jdm95

Okay to start out ive got a turbo DC2 GSR. Im running a Neptune RTP and a omni 2.5 MAP sensor. The problem im running into is im driving either beating on it or normal driving and the car goes completely lean on the wideband and i press the gas and nothing happens, by nothing i mean the engine doesnt even rev at all just nothing, after a couple of seconds it goes back to normal and it wont happen again for a while. Ive tried to recreate it and i cant its just random. Also on top of this my car at idle the air/fuel will go rich to 10.0+ rich and will rev from 300-1000 rpms. This is also random. Ive taken it back to the tuner but whenever i take it its fine no problems.
So im confused whether it would be the Neptune program or my map sensor going bad which i just put in less than 2 months ago. I know mechanically everything is sound and 95% of the time the car runs perfect its just this happening thats confusing the hell out of me. Any help on this would be great i would love it if it was just a MAP sensor.

0mtber

iTrader: (2)

It is doubtful neptune is the issue.

When this occurs, you need to compare your map sensor readings in neptune to your actual manifold pressure to determine if the map sensor or map sensor signal is the issue.

TurboLSVtecTeg

Does the car drop below a certain rpm and then everything goes back to normal?
Can you post up the ncl file? Im guessing you dont have a datalog of the problem?
Also what is your ignition setup?

HRTuning

Sounds like a fuel cut, which could be caused by the map sensor, it's hard to say without a datalog.

Your idle, if normally fine, could also be swinging because of a false map sensor reading, but again, you'll want to get a datalog of the situation before you can fully assess if that's the problem.

jdm95

thanks for all the advice. Its curently my daily driver and it happens so radomly i dont keep a laptop plugged in to it so i cant compare the manifold readings. I just think it strange that its completely random and i cant duplicate it what so ever because ive tried alot. And it with the leaning out and no engine reving problem it does seem alot like fuel cut, mainly because when throttle is applied the vaccum pressure goes from -20 to 0 and thats it nothing else. The reving up and down its also random and starts happening out of now where it goes completly rich and revs like the computer is trying to compensate for the richness reving up and down, correct me if im wrong on this usumption im new at tuning systems. Are there any tell tale signs i can look for that would point whether or not its for sure a map sensor ?.

If i straight replace the map sensor with a new one from the same company/model should i have to have it retuned or will it be fine?? Also until i figure it out is there any damage that can occur due to this?? Its happened quite a few times already over the last month or 2 and everything is fine but i just want to be sure im not driving a time bomb with this happening. Im a little irritated that i payed for a brand new omni and it might be bad, anyone else had omnis that were bad right out of the box?? Thanks again for all the imput and help its much appreciated.

jdm95

To answer your question no it doesnt do it once or twice and go back to normal it starts happening sometimes when i clutch and its at idle or just running at idle and it will keep going until i get back on the throttle( driving) and then next time im at idle ususally its back to normal. Also in my other reply no i dont run a laptop since its my daily. so unfortunately i dont have a datalog file i can put up. Not completely sure of ignition setup since i had a tuner do all that since im really new at it and dont know enough of what im doing to tune myself. I do know that my tuner let me know that he retarded it quite a bit for safety since its my daily. Thanks for the help and i hope i was able to give enough info to fully descibe the issue.

HRTuning

Tough to say... If the map sensor was off to begin with simply replacing it with another of the same model may require some changes. If it was indeed operating normally SOMETIMES it's possible your tune won't need any changes. Logs would honestly be the best way to clear it up, as you can see what the map sensor is doing and how the voltage is changing, etc, as well as the other sensors.