First off I must apologize as I put this post in the wrong forum. So here goes...96 ext cab 2wd,at. 256k . This truck runs strong except it drops #7 for no reason(none that I can find) complete fresh tune up. compression good all cyls. Sometimes it runs for weeks and no problem and then it will occure days at a time. self fixes and the ses lite goes out with no reset! Fuel pump is new. Any help will be appreciated as I have little hair left to tear out at this point.

 

I guess you happen to catch a code at times since you say #7. This is a misfire?

 

Yes all the code says is misfire #7 . No other info

 

With 256k on the clock could it be a timing chain issue? Dist shaft is within tolerance and not the least bit loose. I assume this is a mechanical problem and not related to anything vaccum or electrical.

 

I'd say not a timming chain, reason being (I assume it is just the one cylinder misfire?) it is just one, and the same cylinder? If it were a timming chain, I'd think it would be an over all problem with all 8.

 

wait till dark and spray soapy water all over wires and distributor. report back.

2nd guess is - crack in the engine head or head gasket at #7.

 

already did the water trick and anyway wires and cap are new so no cross fire or leakage. Don't believe it's a cracked head or gasket cause compression is good and it does'nt occure on a regulr basis. as I said it may go for weeks and not screw up.also the plug looks good ,nice lite tan color ,no water or oil fouling.

 

poppet injector sticking? thats about the milage mine had on it when #5 poppet stuck closed


Sean

97 4x4 burb

 

I hate to say it but thats all I have left and taking that spyder apart is a pain. I might try some "Sea Foam" gas additive first.

Thanks

 

try the Sea Foam first you can get that upgraded spider assy on amazon for about $215 i wouldn't mess with the old one


Sean

97 4x4 burb