Argh... Need some diagnostic help, G / Z owners.

[AZhitman]

I've been battling an issue on my G for over 2 weeks now, and I think it's about to get the best of me.

03 G35 6MT, Vortech s/c kit, tuned, headers, nismo exhaust, blah blah blah.

Couple weeks ago, it starts "missing" on acceleration (like a dead spot in the rpm range). I limp it home, start troubleshooting.

No boost leaks. Took off plenum and re-sealed it. Throttle body cleaned and re-sealed, all lines good, new plugs, no other obvious causes.

Car will start, then immediately dies. Throttle input won't keep it running, it stalls as soon as the engine fires.

Checked power and ground at MAF, all good. Ohmed the temp sensor, all good.

I cleared the codes, started it a few times until it picked up the codes again, and got P0102 and P0113 (MAFS and IATS - which are both incorporated in the same unit).

Disconnecting the MAFS, however, doesn't change the behavior.

I'm at a loss, guys. Brainstorm a homey outta this problem?

[infinitgkid]

You got me bro, everything I was going to suggest you listed off already...

I donno what to tell you...

When you said missing on acceleration, first thought came to mind was the throttle body, but you already knocked that one out...

sorry

[AZhitman]

Could be the TPS, but that's been replaced twice under warranty...

[Tampa G35 Sedan 6MT]

you see a pattern? maybe it is the same thing? !

[telcoman]

Disconnecting the MAFS, however, doesn't change the behavior.

If no change wouldn't that indicate a problem?

Take it to the dealer & let them figure it out while you drive a new one

Telcoman

[infinitgkid]

you see a pattern? maybe it is the same thing? !

+1

[zozoka1212]

It reads I believe low intake. Which with your system could be anything. Have you cleaned your maf sensor. Also have you cleaned your intake. Maybe did you put some oil on it. Damn MAF is sensitive as hell.Most likely your ECU was upgraded to the Vortech system. Maybe that has something to do with it.

zozo

[Jacko3]

I agree! This issue has something to do with your MAF or an auxilliary component attached to the MAF. This is why i will never oil a JWT pop charger myself. I will just buy a new one every six months and give away the old one to anyone who wants it.

[RED_DET]

Time for a new MAF. If you unplugged the MAF and received no change, then something is wrong with the unit.

[BrandAidDesignG35]

Time for a new MAF. If you unplugged the MAF and received no change, then something is wrong with the unit.

1+

When I installed my intake, I kinda bumped / scratched my MAF, it was kinda missing and stuff for a while, I cleaned it up, works great now!!!! Good luck, but I think they come in around 400?

[SteveTheTech]

Definitely sounds like it might be a MAF. I'm confused that it doesn't improve when it's disconnected, That however will through a first trip DTC and cause the throttle body to go into fail safe since the engine has no idea how much air it's intaking.

I don't know what you have for a scanner but if you can look at your engine parameters see what your calculated load and grams per second reading should be. The output voltage may be a good indicator but CAL/LD and GRMS/SEC are much more accurate in diagnosing a bad sensor.

[gwoods]

I've been battling an issue on my G for over 2 weeks now, and I think it's about to get the best of me.

03 G35 6MT, Vortech s/c kit, tuned, headers, nismo exhaust, blah blah blah.

Couple weeks ago, it starts "missing" on acceleration (like a dead spot in the rpm range). I limp it home, start troubleshooting.

No boost leaks. Took off plenum and re-sealed it. Throttle body cleaned and re-sealed, all lines good, new plugs, no other obvious causes.

Car will start, then immediately dies. Throttle input won't keep it running, it stalls as soon as the engine fires.

Checked power and ground at MAF, all good. Ohmed the temp sensor, all good.

I cleared the codes, started it a few times until it picked up the codes again, and got P0102 and P0113 (MAFS and IATS - which are both incorporated in the same unit).

Disconnecting the MAFS, however, doesn't change the behavior.

I'm at a loss, guys. Brainstorm a homey outta this problem?

Find a member with a 03 swap in his Mafs and see what happens??

Are my 07 Mass air flow sensors (2) the same as your 03? I could be at your place in 30 min to trouble shoot.

[SteveTheTech]

Highly doubtful but it might work. I cannot find the wiring diagram for the MAF on the 07 Sedan since Nissan switched to HTML based wiring diagrams.

[gwoods]

Highly doubtful but it might work. I cannot find the wiring diagram for the MAF on the 07 Sedan since Nissan switched to HTML based wiring diagrams.

Someone with a 03 should be able to help him trouble shoot by swapping parts though right?

What do you think would cause him to keep blowing MAFS? Short? Bad ground? boosted creates higher then acceptable voltage range

[AZhitman]

OK, update:

Swapped in a known good MAF. No change.

Car stalls immediately.

Removal of the MAF results in the car starting and running, but in "limp mode".

Checked continuity on all MAF wiring to ECU - Good.

At this point, I'm leaning towards one of two things:

1) The split-second box (which intercepts MAF, crank and cam angle sensor input) has gone bad.

2) The split-second box somehow "lost" its tune during the dead battery / battery swap.

All else seems intact and functional.

I'm seriously thinking of pulling the SS box, swapping in a UTEC and re-tuning, but that's a big chunk of change.

[zozoka1212]

If you had a dead battery I would say it reset itself or erased samething.Just a guess.

zozo

[SteveTheTech]

What is the Split Second Box?

[gwoods]

What is the Split Second Box?

Piggy back controller, lets the user change the voltage return values of various sensors.http://www.splitsec.com/

We used Perfect Power in the Hemi worldhttp://www.perfectpower.com/

[SteveTheTech]

Huh that's neat. good to know that's, pardon my ignorance. I know that Factory stuff inside and out but the aftermarket stuff gets me sometimes.

Thanks for not burning me.

[gwoods]

Huh that's neat. good to know that's, pardon my ignorance. I know that Factory stuff inside and out but the aftermarket stuff gets me sometimes.

Thanks for not burning me.

No problem man,

Its really cool stuff lets your factory sensors work in boosted/stroked applications. The downside is when it doesn't work your on your own. On the Hemi's we were using it on 260+ cams because the trucks would stall at idle if you couldn't add timing and fuel. There were a few turbo and sc trucks running around with PP too. I just had a 6.1 Hemi cam in my 5.7 hemi so I didn't need the piggy back.

If I remember correctly a lot of Hemi guys had problems with split second sorry hitman.

[SteveTheTech]

That's pretty wild I had been wondering what the effects of forced induction or increased/decreased displacement would have on a factory ECM since that would alter signal parameters.

[gwoods]

2) The split-second box somehow "lost" its tune during the dead battery / battery swap.

Did you have a 9 volt battery backup on your split-second?

if not I think you just solved the problem, your tune is GONE!

[SteveTheTech]

How hard is it to retune one of those?

From what the website says it looks pretty straight forward. Just time consuming.

Damn*t I keep asking stupid questions.

[gwoods]

Should just need a laptop to tune it, but if hitman didn't do his own tune and didn't write down the values he would be tuning in the dark, could lead to a lean condition.

[SteveTheTech]

Oh ok I was not sure which model he is currently using. I was not sure if it was the manual adjustment one. I guess I have not made it that far through the page yet.

It's hard managing my NICO addiction and football.

I'm starting to feel the itch to build something, I am sure the wife will fix that.

[gwoods]

If he had the adjust on the fly model, dead battery would not hurt it.

I bet when they did the install they didn't hook up the 9 volt backup.

Just wait until work tomorrow? or you could come down to AZ and finish my Jeep?

[SteveTheTech]

Yeah that makes perfect sence, at first I thought he might have had the manual one, thus the confusion had not read about the adjustable one. Is it made for Infinitis or just generic?

Yeah wait for work lol that's a joke. It's not only slow its not quite a challenge. I'm putting my time in here till I can hopefully move up to a DTS position or something corporate where I can stay clean all day.

What kind of Jeep are you building?

[gwoods]

1965 CJ-5 with a roller 327 small block...

I have not worked on it in about 6 years LOL. Just sits in my garage waiting for someday to come.

Needs brakes, cooling, exhaust, fuel, electric

Motor/transmission is installed

thread JACK

[SteveTheTech]

Patience is the key to any good project. You want to make sure it's done right the first time.

Are you building an off-road machine?

I had a CJ-7 when I was a teen and had huge dreams but painfully limited funds so it turned into a tax right off.

You have the hard work done already. Motor and trans are usually the biggest pain in the a*s. The brakes and electrical are pretty easy something like a CJ-5 there cannot be more than 5 fuses, and if you are doing a complete re wire there is tons of space to access everything.

[gwoods]

Complete rewire, have a "painless wiring kit"

The snag is I converted from 1965 brakes and clutch to 1990 Wrangler hung pedals and hydro clutch and brakes. I'm not very good at fabricating.

I want to take it to a shop and let them finish the brakes and clutch for me. I can finish it myself from there. I had a company make me some braided brake lines last year that are supposed to go from 1990 Wrangler to 1965 CJ but to put them on I have to completely disassemble the front hubs. I broke my air compressor and every thing is RUST. I am thinking about swapping in 1990 Wrangler front and rear axels and solve a few problems all at once. For example the CJ drums are 9" at all for corners and designed to stop a 72 hp 4 banger. I actually have a Dana 35 from a Wrangler in my garage I just need to move the spring perches over.

I want a rock buggy that is fun to drive on the street. I'd also like to be able to run at the track but the wheel base is so short I'd be scared to go much faster then 90 MPH. I have over 7k in receipts for the motor desk top dyno says 350 hp 420 torque. 2 guys can pick up the rear end... it weighs less then 2000 lbs. The Motors balancer rests directly over the front axle its almost mid engine LOL
Modified by gwoods at 5:54 PM 9/14/2008