Car runs and idles i replaced the ECM and it actually showed what is wrong. IAC was stuck i cleaned it out and cleaned the throttle body. Fuel trims are still pretty rich but not as bad as they were. Its running between -40 and -20 depending on pressure outside. Has a misfire at idle i think its the actual coil pack itself or the motor is still not getting enough air at idle. Regardless at this point its fine tuning i will go get a pressure test later on down the road but for right now it runs and drives which is all i needed thanks to everyone that helped!

 

So got the fuel pressure tested and its sitting at 57 psi roughly at idle. Got a code its P0172 bank 1 too rich. ECM has been replaced car does run. Im puzzled as to what it could be now. Any ideas would help!

 

Are you getting any other Pxxxx codes? Even apparently unrelated codes? The engine is still running too rich, and the PCM recognizes that. Too rich means more fuel is being introduced into the engine than the engine needs to function properly/efficiently. Fuel is primarily introduced to the engine via the fuel injectors -- and those have been replaced with correct new ones. The PCM controls how much fuel the injectors are introducing, and the PCM has been replaced. The PCM sees the rich condition (based on the upstream O2 sensor) and is trying to reduce the condition by reducing fuel and setting the P0172 code. Correct so far? And your current question is why is the engine running so rich that the PCM has to make such a big correction?

Reading through a couple of sources, at least two other possibilities can contribute to rich running. One is a saturated charcoal canister (overfilling the gas tank?). But this would not be continuous, as the canister is only vented/opened to the engine during the scheduled emission control checks, which don't necessarily happen on every engine run cycle, and only for a few minutes when they do. Additionally, in this situation, you would also probably get a P044x or P045x code.

Another possibility is excess fuel in the crankcase. The PCV system pulls fumes from the crankcase directly into the intake manifold. Before you got the PCM replaced, the injectors were obviously throwing a lot of extra fuel into the engine (fuel trim -50 all the time), and very probably washing down the cylinder walls into the crankcase. Pull the dipstick and see if the oil smells like fuel. A quick oil change if there's any doubt, and then recheck your numbers.

 

Was the PCM recalibrated or reflashed to match your VIN? Was it grabbed out of the same model in a junkyard?

I don't know what the fuel spec is for an ion, but that sounds high

 

everything you say is correct but i have noticed a lot of blow by from the PCV system even at the oil cap there is a lot of pressure. I changed oil after the head gasket repair so its fairly fresh. I have an idea maybe of pulling the evap line this would of course start a vaccum leak but if the numbers go lean then that may be my issue. I have no other codes just the rich running code. The fuel trims are different than they used to be since the PCM replacement. Short term is now -40 when it was -50 and long term is -30 when it was -0.8. The car now instead of straightening out at WOT now almost stalls under WOT. The VIN has been programmed to the new ECM. Another thing ive noticed is the IAC will close sometimes and when it does the car will not start and idle on its own after that. Not sure if that info helps but it gives some more insight to possibly help.

 

Somebody correct me if I'm wrong but it's the long-term trim that you should be worried about in a situation like this. -0.8 not optimal but not too bad.
-30 long-term? That's richer than it was before you changed anything. I'm surprised it runs at all.

Creating a vacuum link will add air to the mix but the ECM won't know about it because it will be unmetered or shall we say not measured so the ECM can't include it in any calculations because it doesn't know how much it is. I would not go that route.

Now we know why you have a p0172. Long-term trim is outrageously rich and the ECM has run out of adjustment space to address it.

I found this in a post on Saturnfans

That is a combination filter-regulator unit. It reduces the pressure from the pump down to the 40-50 lb range. Is the return line pinched? there are 2 lines to the rear and 1 to the front from the filter. The small one of the 2 is the return line. It sounds like you got a bad filter

The only way you have fuel pressure that high is if the regulator is not properly regulating or the fuel cannot freely flow back through the return line to the tank. Check to see if the return line to the tank is pinched or plugged. Have something around to catch the fuel and wear I protection because if it's not clogged, you'll have fuel blasting out of that return line . Should be about 40 psi, but if it's not flowing freely it will be lower. The only other place for fuel to go is up to the fuel rail and it will do so at whatever pressure it is after it leaves the regulator in the back.

 

Have you actually changed the PCV and checked the hose for blockage? That might be the issue with the crankcase pressure. Get a GM PCV, not some cheap piece of junk from adoreilzone.

 

i dont think this is a PCV valve issue i think this is the motor having a lot of blow by regardless i still dont think this is enough to cause the car to run like this

 

Why do you insist on ignoring 80% of the advice people try to give you on this?

If you were correct all the time, your car wouldn't run like this.

Are we correct all the time? Hell no.

People explain to you how the PCV can be an issue. You explain it away. And do nothing.

People explain why your fuel pressure is so high, how it can be that way, and you ignore the suggestions on how to find out if that is the cause.

If you're going to keep ignoring suggestions, what you'll find is the number of people responding to your posts will equal zero.

So follow the advice we are giving or just shut up and go somewhere else.

 

a simple cylinder leak down test from a co-worker says cylinder 2 and 3 have bad piston rings we assume which would lead to the high crank case pressure the PCV system seems to be in the valve cover replacing that would almost be a waste of time and will likely not get me anywhere closer to fixing the actual issue. Now answer me this how significantly can this effect the running condition of the car? Will it make it not idle at all? Will it cause the car to violently backfire when lifting the throttle? Will it cause a misfire so bad the car borderline shuts off? Ive had bad pcv systems and nothing that bad will cause this i can assure you. Im not denying suggestions im confirming and giving my ideas. Call it comparing thoughts its a common practice.