MustangGT-T

I have a 2005 Mustang GT, it has an MMR streetmod 900 shortblock with the original heads and a 76mm turbo. I put stiffer valve springs in it. Lately the car has been running terribly! I will come to a stop or let it idle and it starts knocking terribly until it dies, then I will get a P0345 code... I replaced both cam position sensors and it still does it. I also noticed that as bad as it runs at idle, if i get the car over 3500rpm it will smooth out but if I let it get back to idle it starts all over. The weird thing is, is that it only starts after the car has warmed up and gotten to operating temperature. I don't know where to go from here, I don't know if it is the VCT solenoid or if it is the phaser sprocket... I just want to get the bugs worked out.. It seems to be one thing after the other. If someone can help please please post what you know. I am at a loss as to what to do at this point. Thanks for everything.

socalwrench

It's interesting that you say the problem DOESN'T occur when the engine is cold. The engine is in open loop to improve driveability during warmup. It does this by ignoring the 02 sensors and running a rich fuel mixture.

Most likely your fuel mixture is off. Now what is causing this could be quite a few different things considering you added forced induction to the setup. Regardless, I would bet you're running very lean- enough that the engine begins to misfire and stalls.

MustangGT-T

I thought about that but the problem is, it throws a P0345 code and the car starts to run just fine if you rev it... I t was also intermittent up until just recently. That led me to believe it might be the VCT solenoids or the phaser sprockets. It was also tuned at panhandle performance and I know that Mark is very very careful and conservative with his tunes. He had it running about 11:1 fuel/air ratio. I know that there were some TSB's on the phaser sprockets and VCT solenoids for that car. If there was a misfire I would get a code that let me know that there was a misfire and where the misfire was at. I hope that someone has experienced something similar and can shed some light on the subject so that I don't waste time and money tearing the thing apart and replacing parts that aren't bad. On a sidenote I have a FAST wide band air/fuel meter that reads both sides and it says that everything is great, the problem also only occurs when I allow the engine to idle as I shift or come to a stop. Thanks for the help.

Diabolical!

I'd assume that's at WOT. From the way you describe the problem, it seems the car is leaning out at idle when warm.

MustangGT-T

What is causing the P0345 code then? I am not sure why it would throw a BANK 2 Cam position sensor code if it is leaning out.

MustangGT-T

Anyone got any other ideas? I am all ears!

moosestang

These cars stay in open loop for a few minutes. Mine is usually in closed loop before I finish backing out of my driveway.

Who tuned this car? Has it always run poorly since the motor/turbo? Is it knocking at idle?

You need to be more specific.

moosestang

The code could mean a lot of things. Try doing a google search and see how many people get that code on all sorts of cars.

http://www.fordf150.net/forums/viewtopic.php?t=77858

jcthomas

This sounds like the same problem I'm having. At idle and when hot, it starts running real rough. It feels like it's going to stall. I give it a little throttle to bring the RPMs up, then it starts to idle OK. It's intermittent, but seems to be happening more frequently. Runs fine when cruising at speed, in any gear. It's not throwing any codes. I'm running the FR Whipple with the FR tune. A/F ratio fine; no change.

Any update?

bullitt2086

i would take it back to your tunner and have them put it on the lap top and make sure all your parama are were they should be i would double check airfuel and timing