BillS

iTrader: (13)

I pulled apart my engine to try to find the cause of a idle that would climb to 1800 when hi-way driving and also to find out where I was getting smoke out the tailpipes on a warm restart. and recent increase in oil consumption.
I pulled the intake and found that the 2nd from the rear Dr side intake runner is spotlessly clean and the other 7 have a oily-sooty coating. I sent the injectors out to be serviced and that inj was physically broken so no fuel was flowing.
I am about to pull the heads off shortly, but my question is, What dammage could possibly have been done , and what should I be looking for after the heads are off. I have a set of CNC'ed LS6 heads on the way
thanks

Randy WS6

iTrader: (69)

Run a compression test to see if you have any bad rings or a leak down test. You may only need valve steam seals.

BillS

iTrader: (13)

I would, but the engine is in peices, I just hope the shortblock is not hurt.

miller456

iTrader: (36)

your asking a pretty broad question with not a lot of info. Also to pull apart a motor for and idle at 1800 is a lot of work for nothing it sounds like to me. Is your car an m6 or a4? if its an m6 an idle at 1800 until you come to a complete stop isnt that bad. Does the idle stick all the time or does it go away when you come to a stop? You could have a vacuum leak, the car isnt throwing any codes im assuming? You need to give a lot more info if you want better responses.

BillS

iTrader: (13)

I pulled it apart because I knew the heads needed work. Thats when I found the intake port that was spotlessly clean. The car is a M6 car, and I have lived with the high idle, but wanted to fix it while the engine is apart. It will go 70 mph in 6th gear without me touching the gas. When I do come to a complete stop it take 5 sec or so then the idle will drop back down to 8-900rpm.
I really dont know how long the injector has been dead. I just hope that running that cyl with no fuel has not runined the rings/ piston/cyl wall. I would like to avoid pulling the entire motor and rebuilding.

The injector guy just called and said that the inj was broken internally. The stem that the coil pulls on was broken away from the valve seat so no gas was getting thru, but the coil was working and moving the stem. He has never seen that before. The inj's were SVO 30lb units and were flow tested by RC injectors before installation , and they have about 7k on them max after the flowtesting

TooLateVTEC

iTrader: (2)

If it was me, I would get an injector or even a new set to make sure that doesnt happen again and put your new heads on it and reassmble the motor. Do a compression test and see what it reads.

It will be very good or very bad from that point on no matter what.

You could pull the motor now, tear it down and find nothing wrong and wasted all that time for nothing or you could put the motor together and find that it needs to come out and be rebuilt. Either way theres a shitty side.

Good luck.

Ramairbird

iTrader: (17)

If the injector was not opening at all and no fuel was flowing you probobly did no damage to the engine. All that would happen is the piston in that cylinder is along for the ride and the car would have a distinct miss especially at idle and when accelerating. if the injector was spraying some fuel but not enough for all conditions then it could have gone lean in that hole and that could do damage. An injector that was stuck wide open can wash out the rings. Put it together and do a compression test. A bad injector will not cause an idle that hangs. If anything the dead cylinder will tend to pull the idle lower since it is not contributing to making power.

BillS

iTrader: (13)

I am replacing the bad injector and having all 8 gone over to make sure they are flowmatched. I guess I will see what I find when the heads come off. I am almost at that point, just need to pull the PS pump, (and thats a bitch) and headers and then the heads can come off.
I would love to drop a LSX 427 in there , but the moneytree is bare right now.

miller456

iTrader: (36)

You do know that you cant just take 8 injectors and flow match them right? You have to have a bunch of the same injectors, test each one, then use the ones that closest match one another. I assume you mean that you just had those re tested to make sure they were close to one another since you said they were flow matched before.

macool68

Start with the easiest route and go from there. Sounds like you had a bad misfire from the injector not activating. Replace the injector(s), seafoam, and sparkplug change.