dohcdelsol37

I've searched online for what this problem could be and I'm not finding any legit answers or problem solvers. hers what's goin on:

I have a d15b bottom end with a complete z6 head, a z6 dizzy, p28 ecu, car hits rev limiter at 6000 rpm.....I've tried multiply dizzys so that's not the problem....I've tried multiply p28 ecus so that's not the problem.....vtec is wired up properly and working....the engine used to b auto and was converted to manual, I don't think that'd b a reason why.....we were thinking it might b fuel injectors, but I'm pretty sure the injectors on a z6 and d15b head r the same......we have run out of options for what could b going on, if anyones has any insight on the problem or has experience the problem ur self and foind a solution, then lmk

hafast

Would like to know as well, pretty much the same setup but its just a d15b stocker, been running it like this for about 2 months never really bothered me cause 7400 rpm is useless in the snow.

dohcdelsol37

lol, very true.....I'm in hawaii and would like to use the full potential of my setup.....my friend and I mayb thought it had something to do with the auto to 5spd swap and that if its an auto p28 ecu, then mayb its trying to look for something from the auto trans, a sensor or something, and not seeing it, so it doesn't let me go over 6000, but id b very surprised if that were true

Wrona

covert your ecu to Manual

dohcdelsol37

I'm actually in tye process of figuring out if I do have an auto ecu or manual ecu, ill get back to y'all and let y'all kno

Wrona

here this should make it easier

92-5 ECUs (P28, P30, P61, P72, P91, P08)
5spd = 000, 001, 002, 003, A00, A01, A02, C00, C01, C02, J00, J01, J02
Auto = J50, J51, 901, 902, C50, C51, C52, A50, A51, A52

dohcdelsol37

yea its manual, p28-a01

owneyboy

iTrader: (1)

is the mechanical timing correct BTW... you dont need to rev past 6000 rpms im sure your car stops making power @ 6,200 anyways

dohcdelsol37

we just double checked the mechanical timing yesterday and its good....we even seen a post about the same issue, they said that if u retarded or advanced the timing by one tooth then it woild fix the problem, but it didn't, same thing happened....our next thijg to try is to look at the vtec solinoid and if its working correctly or not, again another post about the same issue said that the vtec was working correctly......if the car was working correctly, it would produce power over 6200 rpm, not a lot but still some, vtec should engage somewhere around 5200/5300 rpm and then redline at 7200/7300 rpm

HondaPartsHero

I'm confused is it actually hitting a rev limiter at 6k or just not making power? Any check engine lights on? Is VTEC actually engaging? Did you put together the mini me or buy it like that? If you put it together did you remove the oil jet?

dohcdelsol37

its hitting a rev limiter, no CEL, not sure if vtec is engaging....and yes, a buddy and I did it and we knew about taking out the oil jet and did so

1sloEM1

do you have an oil pressure gauge? you may not be getting enough oil pressure to activate vtec. had that issue on my LSVtec. not having the p28 converted to manual very well could be the issue as well.

dohcdelsol37

The p28 ecu I have is a 5spd p28 ecu...I double checked the internals to make sure....don't know bout the oil pressure, guess I can get a gauge and check....does any know how much oil pressure it takes to engage vtec?

HondaPartsHero

Do you have access to an aftermarket tach to check your RPM's? After googling your issue some people have found the stock tach to be off. Just a thought.

dohcdelsol37

I'll have to look into that one, thanks for the info

dohcdelsol37

**UPDATE**

my friend and i (who did the mini me swap) double checked whether we took out the oil squirter or not....turns out we did, so thats not it.....so we are leaning towards the problem that it's the vtec thats not working....cuz from what we understand(correct us if we're wrong anyone), when vtec engages, it works on a differnet fuel map programmed into the ecu and that when the motor is in "non" vtec mode, the fuel is programmed for non vtec fuel map, correct? so if this is true, if vtec never engages, the ecu continues to run the non vtec fuel map and possibly has a fuel cutoff at 6000 rpms for non vtec.....so we are trying "vtec bypass" option....by tapping the 2 pressure switch wires together, the ecu would b tricked into thinking there is oil pressure and therefore when vtec is programmed to engage, it would engage......we will be going for a run in a min, i'll let ya'll kno what happens