This has intemitently happened 3 times now. Acts like an older car with the timing way too far advanced! Have had it a shop twice in the past. Changed plugs, MAS, bought a used ECM & had it reflashed, changed all O2 sensors. Took the last shop 7 hours to get it running. They said spark plugs fouled bad with fuel. Changed O2 sensors again. This happend once two years ago. Once last December. And yesterday it started acting up again! It has been running just fine. I did recently replace the fuel pump and filter. One guy mentioned once there was some type of fuel valve under the intake? When it did get to the point it won't start at all, it was also slightly backfiring thru the throttle body. Yesterday it fought the starter some, but started, also if you jumped on it from an idle it would have a stutter, then it would wind up ok. I'm a old hot rodder. Please dazzle me!
4.3 vortec, right? You've got the notorious spider injection that has funky issues. Leaks from pressure reg and injectors. May have caused hydraulic kick back in cylinders? Does your oil have gas in it?
December, 19, 2011 AT 8:03 PM
Sorry I forgot to mention, it is a 5.7L Vortec. (350)Automatic, K1500, black stepside. I will check today the possible gas in oil. Also, I try to take very good care of it : -)
December, 19, 2011 AT 11:29 PM
Still has the same injection withsame problems. There is an upgrade from gm meant to cure worst issues.
December, 20, 2011 AT 2:27 PM
Thanks much! It started fine yesterday!Oil seems ok. The upgrade is the pressure reg. & Injectors? Just ask a GM parts Man?
December, 20, 2011 AT 4:15 PM
I would assume so. You can check out the new unit on the internet by searching for spider injection replacement. There are after market varieties also. Ebay has all varieties including your old style brand new.