Won't rev past 2500, no codes..

[goofynick6]

So, is my MAF wiring bad? the MAF itself bad? Or do I have leaks after the maf?

I wasn't sure if the leaks would cause it to have a rev limiter at 2500 rpm..

I'm getting only code 55, so I'm thinking wiring to maf maybe? I extended them, but who knows where they could be wrong...ya know?

Any opinions?

Thanks,Nick

:help

[accel junky]

I wonder if I'll run into the same problem.

I used the q45 maf, and wired it based on the letters on the maf, and meggalas article.

Check your maf wiring out on http://www.meggala.com/partcss.htm

Scroll midways down. That should straighten you out if there are any problems.

Though I wish there was some info from this page on the q45, but I just based it off of the wiring labels from the z32 on this site.

[frosted flakes]

yeah its the maf...i also accidently unplugged the MAF on my rb20det and it wouldnt rev past 2.5k rpm...it sorted acted as a rev limiter...yes that is defintley your problem right there

[goofynick6]

I have double checked the maf wiring according to rb20det.com and it looks right; even used shielded wire.

Anyone know how to test a z32 maf..

Nick

[JonPowell]

Here is the procedure for the RB25 MAF

Key on, engine not running MAF signal should be .3VCranking the engine, not running should be 1.0VEngine idling should be 1.1V

This is on the wire leading to the ECU carrying the signal.

[goofynick6]

I have a z32 maf.

I started the car with the maf not hooked to the intake of the turbo..and it ran the same, then I unplugged it and it ran the same.

The ground wire on the plug has continuity all the way to the ecu as does the signal wire. The power wire has 12v and the other ground (chassis ground) I have yet to check.

So, I'm thinking the maf itself is bad, but there is no code...so could it be air leaks? I had one leak in my custom intake manifold that wasn't too big, but I feel like it wouldn't have a 2500 rpm rev limiter for a leak..

Any thoughts?

Nick

[JonPowell]

Its not really a rev limiter for leaks, its just that the ECU has no idea how much air is flowing and is freaking out. It is for the MAF not giving it a signal. If you have a Z32 MAF that worked before, your ECU is probably reprogrammed to throw no code for MAF problems...since the Z32 MAF on the stock Rb25DET system IS a problem(to the ECU at least)

[goofynick6]

Turns out I had a short of some kind on the maf signal wire.

Fixed that and it was better, revs up, but now it just feels slow to accelerate, like it's hesitating, and then once it hits boost it takes off fast. I think the eprom chip I burned must be wrong, and it is thinking it has an rb20 maf instead of this z32.

Getting closer......what an uphill struggle!

[Wulfgang]

Devil is in the details.

[goofynick6]

Ok, something new to try tomorrow. The K constant I had programmed for the injectors was way off and giving 60% less fuel than required (so we think).

WIll post back tomorrow with results.

Nick

[JonPowell]

Engine go BOOM!

[goofynick6]

OK...

Now I'm running like 12-13:1 ratio at idle..heh. I'll get it soon.

However, I now realize I have transmission problems and will be making a post for that now...I need help!

Nick