so I got this great idea to put some serious money into my 05 gt on some relatively straight forward modifications only to be met with a lot of frustration. I bought a pair of comp cams ***** thumpa bumpsticks along with the phaser limiters, underdrive pulleys, msd coils, charge motion delete platesr, stainless bbk long tubes, and some other mods to chasis and suspension. I went through bama tunes for the sct tuner and custom tunes for the cams on 93 octane pump gas. heres the problem, the car wouldn't start right after we were done putting it all together. the only way to get it to start was to play with the accelerator pedal when cranking, then it would start, but would die as soon as you let off the pedal, no idle. called up bama and they reviewed the tunes and said there were no problems in the programing, they claimed in a nutshell that we didn't know what we were doing.
miraculously over night the car must have gotten its head straight, cause it would start and kind of idle, but it was running really rich. we took it out for a run and within 10-15 minutes through a check engine light. we took it back and it came up with two codes P0345 and P0349. cam sensor codes. I read online through forums on how finicky the charging system is on these cars and all fingers pointed to a bad diode in the voltage regulator in the alternator. so we replaced the alternator with a new one. ran unbelievably well for about 10 minutes and then went back to throwing the same two codes, P0345 and P0349. since then we have replaced both cam sensors and the crank sensor with no luck. we have another alternator but we haven't put it in yet.
I need help. this car has been sitting at his garage for over a month and were just standing around scratching our heads and running out of possible ways to remedy the situation. I was hoping to be able to drive it before the snow hit, now I just want to get it back in my garage and covered up before its covered in snow.

hopefully theres someone out there who has dealt with this or can help.
thanks,
ryan

 

Does your Bama tune account for the phaser limiters?

 

yes, the tune takes both the cam phaser limiters and the cmdp's into account. it will run and drive, but if you take it out of gear(like when coasting to a stop) the rpm will surge badly from 200-300 up to 1000-1200. sometimes it will surge hard enough to die, other times it will surge 2-3 times and go back to idle, which is set at 890rpm. runs rich all the time. we've torn the top half of the engine apart 3 times now and chain timing is dead on. we have also turned the engine over by hand with a 1/2 ratchet 3-4 times every time it was apart to make sure there was no mechanical interference with valves/pistons.

the only time it ran the way it should was after we replaced the alternator, but that only lasted for about 10-15 minutes.

 

I consulted American muscle on wheter or not I would need a bigger alternator because of the cams/underdrive pulleys, but im not running any subs or amps so they said it wouldn't be necessary. the car has a manual transmission, whether or not that helps.

 

Are you sure that the MAF, throttle body, and fuel rail connectors are plugged in securely? Also, do you hear any hissing/vacuum leaks under the hood?

 

Sorry to hear about your troubles trying to get this project started aspblackstang05!

I'm trying to think of what could be causing these codes, and it seems most cases it points back to a faulty alternator. It's possible your old alternator was on its way out and not charging the system to specs. Thus, when paired with the underdrive pullies, it's not enough charge to keep the system running properly. Your coils need enough voltage to send a proper spark to the plugs. If a weak spark is occurring, the engine will run significantly rich with lots of hesitation or even stall. It's running rich because the spark is not strong enough to ignite the entire combustion chamber air/fuel mixture before the exhaust cycle starts.

Basically, even though you may not need a more powerful alternator, the engine could be struggling from a weak alternator that's also being under spun with underdrive pullies. However, I just saw that you replaced the alternator with new. The fact that the car ran strong after a cold start for 10-15minutes is interesting too.

My next thought is your battery. Do you know how old it is? I wonder if it's not holding enough charger and causing this issue, the same way an weak alternator would. My reasoning for this is- an alternator has the ability to make max voltage when it's cold. If the car ran okay for 10-15 minutes, it's possible the new COLD alternator was producing just enough voltage. Once the engine bay started heating up significantly, the alternator's output voltage will lower. Which, could be just enough to cause your problem.

At the least, I would remove the battery and having it tested at a local Auto Service station. They'll be able to tell you how much life it has left. Then post back with any update you found. We'll keep trouble shooting if necessary!

Hope this helps!

Shane

 

everything is plugged in/commected, except for the motor that would have controlled the charge motion plates. the tunes are written with that motor deleted, there fore it isn't even on the engine or plugged in. cant say that ive heard any hissing sounds or anything like a vacuum leak.
everything keeps pointing back at the cam sensors. p0345 and p0349 are the only two codes that the computer is throwing.
the throttle body is aftermarket. it is the bbk twin 62mm I believe. as for the battery, it is a optima red top, and its been on the car since ive owned it (going on 2 years) and have never had a problem with it. im also the 3rd owner of the vehicle and i never had any problems with it until I did all this work to it. guess I should have left it alone.

 

as I mentioned earlier, the only time it ran like it was supposed to was after we replaced the alternator. I took it out for a spin to the gas station to put gas in it, which was about a 10-15 minute drive. it went back to running like crap when I started it back up after filling it, and hasn't run the same since. that one time it ran good was a one time occurrence and hasn't run that good since. its making me think that maybe I just got a dud alternator.

 

By the sounds of it, you've let the car completely cool down for multiple hours and then started it back up with the issues still there- correct?

It's not impossible that you've received a faulty alternator. I've seen this happen maybe 3 total times in my life time, so I wouldn't call it common. Never-the-less it's not impossible. The fact that it ran perfect for 10-12 minutes is what's most confusing. Something is missing here!

Where did you purchase the alternator? Do you still have the receipt? If it's a local shop/store, they can most likely test it for you.

Shane

 

The owner of the garage that is doing the work on the car ordered it from one of his suppliers. They have honored it as a replacement and sent him a new one free of charge.