ATTN: Turbo V6's

Hey guys back once more with a question. Ok so my boosted baby has been running great now for about 6 weeks just eating up the boost and loving it. About 3 days ago I dropped in a new energizer battery since my last one was crap. However after replacing the battery I didn't even think how that would affect my tuning and ECU, well sure enough all my long hours of tuning were lost when I disconnected the battery cable. So here is the problem:

I restored idle back to normal and the car runs great up until 3000 rpm's. Once I hit 3000 rpm's the motor sounds like fuel is cut and backs me down or just stays at 3000 grand like I'm red lining. I have sat down with my tuner and we have been going over all my setting and can't seem to get the motor to rev any higher. The ECU is acting like it's in limp mode and we can't get it out to save our lives. Here are my current VAFC settings ( I already know a lot of people on here dont like VAFC but it was working great with it and will have to do until my AEM FIC gets in):

Sensor Type:
In: 3 Out: 4
Car Select:
Cyl: 6 Thr: Arrow NE
Graph Scale:
PR: 760mmHg
NE: 6000rpm
CR: +_ 3%
Wide Throttle:
Mildly rich
Narrow Throttle:
Mildly rich
VTEC Control:
Low - High: 4800rpm
High - Low: 4200rpm
V/T Unmt ??:
Hi<<L: 0%
Lo<<H: 0%
Throttle Point:
Lo: 25%
Hi: 75%
Nep Hvt:
Ne1: 4000rpm
Ne2: 4500rpm
Ne3: 5000rpm

Re: No rev over 3grand possible limp mode?

Ok. First off, Im pretty sure all honda sensors are 6in, 6out.
Also what is causing the enigne to limp. The rpms, or boost? Its probably boost, because i hardly doubt 3% is enought reduction in the map sensor to trick the ecu.

Hey so still stuck at 3000 rpms I wanted to know if anyone who has Turboed their V6's, had this issue when they first started their cars. I have played with everything on the VAFC and nothing helps. If anyone has any ideas i am in some desperate need of some help, anything would be great.

Ok I don't exactly know what your problem is or have an exact solution to it, since I'm not boosted, but I had the vafcll and the 1st 2 times it was installed it would work fine, until a few minutes later, where the same thing as you described would happen, my car wouldn't rev higher than 3 grand and would just redline there. But then I had someone re-install my vafcll and things worked fine, I think your problem might be the vafc and one of its wires either got loose, or is giving out mixed signals the ecu can't comprehend with. Hope this helps.

maybe you should go get it tuned again......

^he said his tuner couldn't figure it out either

Have you tried creeping it past 3000rpms with very light throttle? or is it only under wot?

I would double check the install of the VAFC as well, good place to start.

I do know that if the ECU sees a weak/intermittent/broken signal from the VSS it will cause a premature fuel cut-off, similar to hitting redline. Wouldn't hurt to double check the VSS and make sure it's connect is fully seated and clean. Again, not sure if VAFC uses this signal at all.

mraw112 said:

^he said his tuner couldn't figure it out either

Click to expand...

Find new tuner.

/thread

mraw112 said:

^he said his tuner couldn't figure it out either

Have you tried creeping it past 3000rpms with very light throttle? or is it only under wot?

Click to expand...

Yes i have under any and all circumstances I get fuel cut at 3000 rpms.

I know that its fuel cut because my AFR's are between 14.3 and 14.9 pre boost and as i start to get into boost I run between 11.5 and like 12.7 AFR's. However as soon as I hit 3106 RPM's the systems leans out and I get AFR's as high as 22-24. Will recheck my connections however they are all soldered in pretty well so we'll see what happens, thanks guys.

Also my original research on MAP sensors showed that I needed a check valve before the sensor so that no boost hits my MAP. Lately though I have been getting a lot of feed back that this check valve may be uneccesary, this doesnt make much sense since I know MAP sensors hate boost and this seems like it would only confuse the MAP more to remove it thanks for any help as always.

*** Got some updated info on AWD conversion (Project Stupid Honda) I will be posting as soon as I get more time ***

Hmm....I had this problem once, symptoms are almost exactly as you described. Had to do with a lack of vacuum. Check your hoses, you may have pinched something.