RB30ET missfire/ignition problems.

Nistune topics specific to the 6802 cpu

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87calais
 

Posts: 25
Joined: Tue Mar 18, 2008 4:58 pm
Location: Cessnock, NSW

Re: RB30ET missfire/ignition problems.

Post by 87calais »

So, went out to start working on it today, fired it up , no miss or anything, took it for a drive, fine. gave the harness a good workout, no problem...
It was playing up when i put it in the shed on Tuesday, fine now. Yanked the harness anyway, I'll cut it open and have a good look over it.

Updated to the latest version of nistune, did some testing on the voltage drop displayed in nistune. With the engine running i have 14.2 volts everywhere, except in nistune? Nistune displays 13.3 volts. It measures 14.2 volts at the wiring harness connector for the ecu. Is there something i can check in the ecu that could be causing it to display low? or is there anything in nistune or the address file that would be causing it?

Also, she needs a bit of work on the cold starts. Now according to the Mapping Guide, the table i should be adjusting is the "coolant temperature enrichment coefficient", however i don't seem to have that table? I have the cold start, warm start, first start & after start, but they don't seem to effect how it runs, and according to the mapping guide they are only accessed while the start switch is engaged. Could someone please correct me if I'm wrong, or point me to which table i should be adjusting?

Thanks guys.
Scott.
Matt
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Re: RB30ET missfire/ignition problems.

Post by Matt »

The voltage of the battery is what is read on the actual line of the A/D converter chip inside the ECU. If you are measuring a different voltage on the input pin of the ECU then not sure why there is a drop but wouldnt be too worried about it

Cold start <= 15 degC
Warm start >= 15 degC

Change these values around the temperature selected whilst warming up and they will have effect until 85 degC. I have been modfiying these tables on my R31 to fix up warm start issues after using the Z32 AFM
87calais
 

Posts: 25
Joined: Tue Mar 18, 2008 4:58 pm
Location: Cessnock, NSW

Re: RB30ET missfire/ignition problems.

Post by 87calais »

Update.
Checked the engine harness with a multimeter, found a bad connection on the negative wire from the noise suppressor (capacitor), and also a broken wire from the coil to the capacitor. Not completely broken, about 2 strands of wire left in tact. Everything else checked out ok. Haven't had the car running yet to see if its fixed it, but fingers crossed. I've undertaken a few other little jobs while its off the road, so will be a week or so before its running.

Scott.
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