar symptoms when my pump was dying on me.

Also as was already stated you must disconnect the EST wire before you attempt to time this vehicle. It is located near the brake booster and is a single tan wire connector.

 

[bonesaw118]

well i bought the complete rebuild kit for the tbi and checked the injectors. the injectors did look a little clogged but not to bad. it did run a little smoother but its still doing the same stuff. i started looking stuff up in the book i had for it and it said it could be the egr solenoid switch. i did a vaccum check on the egr valve and it wasn't working right so i think hopefully it might be that. then another part said that it could be the fuel pump.
do yall know anyway to check the fuel pump? i guess a fuel pressure guage?? or something along those lines.

 

[btolenti]

are you getting a check engine light? Have you checked for possible codes?

This problem could be a lot of different things. Your best bet is to check for codes first before throwing money at the problem.

you need to jump terminals "A" and "B" on your diagnostic connector:

it should look like this:

F E D C B A
G H

Once you've got them jumpered, turn the ignition to "on", and watch the check engine light - it will flash code "12" three times, then any stored codes.

 

[Chevy305]

plugged cat?

 

[4X4HIGH]

You cannot check the EGR on these year trucks since they are reverse back pressure types. If it were the EGR solenoid or the EGR itself it would pull a code 32. I still say fuel pump, this would not pull a code and was the problem i had with mine with your exact symptoms.

 

[Chaddy]

Could be your IAC modual

 

[bonesaw118]

well i went and got a new fuel pump and the little sock thing to go with it. taking out the gas tank sucked but wasn't as bad as i thought it would be. there was tons of dirt and rock everywhere up there. anyways i took the fuel pump out and the little sock/strainer thing was all messed up and cracked and torn up....and the little rubber tube that goes from the fuel pump to the hard line inside the tank had cracks all through it. anyways i got it replaced and it runs like a beast now..

thanks a lot guys for your help
jeff

 

[4X4HIGH]

Well glad i could help you.