Mines Ecu Not Working As It Should After Testing A Stock Ecu In R32 Gtst

[GTR-Night Rider]

Hi I need some help I Have a r32 GTST with a Mines Ecu in it and I was finding it hard to start When cold I would have to pump the Peddle. Once Started the car Ran fine and felt good to drive with out the Rev limit etc and I have a Air/Fuel meter which read Rich on boost. I then got a Stock Ecu and just swapped them around to See if the car would Start with a Stock one and it did but still ruff. and the car was running on Stoich and lost the rev limiter etc. So then I put the Mines Ecu back in and it still runs but i have Lost the Rev limit and it doesn't run on Rich on boost (14psi ) is still on Stoich so now its like it De tuned ?? Is there anything i can do to get it back to Normal back to the Rich and Rev limiter on? I have tried Disconnecting the battery and removed it again and installed it but still the same .... any help would be great Cheers Claude

[StevenCJR31]

suggest you bin the mines ecu and nistune the stock ecu to match your engines mods

[mad082]

it's more likely that the o2 sensor wire was bumped when you changed the ecu and that's causing the different reading from the air fuel gauge (given that the stock ecu should read richer than a tuned ecu). those things are useless anyway. they read off the stock o2 sensor which is a narrow band. your car can actually be leaning out and they can still read rich, because they are designed to work between 14:1 and 15:1 air/fuel ratio, which is lean (it's fine for cruising along, but very lean for hard acceleration). 12:1 is the ideal AFR for full throttle, and up will into the 13's is lean, but will still read as rich on the air fuel gauge.

also, an ecu shouldn't lose it's settings just from unplugging it.

there is also the possibility that the o2 sensor is simply dead. with the stock ecu in, and most likely with the mines as well, the afr should fluctuate between rich and lean at idle and when cruising along with light throttle.

as for the running rough, try letting the fuel pump prime before starting the car (turn the ignition to "on" for a few seconds before turning it all the way to "start"). if the fuel pump is aftermarket then it may need to prime before it will have enough fuel in the system to run properly. but then that will only affect it for a few seconds after starting. if it is rough all the time, then it could be coil packs, spark plugs, ignitor module, afm, or one of many other things causing the issue.

and if the car still had no rev limit on the stock ecu then there is something else going on. the stock limit should be about 7500 to 8500 rpm (depending on the accuracy of the tacho, i've seen them be over 500rpm out at redline compared to a pfc handset reading).

[GTR-Night Rider]

Thanks for this info ill look in to it..

Cheers Claude