Baker

Hi Guys

Need a little help if possible.

The car went into limp mode this week after giving it some spirited driving, my initial thoughts were the dreaded maf sensor has gone again!

Got home and read the fault code which did indicate it was the maf. Before the maf died on me, when driving hard in 4th gear on full boost I would get fuel cut after it had been on boost for 5 seconds or so up at about 5000rpm.

I had experienced this problem a few times in the months previous to the maf failing, but in fairness I don't often drive the car under full load in 4th due to the speeds you would reach and usually having my kids in the car with me!

Im going to change the maf and do an ECU reset etc, but do you think I was hitting the fuel cut due to the maf being on the way out?

Car is remapped and had the maf changed about 18 months or so ago, by looking at the boost gauge prior to the maf going it didn't look like I was over boosting either and when ive experienced fuel cut ive had plenty of fuel in the tank

Anyone have any ideas or does it sound like my fuel cut problem was due to a dodgy maf on its way out?

GlesgaKiss

Hi, I think it could just be coincidental that your MAF has gone now. I had fuel cut for about 5 months in 4th and 5th on full boost, and then last week the MAF went. Replaced that, but it was still getting fuel cut, as I expected.

My car was running a full decat stainless exhaust and induction kit without any kind of remap, so that was my problem. The boost was just creeping up slightly into the standard ecu's fuel cut zone.

A specialist also diagnosed my car as having a fault with the ecu, so I booked it in with Andy Forrest to have an Apexi ecu fitted and mapped. That was done today and the fuel cut is gone - as the car is now mapped perfectly for the mods done to it, and boost is controlled better.

When you say your car is remapped, has it's original ecu just been mapped? Or does it have a stand alone? Have you added any more modifications since it was mapped?

If you havn't, I would suggest taking it to a specialist. Mine didn't even charge me for having a look at it when it was getting fuel cut.


Alan

Baker

Thanks for the quick reply, keep them coming!

The car is modified a fair bit:

VF35 Turbo
STI 8 Top Mount Intercooler
Uprated injectors and Walbro fuel pump

Its been remapped using the existing ECU but with ECUTEK software if that makes sense. Ive had it remapped twice and never had any problems ,the last remap session was about 6 months ago or so and the car has always been spot on. No further mods have been done since its been remapped.

Im hoping that the fuel cut problem was just the maf but I might not be so lucky. In 1st, 2nd, 3rd the car boosts to 20psi, in 4th it boosts to 22psi but I think its always done this hence why I dont think it is over boosting but I could be wrong?

Think Ill have to bite the bullet with a specialist but moneys tight at the moment so like most im trying to get an understanding of what wrong before handing the car over.

Graz

The failed MAF is unlikely to cause fuel cut.

Also the fact that you get more boost in the higher gears is fairly normal, the engine is under it's highest load so will spin the turbo faster. It's in this zone however that you may be getting some boost creep causing it to hit the fuel cut limit. This would have been raised from the factory setting by your mapper, maybe they were being a bit too cautious, or perhaps it is over boosting.

I have heard that some of the VF series are prone to boost creep and that having the wastegate ported can be enough to allow it to bypass more exhaust gasses. What downpipe are you running? The open neck variety are generally considered the best for wastegate flow.

Baker

Not sure on what down pipe I have.

I took a trip down to the my local specialist today who said best thing to do is to bring it in so they can properley diagnose it as they said it could be a number of different things causing the fuel cut.

Fingers crossed it will be a simple cheap problem to fix!

Luminous

iTrader: (3)

I had some fuel cut issues recently that were cured with a replacement MAF sensor. I was getting fuel cut in either 2nd or 3rd, generally just after the car had been warmed up. I'm no expert on these things, I just know I cannot afford a remap at the moment, as much as I would like to have one.

Baker

Had the MAF replaced and car is ok now, but still got the same issue with the fuel cut.

Had a quick look over at the boost gauge and I believe it was reading 25 psi when I hit the fuel cut.

Its these little problems where I dont actually know what is wrong that gets to me, spoils the fun of driving the car.