Hi all,

I'll keep this as simple as possible - so today I changed the brakes on my 2003 350GT (VQ35DE, automatic transmission) from the peasant-spec single pot calipers to the standard Brembo 350z calipers.

I disconnected the battery at the negative terminal about halfway through the caliper swap (remembered the manual said to do this, too late maybe), and the key was in the ignition (I couldn't remove it with the drive in neutral),

Swapped the calipers, disks and brake lines over, bled them off, refilled the fluid reservoir, wheels on, lowered off the ramp.

When I start it, the revs are jumping between around 1500-2000 constantly. Slip, VDC and ABS lights are on. SES / Engine management light is NOT on.

Nothing in the engine bay has been touched or disconnected at all except the brake fluid reservoir and battery.

I did a quick google while I had signal for all of 30 seconds and found ECU and throttle position reset procedures, tried them (counting seconds in my head, no stopwatch available at the time) and the ecu reset seemed to have it settled for around a minute, but as soon as I touch the accelerator it starts hunting again.

It hasn't moved off the ramp space, I didn't dare try to drive it out in case it started doing it again.

Anyone have a solution?

Thanks in advance

Andrew

 

I tried the reset procedures numerous times today, cleaned the MAF sensor, had a look at PCV, throttle body looked clean. All vac hoses seem to be ok, plugs and wires seem ok.

I took a video before, you can see in this that it idles ok and then decides to have a fit again. I've had it idling normally but every time I did something that puts load on the engine, a small rev, turning on heaters, even windows up and down it goes into spazz mode again. I'm thinking the ECU might be shot if that controls the idle..?

Excuse the boring bit in the middle, I wasn't expecting it to idle properly, usually each time I start it, it goes straight to erratic idle. Skip to 1:07 for that.

 

Tried all the learn procedures again today, no luck. It did the same as in the video.

Any help please guys?

 

Here's a rundown of what's happened and the resolution, may help others in the future.

Basics:

Vac leaks checked out, problem remained.

All earths cleaned up, problem remained.

Looms and plugs checked and cleaned, problem remained.


Components:

Tried 3 different throttle bodies, problem remained so not throttle body.

resistance test on cam position sensors - No resistance across right bank sensor pins, replaced. Issue not resolved.

AFM replaced, problem remained.

VCT solenoids and oilways checked out and cleaned up, no gunk in there anyway, issue still there after.

Plugged in to Nissan data Scan ii via laptop, all codes cleared, idle air volume learn carried out, fixed it for a minute or two and then came back again when revs dropped to base idle of 650 rpm.

ECU clearly not remembering idle volume, or storing codes, ECU doesn't diagnose itself so time to try a different ECU.

Replacement ECU sourced, sent off for NATS removal, fitted, problem solved.

 

Did you try a simple Idle Relearn and TB reset?

BTW: where did you buy your paddle shifters? I'm still searching

 

Yeah of course, numerous times manually and probably the same amount of times through the laptop.

The paddles came with the car, can't remember what the company is called that made them but they don't any more, or at least their website is gone.

 

Wow..crazy, but not the first time I've heard an ECU go out. Bet it was a pain to go through all of that.

Thanks for the info. It could have been Works Bell. Some have used the 2nd Gens paddles and got them to work. It's just fitting them nicely onto steering column is the challenge.