Fuel Cut #2

sleepydsm · 10-24-2005

I have a few questions:

1) I have MAF Translator v1.3 The third dipswitch from the left is fuel cut on/off. It is currently in the lower position. Is this fuel cut on or off?

2)Cruising on the highway, if I drop it intho 4th and go to WOT, at about 4500rpm I get a quick jerk/pop/miss (along with a little poof of smoke) and if I keep on it, it happens again at 5500rpm This does not happen at all if I do a pull from a standing start at WOT. If I take off in 1st and floor it through the gears I don't get the pop/jerk/miss.

In the past week or so I have asked many similiar questions, and I appologize for that. I am really stumped here, and thats why I'm looking for help from all of you who have a lot more knowledge than me! I'm trying to learn just like everyone else, and this is just part of that. So again, thanks all for your input!
-Kevin

For the 10,000th time:
BR 20g
HKS external WG
660cc injectors
255hp
afpr
3" gm maf
maft
5 knob afc
fmic
exhaust
MBC
greddy type rs

sleepydsm · 10-27-2005

bump. I am getting fuel cut for sure. I thought the MAFT took care of that?

**Shane@DBPerformance** · 10-27-2005

How could it? Fuel cut is programmed into the ECU. Unless you change the program inside the ECU, it will always be there. The only way the MAFT could keep you from hitting fuel cut, is if it doesn't report enough airflow to the ECU to keep the ECU from going into fuel cut mode. That could have the very bad side effect of you running too lean. Most people don't mess with the fuel cut stuff on the MAFT because it is a junk option.

dsm10sec · 10-27-2005

Initial setup:

Set the MODE switch to match the vehicle configuration.

MODE SWITCH: set as follows
1 - OFF for 3” MAF ON for 3.5” MAF
2 - OFF for a 1G (90 - 94) vehicle ON for a 2G (95 - 99) vehicle
3 - OFF for NO Fuel Cut Limiter, ON to PREVENT FUEL CUT
4 - OFF for Flat AUX fuel control, ON for Contoured AUX fuel mode.

BOVADDICT · 10-27-2005

I have that problem too. Went away when i turned my boost down. Stock turbo and injectors for me though. I have the maft setup though too, ill try messing with those switches though. Right now everything is on 0 and turned off because again i don't know tuning.

EclipseGST · 10-27-2005

Boost leak test results please!

TheBlizzard · 10-27-2005

I had the same problem in my Laser. When the boost was down it didn't do it, when it was up it did it only when it was colder out. I could never really figure out why it did it but I highly doubt it is fuel cut.

**JET** · 10-27-2005

You will know if it is fuel cut. It is not a pop/miss. All of a sudden you lose all power and you will plant your face in the steering wheel if you aren't careful. It is very violent. This just sounds like a miss and you need to do some tuning. I don't see a logger anywhere on that list. If you don't have one, just stop posting or someone is likely to ban you.

slowbubblecar · 10-27-2005

with fuel cut, it will feel like you are going, then jerk (not go anywhere) and keep going again if you keep on it. It would go back and forth if that is the problem. Paintballpro-you don't have fuel cut. It could be the same problem he has, but it feels like a misfire or a really bad tune on your car.

sleepydsm · 10-27-2005

Quote:

Originally Posted by slowbubblecar

with fuel cut, it will feel like you are going, then jerk (not go anywhere) and keep going again if you keep on it. It would go back and forth if that is the problem. Paintballpro-you don't have fuel cut. It could be the same problem he has, but it feels like a misfire or a really bad tune on your car.

That is it exactly. And I have the instructions for my maf, it is set correctly, and I am not using that for adjusting. Its set for 650cc injectors, 3" gm maf, etc. I was just looking for a way to get around fuel cut, so I could run higher boost. And at first I was trying to confirm that it was fuel cut. The tuning I have done using the AFC isnt that bad, from a dig I can launch the car and go through all the gears fine without that "fuel cut" issue, and it pulls nicely with 0 knock. Also there are no boost leaks.

I'm sorry guys, I am trying to learn here. Please understand that I don't know much yet! Again, thanks for all the input. I guess the boost is gonna stay down, and the car is gonna stay "slow".

A//// Guy · 10-27-2005

The only way to get around it is turn the boost down, or run C16 and then lean it way out...

If its only a little jerk or misfire that is NOT fuel cut. The way you guys say the symptoms, to me, it does not sound like fuel cut. Jet put it correctly when he said violent. It is very hard on you and slams you forward as if you just rear ended someone for a couple seconds.

slowbubblecar · 10-28-2005

If you have a logger, check what the duty cycle is for the injectors. If you need to borrow one, give me a call between 12:30 and 6:30 tomorrow (Friday). I could try to help you between those times if you wanted to come over. I wouldn't think you would be able to max out the 650s with your setup. What boost are you at and what are your safc settings? My number is 952-412-6087 if you want to call me tomorrow.
James

**JET** · 10-28-2005

Alright, I don't think you or James have experienced fuel cut. It is not a jerk. Like Peter said, it feels like you rear ended someone for about 2 seconds. People have literally smashed their face into the steering wheel. The car is probably just missing because you have a bad tune.

Do you have a logger?

**Shane@DBPerformance** · 10-28-2005

What spark plugs? What are they gapped to? How old are they? Most sputtering is caused by spark plugs, bad plug wires, bad tuning, or boost leaks.

sleepydsm · 10-28-2005

I do have a logger. m100 w/ DSMPocketlogger. Maybe I'm just not using the correct adjectives to describe what happens.

sleepydsm · 10-28-2005

Quote:

Originally Posted by ecoli

What spark plugs? What are they gapped to? How old are they? Most sputtering is caused by spark plugs, bad plug wires, bad tuning, or boost leaks.

It is not a sputtering. It's not a boost leak, it's not bad plug wires. The plugs are newer BPR7ES. I don't remember the gap.

**Shane@DBPerformance** · 10-28-2005

Have you looked at the plugs? A too rich of tune for a short time can make the plugs unusable for boost later on.

sleepydsm · 10-28-2005

Quote:

Originally Posted by ecoli

Have you looked at the plugs? A too rich of tune for a short time can make the plugs unusable for boost later on.

I'm doing that right now. Gawd will I feel like an idiot if the plugs are just shot.

sleepydsm · 10-28-2005

Quote:

Originally Posted by sleepydsm

I'm doing that right now. Gawd will I feel like an idiot if the plugs are just shot.

Plugs are fine. No physical damage, and normal light tan/gray/white color.

sleepydsm · 10-28-2005

Why is it so hard to believe this is fuel cut?