iansw

iTrader: (7)

As some of you know - I've been trying to get the Z32 MAF to work with my SC Setup because I am at that point right now to where at high RPM the A32 MAF doesn't cut it.

Well, I've been trying for weeks to make the Z32 MAF work. Tested it on a 300zx TT and it's good - Z32 EEPROM appears to work fine. Checked the wiring against Stephen Max'es and delios wiring - and it is correct. 3 weeks ago I tried it with the correct wiring and it worked well at idle and then would buck at 4k RPM bad.

So today I put it all back in and tried to give it another try under the theory that my belt was slipping (unbeknownst to me at the time) when it was bucking at 4k RPM.

Belt is fixed now - so like I said - I tried it again. Now it's idling like crap and it's super rich. MAF reads 1.2v at idle vs .90-1.0v on the A32 MAF.

So the question is - I'm frustrated with this. Can I just put the A32 MAF on and use a Cartech to control A/F at high RPM instead of the MAF on the JWT ECU?

<I have 300zx Injectors>

IanS

[maxi-overdose]

iTrader: (3)

first of all...Ian, congrats on hitting >300whp. I havent been in this forum for a while.

if your car's bogging at higher rpm, have you verified whether the car is running lean or rich?

so you plan to use the A32 MAF with cartech, will you kept the JWT ECU in there? If so, it's worth to give it a try because the A32 MAF reads lower and you can compensate the fuel loss with cartech FMU. but again, you will need to fine tune the FMU to get the right AFR. Isnt MardigrasMax running a 3:1 FMU with A32 MAF and 300zxTT injectors?

idling problem. What's the Z32 MAF voltage spec @ idle? if it is also 1.2v, then my guess the cause of running super rich at idle can be from your hi-pressure fuel pump, you can verify it by unplugging the vacuum hose to the fuel pressure regulator to see if your engine will be flooded with fuel and die.

good luck

iansw

iTrader: (7)

The car only bogs at high RPM with the Z32 MAF on - and that's not really "high" RPM - it's 3500-4000RPM. That was what i originally was trying to take a closer look at yesterday by putting the Z32 MAF back on - but since it idled like crap this time <it didn't last time> - I never got to test it.

With the A32 MAF, the car runs great, but I'm leaning out up top pretty bad and frankly it scares me....although my EGT's are good and I have heard no detonation - yet. Now that summer is here and it's hotter out I figure I'd better get this solved.
See the A/F Ratio from my last Dyno - http://www.cyberhub.net/dyno/041604a.jpg
<Blue line is with JWT ECU running map, Red is in "Safe Mode" right after a reset.>

I was considering the Fuel pressure thing last night. However - last time I ran the Z32 MAF, I was at the same FP and it idled fine. Not sure what the voltage SHOULD be for the Z32 MAF at idle....can't find any specs on it. Maybe soemone will see this and report what they're seeing.

Pretty frustrating since it worked once, then with no variables changed, it didn't work the second time.

I would be keeping the JWT ECU in and running the Cartech tuned only to control A/F at high RPM.

So are you saying it should work?

IanS

[maxi-overdose]

iTrader: (3)

I think it should. the purpose of this test is just to enrich the AFR at high rpm. if so, you should add more fuel with this method.

btw, what's the "safe mode" you were running on your dyno. I just took a look on your dyno, seems the AFR is a lot better with the safe mode. I would try to go with the safe mode with cartech at a low ratio to see if you are able to bring down the AFR.

iansw

iTrader: (7)

Safe mode being I reset the ECU. After about 60 miles, it goes back to what the blue line shows. So it's not usable as a long-term option.

Also, in "safe mode" I run extra rich down low, and lose considerable low-end power.

iansw

iTrader: (7)

bumpitybumpbump

MardiGrasMax

iTrader: (14)

What Spark Plugs?
What heat Range?
What are your plugs gapped at?

slimer

iTrader: (13)

yeah, i had some gapping issues when i was trying to diagnose my 1st fuel problem (inline not working)

regapped them and got about 400 more rpm until i ran lean.

iansw

iTrader: (7)

NGK BKR611-E <Copper>
Gapped to .036 if I remember correctly.

IanS

MardiGrasMax

iTrader: (14)

Try .030 gap

iansw

iTrader: (7)

Well, adjusting the AFC to very rich limits (+60%) doesn't change a thing above 6k RPM.

So I'm sure it's the MAF. I'll re-gap the plugs anyway - but it won't solve the problem, I'm sure....just maybe help a tiny bit.

I guess I'll try the Cartech and see what I get.

IanS

Stephen Max

iTrader: (59)

To answer your original question, Ian, yes you can run a Cartech fmu along with the JWT ecu. I am doing just that right now. I have the fmu adjusted so that it starts adding additional fuel pressure at higher boost pressures while leaving the rise rate at 1:1 at the lower boost levels. For some reason JWT programmed my ecu to give me 12.5:1 afr, and I wanted to run a little richer than that at high rpm. The nice thing about the Cartech unit is that it is so tuneable, unlike the Vortech fmu.

maximase86

iTrader: (24)

Stephen, when up top, what do you have your a/f set at with the cartech?

S

michaelnyden

iTrader: (15)

wait, iansw, did you get the jwt ecu prog with the S/C and Z32 maf option? maybe that is your problem? if you did get it programmed in there, what happens if you go with the A32 maf again...will that cause issues?

so with a SAFC, you can't just tune the A/F to go richer up in the high rpm's to compensate for the power you are making up there which exceeds the A32 maf? doesn't a SAFC allow you to start increasing A/F at particular RPM's?

iansw, at what point did the A32 maf crap out? couldn't you just have called JWT and had them put in the A/F ratios you want based on the highest hp you think you will end up with?
how did you know the A32 maf crapped out? the more power you added, the more it leaned out up top?

iansw

iTrader: (7)

I have 2 ECU chips. 1 for Z32 MAF + 370cc's and one for A32 MAF + 370cc's.

With the A32 MAF + 370cc program running and the A32 MAF hooked up, the car runs fine, but leans out up top.

With the Z32 MAF + 370cc program and the Z32 MAF hooked up, the car idles very badly and bogs horribly at 3500-4500RPM.

with teh Z32 MAF +370cc program and the A32 MAF hooked up, the car barely runs at all.

Stephen Max

iTrader: (59)

I'm tuning to 11.5:1 above 5500 rpm.

Prodeje79

so it is not possible that they sent you a "bad" z32 maf rom?
Maybe they sent you a cobra maf or a32 maf coding by mistake?

iansw

iTrader: (7)

That's a possibility - the chip I have is for a 1996 Maxima and my ECU is a 95. But it shouldn't make a difference in A/F since the 95-96 ECU's are all the same as far as the AMF and Fuel control go.

I bought it used from soenone on the .org.

michaelnyden

iTrader: (15)

iansw..did you figure out this issue? did you just use the cartech to rich up your mixture after a certain rpm? what A/F did you rich it out to? what was the setting on the cartech?

iansw

iTrader: (7)

Nope - haven't worked on it at all - been too busy.

I have to pass emmissions next month by changing a bunch of stuff in thecar aorund - so maybe after I do that when putting it back together I'll try.

IanS

IceY2K1

iTrader: (3)

Those 2-things *STILL* make me think that Z32 PROM is fishy.

I'd send that PROM to Clark@JWT to have him confirm what program really is burned on it and whether that will work with your '95 auto ECU.

There are SEVERAL '95 auto ECU part numbers and ONE '96 auto ECU part number AT LEAST on JWTs website. There *COULD* be a difference in PROMs that JWT knows about.

My guesses in priority are:

1)Wrong or bad Z32 PROM.
OR
2)Incorrect Z32 MAF wiring.

I'd call up Clark and see what he has to say about compatibility with your '95 ECU part number and a '96 PROM first.

Are you sure the '96 PROM is for an automatic?

iansw

iTrader: (7)

Well, the wiring has been checked and re-checked - Stephen even posted pics of his wiring for me to verify and it was discussed at full length. It turned out that the first time I tried the wiring was actually wrong.

The second time I tried the wiring was right and the car idled PERFECTLY but when boosting it would bog hard between 3500-4500RPM.

The third time I changed nothing at all, and it idled like crap.

Then tested on a 300zx TT and the MAF worked fine.

It's a 5spd ECU, BTW....my car was once auto but now the A32 MAF programmed ECU is 5spd, and so is the Z32 EEPROM. Car runs great with the A32 SC Program. Car also runs great with a 97 5spd ECU I have without the Injectors or SC installed (stock injectors).

The 96 EEPROM in a 95 ECU might be something, but that doesn't explain why it idled perfect one day and bad the next.

IceY2K1

iTrader: (3)

That's about all I can come up with...maybe someone else will toss in some ideas and jog loose something.

Sounds like you've got all your bases covered...I don't know what else it could be.

Curious to find out once you solve it though.