Hi,

I am currently running a built 3.8 twin turbo. Got the Haltech a while back and have recently started experiencing an issue. When I'm under wide open throttle and start getting into a peak power band my engine cuts out, it goes into an idol kinda mode and am not sure whats happening. I have to switch off the car and wait for about 30 seconds. Turn the car on and then everything is fine again.

If anyone has experienced this kind of issue please assist.

thank you
DDD

 

boost cut?

 

It sound like your ride may be going into "safe mode". Remember that the Nissan ECU is still in charge of your of the electronic throttle control.

 

You running a MAF?

 

Kind of hard to figure out anything with so little information to go on... Who is your builder/tuner? Hooking up a laptop to the Haltech see what is going on might be a wee bit helpful. Reading the CEL codes, if any, might be another good idea. Good luck.

 

EQUATION
$ (to much money) + to time to try tune the engine = HALTECH

_= (equivalent) to PROBLEMS!! (without technical support)

 

i dont think that reply was necessary

 

Am not sure what a maf is. Since this problem is not consistent am gettin a new tune from a good shop. Will update, thank u 4 the interest.

 

The stock computer controls the throttle body, and there is something upsetting it. You need to pull the CEL codes and see what is causing it.

 

It's probably cheaper to fly Hal out there to get your tune right and the car running solid than it is to pay for custom tuning again and again till they get it right.

Hal has the knowledge and the software to make things work. I'd atleast consider it.

 

I'm having the exact same problem, with a totally different setup! I have not been able to find the solution, but I have a suggestion from Technosquare that seems plausible and the symptoms match exactly.

FYI, I'm running the Pro-EFI 48 PIN and Technosquare reflash to raise the rev limit. I have an SGP built longblock and Greddy TT. The problem did not start until I did the reflash, so we keep thinking it is related. I had them redo the reflash and only adjust the rev limit (originally they did other stuff). It is still doing the same thing. I have had Jason from Pro-EFI look at the car, as well as Tony from UMS. Neither of them find anything wrong with my programming on the Pro-EFI. Tadashi at Technosquare says it is a common problem when the MAF gives a voltage reading over 4.75. He said there are a few different devices that will limit/control the voltage reading going from the MAF to the stock ECU. The one he mentioned is the HKS FCD (Fuel Cut Defensor), but I can't find anywhere to get it and UMS couldn't find one to get me either.

Anyone else have any feedback or advise on this? I am dying to get this resolved.

 

MRG, it sounds like you have the best working on it for your situation. If Jason can't figure it out, not sure who can. Does your proefi not have a maf-clamp function? And have you checked for codes and the actual throttle body?

 

The Pro-EFI does not come with a clamp. Technosquare was very surprised by this, but Jason says it shouldn't need it. I'm really not sure at this point if there is some type of clamp that I could order for it. Any advice on where to look or what might work?

The car does not throw any CEL when this happens. This also is perfectly in line with what Tadashi at TechnoSquare told me. He said it is not a matter of going into a fail safe mode, but rather the stock ECU does not have parameters at all under these conditions. The programmers at Nissan failed to create any tables for these higher voltage readings, so the system just doesn't know what to do and shuts off. I can tell it is not cutting fuel, either, since the car smells very rich when it happens. It sounds like the OP is having the exact same issue, so if we figure out the solution, it should work for both of us, even though the systems used are different.

 

^ If that really is the case, it is an easy fix for doomsdaydonkey. Scale down the Haltech 'MAF Limit' table. This limits the maximum airflow reading for a given RPM. MRG, do you still have any need to for the MAF - why not disable it?

 

That is a very good idea for Doomsdaydonkey to try, if it doesn't hurt anything else. His symptoms sound exactly like mine, so it is likely the same problem I have. I am only 90% certain that the MAF voltage reading is the problem, though.

I am not sure about the MAF. At one point it was removed, and we were told to put it back on. I'll ask Jason if we can remove it. Thanks for the advice.

BTW, I think your website shows the HKS FCD as something you carry. Do you have these and do you think it would resolve the issue?

 

I have not used them personally but I was under the impression the FCD and comparable Greddy product are for overboost situations on stock turbo cars with a MAP limit.

 

That makes sense. Also, because it isn't actually cutting fuel, I guess it probably wouldn't help. I just didn't know exactly what it does.

I'll take the route of asking to remove the MAF and see where that leads.

 

Be careful w/ removal of the MAF on a 5AT. I've read that the MAF is used to generate "calculated load" and absence of that signal may mess up the % load signal sent from the stock ECU to the TCM. It's one of those 5AT specific quirks that make running without the stock ECU problematic (until someone finally cracks the TCM programming).

I don't know exactly what is going on here, but you could ask the UpRev folks for some help. I've had no trouble with the Haltech on my 2004.5 5at G35 and I've flashed the stock ECU many times (via Osiris).

 

Ah yes, I had already forgotten you said that Raj. Thanks for sharing.

 

what are you talking about? i've seen Hal answer almost all Haltech questions and he works for Injected..