Strange Problem w/ APS TT
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Strange Problem w/ APS TT
To all you gurus... Your help would be HIGHLY appreciated.
I just had an APS TT installed by a local authorized APS dealer. I thought I was going to be back in my car by now, but it would seem that the FI gods are not smiling on me. Simply put, my car is F***ed up. Here are the symptoms:
The car starts perfectly and runs under partial throtle very well; however, at WOT, boost will build to between 4-6 psi and then the motor dies... I have not personally seen it, but it sounds like when the stock ECU cuts fuel. The ecu is occasionally throwing a CAS code.
The unichip has a 93 octane base map from GRD on it; the unichip was sent back to them and they retested it and confirmed the map was properly loaded. I believe the unichip was also run in another car and it worked fine. The a/f numbers are within a safe range. The crank angle sensor and the MAF sensor have both been swapped out and the problem remains. I have no ECU reflash.
So the million dollar question: WTF is wrong with my car?
I just had an APS TT installed by a local authorized APS dealer. I thought I was going to be back in my car by now, but it would seem that the FI gods are not smiling on me. Simply put, my car is F***ed up. Here are the symptoms:
The car starts perfectly and runs under partial throtle very well; however, at WOT, boost will build to between 4-6 psi and then the motor dies... I have not personally seen it, but it sounds like when the stock ECU cuts fuel. The ecu is occasionally throwing a CAS code.
The unichip has a 93 octane base map from GRD on it; the unichip was sent back to them and they retested it and confirmed the map was properly loaded. I believe the unichip was also run in another car and it worked fine. The a/f numbers are within a safe range. The crank angle sensor and the MAF sensor have both been swapped out and the problem remains. I have no ECU reflash.
So the million dollar question: WTF is wrong with my car?
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Originally Posted by ZON
Yeah, it's an install problem. They fuked it, they fix it.
My point in posting was not to ascribe fault, it was to get some fresh opinions on the problem to speed up the process.
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Originally Posted by 350Zteve
Sounds like the CAS wire was done wrong
And if the CAS wire was not done right the car would have a hard time starting.
Did you change the clutch or flywheel?
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Originally Posted by westpak
It can't be done wrong by the installer as it is wired in to the harness from APS.
And if the CAS wire was not done right the car would have a hard time starting.
Did you change the clutch or flywheel?
And if the CAS wire was not done right the car would have a hard time starting.
Did you change the clutch or flywheel?
Yes, I had an RPS flywheel and max street clutch installed at the same time. Could this be causing issues? It seems so disconnected.
My current "best bets" are MAF or TPS issues... thoughts?
Last edited by ht4; 02-14-2006 at 07:04 AM.
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I know that my APS dealer that installed mine had a problem with a APS TT install on one car. They used mine to look at the CAS wire connection that APS wired, and found the one on the other car wired incorrectly from APS. Since APS will not send a wiring diagram (so you can't copy their system), troubleshooting the system is a nightmare. If you want to talk to the shop I use, PM me and I will send you their name.
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Originally Posted by MoodDude
I know that my APS dealer that installed mine had a problem with a APS TT install on one car. They used mine to look at the CAS wire connection that APS wired, and found the one on the other car wired incorrectly from APS. Since APS will not send a wiring diagram (so you can't copy their system), troubleshooting the system is a nightmare. If you want to talk to the shop I use, PM me and I will send you their name.
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The car is also showing the slip/vdc light... The installer is sure it was installed at the same angle, but is going to check this anyway. We are going to disable the VDC to see if the problem persists. Anyone know how to reset the VDC?
Any other thoughts?
Thanks!
Any other thoughts?
Thanks!
Last edited by ht4; 02-14-2006 at 03:11 PM.
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Originally Posted by Sharif@Forged
It could be a defective or shorted UNICHIP PnP harness. After scanning those codes, I would swap it for another UNICHIP and harness and see if the problem remains.
You hit on another strange part of this problem. Before my unichip was sent back to GRD to be reflashed, another unichip was put in my car and it worked fine. However, after reflashing the unichip and trying it (with no success), even the other unichip doesn't work... thus adding to my problems.
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Just a guess though it sounds like the clamp on the mass air flow sensor is not correctly set, if the voltage goes above 4.9 volts the engine will fuel cut for sure. It would also pay to check the crank angle sensor and if you have fitted an aftermarket flywheel this could also upset the CAS signal, a few possibilities for you to check out.
Goerge
Goerge
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Originally Posted by georgec
Just a guess though it sounds like the clamp on the mass air flow sensor is not correctly set, if the voltage goes above 4.9 volts the engine will fuel cut for sure. It would also pay to check the crank angle sensor and if you have fitted an aftermarket flywheel this could also upset the CAS signal, a few possibilities for you to check out.
Goerge
Goerge
Peter mentioned the voltage clamp issue on the other forum. Can you explain how this can be fixed if it is the problem. Can this be easily fixed by any unichip tuner? which, as you know, my shop is...
Thank you very much for your help!
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Originally Posted by failsafe306
Could the steering wheel not be correctly aligned? Since he's getting the VDC/SLIP light...just a thought.
The guys who did my install tell me that because of the splines in the steering shaft hook-up, it is pretty hard to mess up so that also tells me that is likely not the problem... In any case, assuming it is the issue, do you know how to reset the VDC system?