1INSANEGTO

iTrader: (13)

Well. Lets start out here. We bought a 2004 GTO from am member here for a really really good price well modded. Well it was tuned before with EFI Live. Well since it had a nitrous kit I wanted to make sure the tune was dead on so I took it to one of our well known local tuners and he pulled the data from the EFI live into hptuners and made some changes and made a few pulls and everything was dead on N/A and with the nitrous.

We took it out on some back roads and made a few N/A passes and nitrous hits. Everything was fine per the AEM wideband. Well the wife wanted all black leather interior so we had a friend to swap with. Well in order to not get a airbag light during the swap which is typical if you do not disconnect the battery. So we disconnected the battery and made the swap.

Well a few days later the car started acting crazy examples.
1. Wideband would go way lean buck and pop when we came to a stop (autocar)
2. Wideband at full throttle would read 10.1 A/F also on nitrous it max it out at 10:1.
3. Lean idel sometimes and sometimes it would idel at 12:1 A/F.

Well we were planning to get it retuned and that would fix it and we were fine as long as you stayed out of the throttle and not beat on it. Well we were coming from the bank one day and it started poping and acting crazy again and stalled. So HPE is really close and I pull in and they put the scanner on and look at my 02's and the passenger side was dead and the drivers one was almost there. I thought uhhhhh makes since this might fix the problem

So I got the unvl 02's which was a mistake so I took those back and got 2 new OEM 02 sensors. Well did the install and guess what? It still did the samething

So I take it back to the tuner and we do some street tuning and he says that the long term and short term fuel trims are adding i think it was the max of 20% fuel and that was the reason for such the rich cond at full throttle. So he makes changes and street tuning is fine and made some changes to full throttle tuning. Well during this time we had a issue with the Vats not sure if its related or what. However everything looks good on the tune and all the cells are in the green vs they were all red before.

Well we drive back to do some pulls and it starts to go crazy bucking and going lean while going through the rpms. Well the long and short term fuel trims start to max out again.

Keep in mind we have his wide band on one bank and my AEM wideband on the other bank and there both reading about the same.

He plays with it for a while and it does not want to do anything. So he flashed it back to OEM and rebuilt a new tune and guess what same crap He even loaded back the tune I came in with. still same crap.

So now we think there is something wrong and something might be hurt. So they checked the following.
Compression Check 150psi in all cylinders (AFR225 heads yes I know there big for stock bore)
Checked fuel pressure to make sure it was not a fuel related issue and the fuel pump was not going out. It check good.
Checked for vac leaks and there were none.
Replaced plugs

Finally after all this the tuner refunded back the $500.00 for the tune and referred me to another tuner cause someone said his cable might be bad or something.

Ok so on my way home on the freeway crusing at 70mph I punch it and watch the wideband 12.5 12.8 13.0 and stays at 13.0 till 100mph. Ok thats fine so nitrous. 70mph 12.5 then the hit and 11.0 so i let out. Ok its too rich.

So I take it too HPE and have chuck take a shot at it and still same crap. Chuck check the following.
Put stock coils on as I had MSD coils. still no change
Chuck thought it might be a valve spring or something so they crap the temp gun and read all the cylinders and there all at temp.

So I leave there now pissed and the wife is even more pissed cause we just bought this car and she can not drive it. So I call steve at SNL and we talk about some problem solving.

So I do the following.

Remove the intake and check for cracks where air might be getting in. there good only thing I did find was it was not tight so I torqued it to spec.

I do notice on the intake that the Map sensor has silcone around it so I dont know where that came from but I cleaned and replaced.

I removed the aftermarket cold air intake tube and put the stock one on thinking it might be sucking in air at the throttle body due to fitment of the cold air intake tube hits the rad.

Checked injector orings and there good.

Checked all wiring and everything is good.

Well I try it again and still same crap.

Now quite pissed at this point. I want to make sure I dont have vac leaks so I get me a can of starting fluid and spray it everywhere and on everything and guess what nothing.

So at this point Chuck@HPE has looked at it and Mike & Joe@G-Force&Sixspeedinc has looked at it and I have got advise from Steve@SNL and we still have a car that runs like crap.

Any advise on what to due now? New PCM? Go back to EFI Live

Doc

iTrader: (9)

I take it you have a FAST intake? If so, does it (the valley cover) have the FAST supplied button style fasteners?

Under the DTCs in the tune, are the Crank Relearn DTCs (P0340,41,42,43)set to report?

What kind of plug wires?

Any logged missfires?

1INSANEGTO

iTrader: (13)

No logged Misfires from Chuck@hpe or Mike@ G-force per there hptuners
MSD wires

I will see if I can get Mike to post the tune as I am sure he wants to know what the problem is and get the tuning money back.

LS1-450

iTrader: (33)

Who's injectors & size? Is it still the returnless fuel system or has it been modified? Pull the fuel pump fuse & the injector wire clips & apply 12v to each injector & see if they click. Also, has the fuel rail ever been cleaned? It can plug up near #7 & #8 cylinders. Any exhaust leaks before the front 02's?

Doc

iTrader: (9)

Fine for a while, then goes to pot... doesn't sound like a tuning issue to me.

I have not had any real success with any wire other than the GM Performance parts wire.

There is no real dtc or indicator from the pcm for a bad wire(s). I have seen real funky problems /symptoms due to faulty wires though.

Frost

iTrader: (45)

bingo. fix the problem, THEN take it to get tuned.

If you drug me around for an afternoon with a hurt car and then wanted a refund I'd balk. I may not charge you the cost of tuning, but it's not OK to use up an afternoon of someone's time for free either...

It's kind of hard to own the cars that you own and not be able to tune them or at least use the scanner yourself. It will be cheaper in the long run.

1INSANEGTO

iTrader: (13)

Stock returnless fuel system.
30lb Ford Redtop Injectors
Fast Fuel Rails

How would I apply the 12v?

1INSANEGTO

iTrader: (13)

I did not ask for a refund. Gforce gave it back to me and I will be using them once the issue is found and also when we redo the heads and add a bigger cam. As far as I am concerned they have earned my business thus far.

The car ran good before the tune and after the tune it started having all these issues. I am asking for feedback and maybe someone here can give me idea's on the problem so I can fix whatever it is and return it back to be tuned.

The car had all the mods performed before we got the car. Here is a list and maybe this might help

Mods.
Afr 225 heads
Fast fuel rails
SVO 30lb injectors
Ext fuel cell and pump for nitrous system.
Fast intake
NW Throttlebody
TNT Power Nitrous Ring
2 Aeroforce gauges rpm, and oil pressure. Other is nitrous but is not hooked up.
AEM wideband
AEM Fuel Pressure
Custom cam (Spec's unknown)
MSD windowswitch
NOS Nitrous Controller with LCD touch screen.

Also I do plan on buying hptuners. I do know the basic's

Frost

iTrader: (45)

Could you get any logs from when the condition was active?


I didn't mean to sound snippy in the other post, I thought you said that you got refunded for all of your "tuning" time

LS1-450

iTrader: (33)

You gotta connect one wire to a 12v power source & one to chasis ground. If you have a voltage meter, you can find a 12v power source w/key on in the under hood fuse box. It's important to eliminate the injectors as an issue. So, this really needs to be done.

Also, many tuners will turn off the DCT code or reduce the sensitivity for the crank sensor when using an after market cam because the cam causes a false missfire code. Am not sure about what is done with the cam sensor, but, am thinking that it is left alone. Anyway, there may be a crank sensor issue that is not throwing a code. The tuner will know if this has been turned off.

I'd also confirm that each coil is indeed firing. I read where different coils were used, but, this doesn't eliminate a PCM problem. Only way I know to check for sure is to start the car & pull a plug wire one @ a time to see if it's firing. Hopefully, someone will chime in with a better way to check. Regardless, it should be checked so that it too can be eliminated.

We need to have a list of everything that has been turned off in the PCM; ie,
rear 02's, Manufacturer codes like crank, air pump.....etc..

Also, there's a lot of nitrous crap on that engine that should be gone through to ensure that it is working correctly & not adding fuel under normal driving conditions.

Please post again once these have been checked.

veee8

iTrader: (40)

What MAF is on the car? Maybe swap it with a KNOWN good one?

Mike TexaSS

iTrader: (2)

I agree.

There is nothing in the pcm that can cause split second massive air/fuel swings. Trims are at around -4 crusing then then the car will start to feel like its misfiring but is fuel related. I had a wideband in both banks of the car and it would swing from 14.7 to 18.0 instantly at the same throttle position! We checked everything. It acts like its a ground issue but all grounds were checked and in their proper places..


Also I tuned the car the week prior to the customer changing his interior and it tuned perfect with no issues. He then had issues I spent almost a full day to try and fix it. And I wrote him a refund check for 500.00 after the tune was perfect the first time! TALK ABOUT CUSTOMER SERVICE!

Wow after typing this and reading it maybe I need a 500.00 refund!

LS1-450

iTrader: (33)

Or just disconnect it & see if the trouble goes away. Stay away from WOT pulls while disconnected. Just disconnect, drive normally & see what happens. It'll throw a MAF code, but, don't worry about that for now.

Does it have a K&N filter or similar. Was it oiled lately?

1INSANEGTO

iTrader: (13)

Truth be told the prev owner said SLP and Mike said it might be a Z06. There is a part # on it ingraved so I can do some research on that also.

HUGGER ORANGE SS

iTrader: (2)

Lots of info here, you guys look like you have checked everything except something simple, Un-plug MAF and run her. A damaged or screwy MAF would cause situations like this. Also have your tuner, tune the car without the maf and see if it does the same thing. Your car should run fine without the MAF, unless your VE tables have been seriously altered.

I've seen this before, it sounds like a MAF situation. LOL I've even had people put too much oil on their K&N Filter and have issues afterward, not that you did that, but something might be amiss with the MAF. People come to me or call, and I ask them the simple question "what have you done in the last few days since the car started acting like this", Retrace your steps, just a process of elimination.
Good luck.

Clint

1INSANEGTO

iTrader: (13)

Clint at this point the MAF I guess would be unknown. The prev owner said it was a SLP and Mike looked at it and confirmed it was not and might be a Z06 Maf but could not confirm. So I will try the methond of running without or seeing if I can find a local stock one and see how the car reacts.

ramairws6

iTrader: (33)

Check the Maf like said above. Also, do you have a timing tuner? I see you have nitros so I assume you have something like this? The reason I ask is that I had an issue of the exact same nature and what happened was the wiring for the Timing tuner melted and grounded against the block down by the crank sensor. Odd but it did the exact same thing yors is doing! Worth a shot? Traver

minytrker

iTrader: (13)

I may have missed it but did you try to run the orignal tune that came in the car again?

LS1-450

iTrader: (33)

Yah, the simple unpluging of the MAF & filter oiling are only noted two posts above yours. 1INSANEGTO, where are you on this?

edcmat-l1

iTrader: (10)

Why dont you find some one with a smoke machine, and smoke the intake?
Also, slow moving 02s will cause what you're experiencing. Seen that many many times.
My moneys on either a vacuum leak, or slow/lazy 02s. If its adding fuel primarily, its either doing so from some skewed input (most likely vacuum/airflow) or its doing it to try and force the 02s high.
A good data log while its doing it ought to give a good indication of what is causing it. Just need to be logging the proper PIDs.
STFT, 02s, man vacuum, airflow (hz), rpm, tps, etc.