Strange fuelling issue with idle

[AJRacing-SA]

Hi

Having serious issues trying to tune a car now thats doing my head in.

Car is EP3 Type R with greddy turbo kit. PRA ECU s/n 52193 KManager v4.4.4

As i've mentioned, on idle, I'll dial the fuel in to within 2% s.trim and everything will be looking good. I'll then turn the car off, upload the map, start straight up again, and fuelling will go to -27% and still not reach stoich. Then in live mode, I'll pull 1% fuel, and the car will almost cut off from going so lean, it then starts adding 10% to reach stoich. Part throttle isn't as bad, but still drifts quite a lot. Just can never seem to dial it in.

Changed multiple fuel pumps, done a return fuel system, fitted RDX injectors, stock injectors, ID1000cc's, returned fuel system back to stock with no return and I'm still having the issue.

Attached is the calibration with two datalogs.

At times it seems like 1% fuel change is the equivalent to 20% and other times like 20% is the equivalent of 5%.

Can't understand what is going on here.

Thanks

[Hondata]

A 2ms injector duration at idle for 1000cc injectors is fairly high. Stock injectors usually are around that duration.

It could be the injector drivers in the ECU - they can get damaged and then not provide enough current to drive the injectors very well.

Of course, you have checked the fuel pressure on the rail?

[AJRacing-SA]

Hi, thanks for the prompt reply.

Can't see it now with the stock fuel system back on, but it held rocksolid on idle when the return system was connected with the adj. fpr. so don't think that is an issue.

Just read another thread now about a guy complaining about funky fuelling issues happening to him on the 0 degree cam angle, so changed all the n/a low cam angles to 10 degrees including on idle.

It doesn't want to idle on 10 degree once its commands it after about 25 seconds of idling, but the S.trim's seem to be consistant now after uploading and restarting. Tested it about 5 times now, and was pretty close on every startup. VTC does increase if I give it a rev though. Injector ms is down to about 1.7ms now and it almost seems like its fixed. Will have to go back to tuning the car tomorrow and see if it is going to stay consistent.

Looks like there is something odd going on with the 0 degree fuel table.

[AJRacing-SA]

Ok, so off going off this thread here... viewtopic.php?f=12&t=23568 I've removed 0 degrees completely from my cam angle maps and everything seems to be working 100%.

Can't believe I've been struggling for 2 weeks now replacing every conceivable part of the fuel system trying to hunt down this issue:(