97 silverado 5.7 fuel sys problem. injectors?

[bradrhale]

why do you think that the injectors are stuck?? especially all 8 of them?? you have several other parts that would prevent the injectors from firing. there is a part in the dizzy that controls fuel. there is the ecm. several other things that it could be besides 8 stuck injectors.

[mudseeker]

best thing to do is put it on a scanner and perform an injector test. the scanner can command the injector to spray while you have a gauge hooked up to the schrader valve. watch the gauge drop and you'll know if it's the injectors.

the poppet valve style spider assembly is known to stick, but are you willing to put $500 of parts and labor in this truck for an MFI upgrade and it not be the problem? who takes the hit on that? you or the customer?


Diagnostic Aids
If no trouble is found in the fuel pump circuit or the ignition system and the cause of an Engine Cranks But Will Not Run has not been found, check for the following conditions:

• Fouled spark plugs.
• An EGR valve stuck open.
• Low fuel pressure. Refer to Fuel System Diagnosis.
• Water or foreign material in the fuel system.
• A grounded Ignition Control (IC) signal circuit may cause a No Start or a Start then Stall condition.
• Basic engine problem.

[rodsterdewd]

Thanks for all the info so far guys. i really do appreciate it. the reason i think the injectors are stuck is because the fuel in the truck is over 2 years old and never had stabil mixed in. 6 months ago the cust tried to start the truck after a year and the fuel pump was stuck. he had it replaced and the truck started and ran ok. as far as i know, the truck ran about 5 minutes then was shut down and left for yet another 6 months. thats when i was called... last week. the fuel pump was again stuck so i pulled the tank and found all rubber parts of the pump that were just replaced to be deformed and melted, and the fuel was rotten not just bad. So, because of this and the fact that i have seen many injectors stick from fuel left in the system for over 3 months i feel the bad fuel has gummed up the injectors. nothing else on the truck was touched, there were no weeds or grass anywhere near it, and no one messed with any wires. i checked all fuses from the start and they all tested good. because the truck runs on fuel into the air intake, i must assume the ignition system is also fine. there is brand new fuel in the truck, new pump, new filter as of yesterday and everything just points to gummed up injectors that just cant open because of the gum and varnish. the problem from my view is simple enough. it is the getting to the injectors to tap them or clean them that is holding me up. now that i know where the little sob's are hiding, i know i can't just take something and tap at them with the motor running to loosen them up. thats why i figured that blasting high pressure into the fuel sys while the injectors are being energized might get them to free up. i forgot about the regulator, so i dont imagine i will get much more pressure then the regulator is set for... sending the excess pressure back to the fuel tank via the return lines. i have no computer to hook up to the truck and nothing to service efi systems, so i really have no way to test anything electronic except for the ol fashioned way with my digital multi meter. So, if any caveman mechanics have any more idea's... ill be standing by. at the time i started this thread i was completely unaware of the "spider" system, so i am already further ahead then when i first got here. finding out how to get to the suckers without breaking anything is my next goal. if this can't be done without opening pandora's box, then the cust will probably just junk the truck. he is NOT going to spend 800 dollars on fuel system to sell the truck for a grand.
I just thought the extra info will help you all know where we are with this.

[mudseeker]

mabye this will help you out.
upper intake removal