This is kind of a continuation of a post I placed earlier as I have some new info. I posted that I have a studder at 3000-4000 rpms that feels like I am hitting a rev limiter. Above 4000 it pulls hard with good A/F's. I am using an MSD ignition system, and that it only happens at WOT. A/F's look pretty good, and this problem just started happening a couple of days ago, on the same tune that I have had no problems with prior. I have since pulled the plugs, and they look like sh@# compared to the plugs I pulled out a couple of day prior to the problems. The plugs are reading very rich. I tested the TPS and it was fine, and I tested the MAP sensor, and it's voltage was off, but seemed ok. One question is at idle my factory map sensor is reading -768mm/hg and my e-01 is reading -420mm/hg. Could that mean that my map sensor is bad?? Could the map sensor be causing this issue. Again it's only at WOT, it does it under load, and free revving. I have a hunch that it's more timing related, but just seeing what you guys think. Thanks

 

If the MAP sensor is reading HIGHER than what your EMS is reading (which is what it's basing your fuel/ignition maps off of), then yes you'll be running off tune.

What else did you change between the time it was running well, and now? And what voltage range was your TPS sensor testing at? If I recall, it should be 0.5v - 4.5v or so from idle to WOT.

 

The TPS is reading .45-4.6 idle to WOT. So it's ok. The oem map sensor is reading approx. -27 in/hg at idle, and the e-01 is reading approx. -15in/hg at idle. I know that that's kind of weird, but the thing that has me so baffeled is that it is always around 4000 rpm, and only that rpm, and only at WOT. I agree that the map sensor could be off or bad, but I would think that if that were the case that #1 I would get a CEL, and #2 it would go into limp mode and run like crap from 4000 on. If I roll out slowly in 1st gear (1st gear is the most violent) and hit WOT from about 1000rpms it pulls hard until it hits approx. 4000 then it sounds and feels like the the MSD box is engaging the soft touch rev limiter, then shortly after that it lets go and pulls really hard (like normal) all the way to redline with no detonation, lean burn, overly rich, high egt, or anything weird. I do have one theory that I will have to test out tonight, and that is that I have a MSD 2 step installed as well with a 4400 rpm pill for the launch, and 8000 for redline, and I wonder if it has failed and is trying to engage both redlines. My momentary switch definately selects the lower RPM pill like it is supposed to, but I guess I'm just hoping for a "there it is!!" kind of solution. Let me know what you think, Thanks

 

Also, do you know if it is possible to use a 3bar map sensor with the factory honda computer? I checked the one for my e-01 and it seems to be on the same volt scale, but they are WAY cheaper than OEM.

 

Have you tried removing the MSD box altogther?

 

Not yet, I don't have the factory stuff anymore. I'll start eliminating things tonight. I have a friend that has the same car, and he's going to let me use his map sensor to see if that fixes it. The first thing I'm going to do that will take 30sec is to unplug the 2 step and just put the 8000rpm pill in the MSD box. Thanks for the help though.