It doesn't look like power LOSS, it looks like the ECM is responding to something and cutting throttle angle, cutting advance or sending wrong fuel pulse width for actual air fuel ratio. Could solve this really easy with a full datastream readout during the condition.

I think you would have mentioned it, but does the exhaust smell rich during the problem?

 

I dug through IATN, a forum for techs with problems and fixes. Three similar vehicles with similar problems, one was MAF, one was clogged Cats, and one had high alternator output causing ECM failsafe.

 

Maf was swapped with a spare, don't have cats. Voltage guage reads around 14 volts when running which seems normal to me.

I'm just going to have to wait till my uprev arrives. Its being shipped from Cali to Florida by usps... I wont be seeing it til the end of next week.

 

So i noticed something today. My car ran great when i went out for lunch today, while driving i happen to notice my volt gauge was reading lower then normal. Right around "13.8" volts which normally it runs a 14 plus volts. Ran a couple errands and car would run great when the voltage was lower.

Is there a safe mode if the alternator is overcharging?

 

I've never check mine with a meter, but the volt gauge reads high for a while then dips after that. I would rule that out.

 

You're right car ran good with high voltage reading the next day.. also the guy who has my uprev had told me it shipped over a week ago, but then text me back yesterday saying "sorry I haven't shipped it yet".

 

The voltmeter isn't highly accurate, the uprev should show you the voltage the ecm is receiving. There is a safe mode for high output.

 

Finally got my uprev back in.. Logged the car, only thing is i cant make any sense of the log cause im not sure what to look for.

Would anyone be willing to suggest to me things i should be looking for, or maybe even take a look at it its self.

Much appreciated,
Clayton

 

I am having the same exact issue. I have a thread created for it. I cleaned the TB but it was only a brief fix. Do your car run better the more you run it. Like if you're running errands all day towards the 2nd and 3rd start and go it's as if the problem is fixed?

 

After market wheels.....what size tires?

 

I was testing the car last night and noticed that the throttle position sensor and pedal position sensor are reading at the incorrect voltages. When the car would run bad the PEDAL would read 4.80 volts (full throttle) while the TPS would read 1.35 to 2.53(quarter to half throttle). I dont think its a sync issue cause sometimes when i floor it would read full throttle voltage on the pedal and the TPS would read full throttle voltage then drop off to around 1.30 volts which is when the car would lose power.

I've done the throttle relearn and I've also swapped throttle bodies from one of my spare motors to test.
Im out of ideas..

My next plan of action is to update my engine harness and ecu from the 2003 and install a 2005 harness and ecu which has wideband O2 sensors.

 

That shouldn't be and issue with TC/VDC off.
It runs the same no matter what i do.

 

Engine harness is my bet. Sounds like you have a bad connection or ground somewhere.

 

Backprobe the TPS signals at the throttle body itself and do a voltage drop from there to the ECM.

 

I would start looking closely at the wiring before swapping it out. Usually when there's a wiring problem it's because a wire has been smashed or worn through. Are the 2005 ecu and harness from a non-rev-up?

 

The harness and ecu is non rev-up. Also now that you mention it, I remember there being some damaged wires in the body harness. The kid i bought the car from said the washer tank wires were ripped out from the car being so low. Ill have to look into that a little further.

 

Do you have a DVOM? Watch the TPS voltage while parked and hold the throttle at a steady spot, then go wiggle the **** out of the harness starting from the throttle body connector all the way to the IPDM at the battery and see if you can make it glitch.

 

There's a place to start. I would be looking at all the wiring there, and anywhere else that could've been damaged along the way.

 

GREAT NEWS! I finally figured out the issue to my problem, turns out my ECU was on the frits. I ordered an 05 harness and and 05 ECU cause i wanted to update to the wide band 02 sensors anyways took it to the dealer had the keys programmed and its been great since then.

I appreciate anyone and everyone that was offering suggestions on fixing this thing. Thanks for all the help.

Clayton

 

Congrats!