Xintar

I had a new engine put into my 99 z28, and the tech has been banging his head trying to figure out why cylinders 6 and 8 keep flooding. The PCM has been replaced and everything seems to be ok mechanically. Any ideas?

Thanks

conan

iTrader: (5)

Have you tried to switch the injectors and see it the problem moves with the injectors.

YoMommasTA

iTrader: (1)

bad injectors....i hope it hasnt ruined the new engine already.look for rust in the fuel rail,the rust will jam the injectors open.may block others,turns into a huge mess.its more common than most realize.the fuel rails on these gen 3 engines are plain carbon steel.rust very easily.each injector has a small inlet screen to try and catch some debris.what usually happens is some of the smaller rust particles get through the screens jamming some injectors open.sometimes the rust will just block the injector screen completely.there is a service bull from gm on this someplace i seen it.its a big problem in the newer trucks too.i've seen a few engines hydro lock from cylinders filled with fuel from a stuck injector.this can cause extreme damage.what happened to the 1st engine?

Xintar

The injectors looked good on inspection, so I'm really at a loss. I think the motor itself is bad so I'm looking for a new one instead of dealing with a headache of tearing down the right bank again.

The first engine started clicking one afternoon and I found a needle bearing for the lifters in the oil. The lifter was stuck in the cylinder and it would have caused too much damage to pull it out and do a hone so a new motor seemed like the easiest route.

I've spent too much time in a rental car to tear down and see why the cylinders are getting flooded, so its on to motor # 3.

YoMommasTA

iTrader: (1)

looked good? please explain that term,i meant to do a complete test on them.there is only a couple things that could flood a cylinder.it should be very easy to eliminate all of them with a few tests.is a dealer working on the car?1 injectors leaking or sticking open from rust-debris. 2 no compression(broken valve springs etc. 3 no spark(bad pcm,coil,plug,ground,etc. 4 blocked exhaust or exhaust valves not opening. 5 electrical problem or short holding injectors on(remember the injectors are powered all the time,the pcm only grounds them to turn them on.


Seriously this should be a reasonably easy thing to diagnose.hell unplug the injectors on those cylinders and see if they still foul!

Xintar

Its not being worked on by a dealer, its at local mechanic right now. They ran tests on the injectors, done compression tests and checked the plugs, but there is still something not right thats causing problems. I've given up on the issue as its too much of a headache to me. The guy I bought the motor from is giving me a full refund, so I'm on to finding another.

I really do appreciate the help and I've learned something for next time when I do the work myself.