MY350Z.COM - Nissan 350Z and 370Z Forum Discussion - No throttle response after clutch install

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No throttle response after clutch install (SOLUTION IN THREAD)

Im at a complete loss as to what is causing this issue, please let me know if anyone of you have had this issue and how you went about fixing it. Before I start, I have searched for HOURS for the past couple weeks trying to find a solution but every thread is the same, person asks similar question to my issue and NO RESPONSE AFTER THEY HAVE FIXED IT.

This started about 3 weeks ago when i installed my new z1 clutch, in my 2004 350z. Everything went completely fine with the install up until the point when i went to start it. It had trouble starting the first few cranks but whatever. After a couple tries it fires up to about 2k rpms but i wasnt giving the car any throttle. I try to rev the car but it is idling at around 1k (when warm) and wont rev past 1.5k no matter what. I got codes which are: P02127, P02138, P0222, P0123, P02135. All of which are relatedto the throttle body/ pedal position sensor. Okay no big deal, i swap out the throttle body with a spare i had laying around and ordered a new throttle pedal assembly and installed both with the battery disconnected. Still getting the same codes even after clearing them. The next step would be to do the ecu relearn, however i cant do this because the FSM explicity states that you cannot complete the relearn when your throttle pedal sensor is not reading. Ive tried countless times to “unplug your battery to reset the ecu” and tried doing the pedal dance for an hour straight but it will not work. My next step is getting my car towed to the dealer so they can plug in their computer to force it to do the relearn, but who knows whether that will fix my issue or not.. In the case that that doesnt fix it what would my next step be to find what is causing it? Check continuity on all my wires? Ive tested voltage to the throttle body and it came back reading within spec so ive ruled that out. Could it be a fried ecu? Fried IPDM? Wiring harness short? The part of this that makes my head hurt is when i swapped out the clutch I never even touched the wires that lead to the throttle body. Only the crank sensor, starter and transmission sensors (all of which are in working order). Ive asked a couple facebook groups and searched forums tirelessly to find an answer but i can find no definitive answer. Some reported saying that a new throttle body or pedal sensor worked, a few said their ecus and ipdms were toast but many of those people only had the issue after driving in rain (which my doesnt doesnt get driven when it rains so i can rule out a short via water). If anyone has any help it would be appreciated

You probably didnt index the flywheel correctly. Did you make sure to align the down pin with the hole in the flange on the engine?

Quote:

Originally Posted by guitman32 (Post 10978533)

You probably didnt index the flywheel correctly. Did you make sure to align the down pin with the hole in the flange on the engine?

I am 1000% sure the flywheel was installed with the correct orientation. I had a bad pilot bearing a few months ago and when i swapped that out i installed the flywheel incorrectly and got the crankshaft sensor code. Car ran like crap but i drove it until i pulled the trigger and decided to drop my trans again and install the clutch this time. Before installing the flywheel i checked at least 3 times to make sure it was going in the right way and i am absolutely certain it is. I dont have the crankshaft code anymore (since the flywheel is on properly now). What I am thinking happened is the ecu is used to the flywheel being installed incorrectly and now that it has been corrected the ecu is freaking out thinking i am on the throttle when im actually not, not sure if my logic is 100% there but thats all i can come up with. But as i said, cant do the ecu relearn since my throttle pedal doesnt work

for some reason looks like you need to do a throttle body relearn... did you take of the tb while doing the tranny ?

Quote:

Originally Posted by rustyschopshop (Post 10978539)

for some reason looks like you need to do a throttle body relearn... did you take of the tb while doing the tranny ?

throttle body only came off after the install when I initially pulled the codes. I didnt take it off during the install

one of the codes identifies tb relearn needed.

Okay guys, the problem has been resolved although it left my local shop scratching their heads trying to diagnose it. First they thought it was the pedal sensors, didnt work. Then they figured it was a fried ecu, wasnt that either. Here is a quote word for word from the diagnostic sheet they gave to me explaining what went wrong.

"When replacing ecm found 5 volt reference to APP 2 circuit still grounded. Pin 91 at ecm shows not connected to any other wires but tech found pin 91 connected internally through ecm to pin 47. Pin 91 is connected internally through the ecm to pin 47. Pin 47 is another 5 volt reference wire. The 5 volt reference was removed from other components during testing to eliminate shorted components. Pin 47 is shorted to its shield and due to the short so close to the pcm, tech would have needed to cut wire to find short. Had 6 DTC's related to each other. Tech cut the shield from ground at pin 47 to elinimate the short to ground at pcm. Tech programmed electric controlled throttle body and accelerator pedal. Car now drives normally with no DTC"

My best advice to anyone experiencing this issue is to take your car to a REPUTABLE shop that also specializes in electrical/wiring issues. I spoke with the tech and he couldnt give me a definite answers as to why this happened after just replacing my clutch, it could have just been a fluke thing but we dont really know at this point, im just glad to have my car back.