Code p0308

[michael61182]

I have a 96 tahoe 5.7L with this error code p0308 (cylinder 8 misfire). My check engine light is flashing, which i've read means its constantly misfiring, and it does feel like it. I've changed the plugs, wires, cap and rotor. I did a compression test on 8 and got 120 psi at idle and did not increase when reved to 2500 rpm. I checked cylinder 2 as well and got 120 psi at idle and up to 150 psi reved to 2500 rpm. Any suggestions. I've read some other threads similar and a few mentions egr valve. How would I test for that or test the actual egr valve? Should I do a leak down test? I dont have the tester but my brother in law can bring me his.

 

[lesterl]

Put a teaspoon of oil into the cylinder thru plug hole and see if the compression comes up. If compression stays low you may have a burnt valve or possibly have a leaky/ stuck injector poppet......

 

[michael61182]

ok, when I did the compression test the first time, I did while the truck was running. I did it again the right way, i disconnected the distributor and just cranked it. I got 150 and with the throttle open all the way 180. I checked one other cylinder and got the same results. I'm in the middle of removing the injectors. Is there any way to replace just one injector? I found online where they sold them singles but no one I've talked to know how to take them off separately. I am told you have to replace the whole spider assembly, about $250. But I saw them separately for like $50.

 

[lesterl]

Injectors are individually replaceable, most people AFAIK opt to upgrade to a MPFI kit with an injector at the end instead of poppets.......