Hondata

sleeved JDM gsr 9:1, type r head, pro 2 cams...

Hardly drive car as it's an enjoyment/race car for the wife and I. Well, last week we took it out for a cruise and 1st 15 minutes car ran fine, then started wanting to stall. Had to hold throttle slightly to keep car running. When I got home, I held throttle at 3,000 RPM, slowly lowered it until it wanted to stall. got to around 2,500 and it would drop to about 1,100 and then go back up to what I was holding at... If I let off any more car stalls. Per a recommendation, changed the plugs, and intake air temp sensor. Well, changed those, same problem. Adjusted TPS sensor, per datalog TPS was at 2% when throttle closed, adjusted that to 0% by loosening tps bolts and rotating while watching tps % on datalog. After that, same problem. Car has Mustang TB, no IAC, AEM 5 bar map and wideband. Attached Datalog... Please help.

Thank you

FYI, car originally tuned by Evans, car was running fine and strong for 3 months so I think something went wrong somewhere...

With no IACV and a stalling car I would say it is probably a problem with the throttle body itself. It probably needs to be adjusted to allow it to idle. You could also try using a stock throttle body that can use an IACV.

Thanks for the idea. I'll keep that in mind. Thing is it's not like it was doing this after the TB was put on, setup was built with that TB and car was running perfectly... A mustang TB with no vac assist an IAC shouldn't cause the idle to fluc like that, so I am thinking something electrically isn't right somewhere?

Any one else?

Update...

Changed the TPS sensor, car idled perfectly when cold, as soon as it began to warm up, it stalled. Restarted it, held it at 2,500 again, still surging, but now just noticed when it's warm?

Any one???

:edit: it probably always was doing it warm just thought that may be of importance to someone who can help.

If Your Car Is ODBII, Then Go Into Your Parameters Settings Then Click on The MISC. Tab & Right After All The Disable Check Boxes There should be A check box that say Invert-Purge Valve. Hondata recommends all OBDII cars to check this box or if your car is stalling during warm idle. Or it could be a very Simple problem as really low coolant level which causing idle surge or stalling.