Need help from the KA-t Gang!

[Chezedik]

Okay, I am having a very poor running issue (yes she starts), and since I am on a whole different page than Nissan intended, I need some help from people who have been there.

1) For users of the N62 MAFS, what are you reading for MAFS voltage at idle?2)What is everyone getting for idle vacuum (I would guess 15-20"Hg)?3)Is anyone using ROM Editor to modify the program?4)Does anyone have a copy of Consult that will support the function that lets me set the distributor base timing?

I am running so rich the car doesn't want to run well at all, it barely tries to start, and when I get it running it dies before I can get the wideband warm. Please help me.

[nissanfanatic]

1) On initial start up just now, I saw 1.3-1.45v.2) Climate can play into this, but I always see at least 18"hg....3) N/A4) I use Datascan available from http://www.blazt.biz

Any way to pull fuel? You can **** around at idle, your engine isn't gonna blow from messing with idle enrichment..

[Chezedik]

I thought I was showing .6v at idle, so that isn't good, but that should cause a lean condition. I have used Emanage to pull -50 on air flow, and it is barely touching the rich problem.

I was seeing 7"Hg, but that was when I had a valve hung open on #3. That has been fixed, I need to get my boost gauge working again to check.

EDIT: Does DataScan allow for Base Idle Adjustment or just Conzult?

[Craving4Boost]

Datascan does allow for base idle adjustment. I get at least 20inhg vacuum at idle. During the time I had 15inhg, it was a vacuum leak.

[Chezedik]

It is not in a diagnostic format is it? That is, can I "set it and forget it" (Ron Popeil) or is it just an adjustment that is used for problem diagnosis. If it is the prior, that by itself would be work 30 bones. Anyone else care to weigh in on MAFv?

[myRed240]

How long have you been turbo? Is this a recent turbo install or have you been turbo for awhile and now you're having problems?

The only reason I ask is because I'd like to recommend checking your MAF wiring, but if you've been turbo'd for awhile, I don't want to offer help that doesn't apply to this case.

I had an over-fueling problem and couldn't keep my car running because it was dumping so much fuel.

My MAF was wired per the JWT diagram and I found out that the grounds needed to be separated- one to ecu and one to chassis.

[Chezedik]

I am just getting this old girl running. I have each of the MAF wires separated, rather than as JWT describes.

I have been told that which ground goes to the chassis can make a difference, and fix overfueling, but it doesn't make sense to me why this would be the case. A ground is a ground, right?

How significant was your overfueling issue, would the car run and drive? Or was it more like my issue.

[myRed240]

Q: How significant was it?A: My car would not run with the fuel pump fuse in, it would only run with the fuse out and it was a terrible idle. I was spitting fuel out the exhaust and fouling plugs left and right....

All wires are color matched, except the Orange one runs to chassis ground. Once I figure that out, the car ran like a champ.

A B C D E F (Harness)X Wh B Or B/Wh X (Wires)

I hope that helps.

Alex

[nissanfanatic]

Linked to another forum for informational purposes only.

http://www.ka-t.org/forums/vie...round

Thats how you wire it. Scroll down to about half page..

[myRed240]

Does that mean I have my grounds wrong?

[Biggamehit]

thats sounds crazy chezedik

x2 on that ground

i wired my N60 ( same wire up as N62) up without the diagram and got it right. then the other day i said let me run this second ground in series and man that screwed everything up so i clipped it and things were normal again. with my current wire-up, every once in a while i get a crazy idle for a few seconds and its stalls if i don't press the gas. my decel settings are fine and i hardly ever have issues.

ill give the chassis a try and see if it levels out a bit. i had to also play with the sensor type IN and OUT. 3in 5out keeps my car running. what about u guys??????

[coolbone28]

My z32 MAFS reads about 1.35v at idle on a completely cold engine. .46 with the car off but in the "on" position. What would happen if you mixed up the power wire and the signal wire on the MAFS? Also, my vacuum is usually around 20"hg at idle (850rpm) and i am at 4000 elev. When i go lower to like 2000 or less it is usually around 23"hg or so.

[Craving4Boost]

The base idle adjustment only takes effect when the consult board is plugged in. You can't adjust to what you want neither. You just press a buttom and it forces the RPM to idle at 750rpm. does your IACV not work or something?

[nissanfanatic]

Using a conversion, I do about -22"hg..

[Chezedik]

Q: How significant was it?A: My car would not run with the fuel pump fuse in, it would only run with the fuse out and it was a terrible idle. I was spitting fuel out the exhaust and fouling plugs left and right....

That sounds like me all over, and I went to check my MAFS wiring, but I already hid the job (I likes me a clean wiring job), so I will have to cut it back tomorrow and see. Man, this would be perfect. When I use consult to turn off the pump it will start to kick off until line pressure drops to 0, then when I turn it back on, it will try again, then stop. I sure hope you are right.

Craving4Boost, no I meant timing adjustment. But that is okay, the more I have read the more it seems like I may not have any prob with timing right now. Now to figure out what the hell the prob is with the knock sensor. I will let you guys know what is up.

[eazye2000]

What would happen if you mixed up the power wire and the signal wire on the MAFS?

I've done that before by looking at the plug backwards from what the diagram said. If I recall, I think I have like 3.45+- volts with the key on, and not running. There wasn't any IN or OUT that could make it run...

[Chezedik]

I thought it fried the MAF, since it was running 12v through the 5v reference. That's not true apparently...

[WDRacing]

Linked to another forum for informational purposes only. http://www.ka-t.org/forums/vie...round Thats how you wire it. Scroll down to about half page..

I like that diagram...LOL.

Here's what the JWT and the other look in comparison. Basically the same aside from the grounding issue.

[Chezedik]

Sorry guys, the MAF is wired right, but I still think that it is where my problem lies. Does anyone know how to test it off of the car. I would do it on, but I think we all know I cannot get it to start.

[myRed240]

To find out if the MAF is bad, take it out of the loop, ie. unplug it and see how your car runs. It should run without the MAF plugged in.

[WDRacing]

If it were a case of bad maf, then it will run in or out. Limp mode doesn't require the MAF to be removed, just the loss of the MAF signal.

Cheze, do you not have a stock unit to install?

WD

[Chezedik]

No stock unit. Unplugged it still will not start. Also, I am working on an aftermarket ROM. I have two codes that I will chase down tommorrow. One is more significant than the other:

11 - Cam Angle Sensor (the biggie)34 - Knock Sensor

I checked for boost leaks and they were everywhere. I went ahead and tightened everything down (just before my detector blew up). It looks like I may need a new intake gasket, because I have bubbles. Of course, they don't appear until after 30+psi! In any event, I have a new 'Hondata' style intake gasket I will install this weekend.

I will check tomorrow for more boost leaks. Also, I will try to find the problems I have with the two codes. If I get them knocked out, I will be in a better place.

So no one knows of any sort of resistance test on the MAFS to call it good or bad. I know the prevailing wisdom is that the car will run fine with a MAF unplugged, and this will help diagnose it. I have, however, had it happen otherwise.

Also, in case anyone is wondering, my knock maps are the same as my high octane maps, for now.

[WDRacing]

Wish I could help man, I'm rom tune retarded...

[Chezedik]

Nah, it's not in the tune. I have the AFR values, and they are no where near this. I am now operating on different angle. I am looking hard into this CAS thing.

[nissanfanatic]

Test resistance across the 12v and 5vreturn terminals..

See if there is a schematic anywhere in the FSM about the MAFS... That will give you tons more information about it and what to test..

[Chezedik]

I didn't think any of the FSM results would be valid, since I am dealing with a new MAFS, is that not true?

[WDRacing]

Use the 300ZX FSM...

[Chezedik]

Nothing in there about an off the car test, either.

[SeanC]

maybe this will help from all data:1) Pull the rubber insulator back from the air flow meter connector. 2) Turn the ignition switch ON. 3) Using a volt meter, check voltage between terminal B and ground. Voltage should be approximately 0.8 vdc. 4) Start and warm the engine to operating temperature and then idle it. 5) Using a volt meter, check voltage between terminal B and ground. 6) Voltage should be approximately 0.8 - 1.5 vdc. If the meter fails the above test, check the "hot wire" for dust or damage and replace the meter if necessary.

[Chezedik]

That is straight out of the FSM isn't it? Will that work given that I am running a different FSM? I will happily do it if you think so. I am getting close to losing it.

EDIT: Also, I cannot get the engine running and warm to do this test.
Modified by Chezedik at 12:11 PM 3/2/2007