View Full Version : misfire/hesitation @ 2500 rpm...rev cut?

07-21-2008, 02:08 PM
so i just got my RB25 goin, and it's roadworthy now so i've taken it for a few test drives up and down the street.

However, as soon as the revs get to 3.5k (according to tach...so more like 2333rpm actual) it feels like i'm hitting a rev limiter. I know that if there's a code on the ECU it goes into "safe mode", limiting revs at like 3k. But i checked the codes on the ECU and i got code 55 (all good)

I put in my walbro 255....same thing. Brand new plugs, gapped properly, and it runs smooth as eggs up until it cuts out and stutters...

any suggestions?

07-21-2008, 02:50 PM
Check your MAF, that sounds like the classic messed up MAF problem.

07-21-2008, 03:18 PM
wouldn't that throw a code though? I bought the MAF used, but it looks mint, and it's really clean

i should add, its not so much a misfire as it is like a rev limit/fuel cut. there's no possible way to get past the hesitation, it simply bounces right at 3500

07-21-2008, 03:46 PM
what MAF you using? mine did the same thing. it was the maf.

07-21-2008, 06:18 PM
it's the stock maf.....can't remember the code exactly e60 or somethin???? I'll go out and take a look at it again. did yours throw any codes?? Or how did you diagnose it was the maf?

07-21-2008, 06:38 PM
ok, i'm thinking u guys are right. it does the exact same thing when the maf is disconnected.

it is in fact an e60 (stock maf for a series 2 rb25)

it looks so perfect....i'll double check my wiring...but i'm sure its right. I was completely sober when i did it

looks like i'll be looking for another! thanks guys

07-21-2008, 07:49 PM
well wtf do i know?!?!?! My wiring was bad. Although i had everything wired correctly....almost there are two wires shielded by wire strands and another layer of insulation....and although i soldered them together, i forgot to wrap them each in tape!! I just wrapped the whole thing up so they were touching. I feel like a dumbass but it's a hell of a lot better than buying a new MAF! car runs pretty nice now...already got yelled at by an old bitch who lives down the street. apparently 30mph is much too fast for my little dead end. thanks fellas

07-22-2008, 10:03 PM
no problem, glad we can help