1G Question about fuel cut

[Big Phatso]

First please don't shoot the newb, I'm new to DSM.

Ok so I am looking at purchasing a 92 TSi AWD. I talked to the guy and he said at around 4k RPM it cuts fuel. He said he is running a 16g turbo and a MAF translator with GM mass air flow. As far as I can gather the fuel injectors are stock.

Besides the solution to the problem, I have to either trailer the car 3 1/2 hours or ask you guys if it is "safe" to drive the car as is for 3 1/2 hours. He said I can swap the stock turbo back in or buy bigger injectors. But neither of them will help me get the car home.

Should I just trailer it, or is it safe to drive it as long as I keep the RPMs low till I can get it home and swap the stock turbo back in till I can get the right size injectors (which would be what size)?

 

[Coreyred95]

i probably would drive it is i was certain that that is the problem.

 

[Big Phatso]

Ok cause he said he wouldn't drive it because it hits 4k REALLY easy. I don't want to miss this deal as I have always wanted a TSi AWD I just don't have a means to trailer the car. How could I test it to see if that is indeed the problem? Or is it complicated?

 

[car46999]

If you are concerned about driving it, why not rent a trailer and truck from Uhaul? It should be around $100 for a local rental of a truck and trailer.

 

[Coreyred95]

my TSi AWD runs around 3300 RPM running at 75mph down interstate, so you should be good. you shouldn't have any problem keeping your RPM below 3k.

 

[TSiAWD666]

The car won't fuel cut by just getting to 4000 rpm. It needs to be seeing more air than the ECU is configured to handle and THEN it will cut. If you just baby the car then you won't have any problems keeping the air intake low. Just don't floor it and you'll be fine.

I'd be a bit suspect though of this arbitrary 4000rpm number he threw out there. I'm wondering if he actually has a different problem and the ignition is breaking up at around 4k rpm no matter what airflow the engine is seeing. You should verify this.

 

[Big Phatso]

If you are concerned about driving it, why not rent a trailer and truck from Uhaul? It should be around $100 for a local rental of a truck and trailer.

Because 7 hours round trip would probably cost me a little more than $100. I haven't called yet, I wanted to see if I could drive it first.

Thank you all for your input.

 

[LKWTSI]

Because 7 hours round trip would probably cost me a little more than $100. I haven't called yet, I wanted to see if I could drive it first.

Thank you all for your input.

Just as a rough idea, here's a truck + trailer rental for the day PLUS insurance.

UNDER $100. of course you could do cheaper if you have a friend with atruck and pay his gas.

Check out the quote. Session timed out

Of course based on the above posts, I have to agree that unless you test drive the car and find out that the cars hitting a wall at 4K and not just under WOT conditions I'd be inclined to drive it. Normal driving conditions shouldn't cause fuel cut even with this set up.

 

[Big Phatso]

Just as a rough idea, here's a truck + trailer rental for the day PLUS insurance.

UNDER $100. of course you could do cheaper if you have a friend with atruck and pay his gas.

Check out the quote. Session timed out

Of course based on the above posts, I have to agree that unless you test drive the car and find out that the cars hitting a wall at 4K and not just under WOT conditions I'd be inclined to drive it. Normal driving conditions shouldn't cause fuel cut even with this set up.

Well I just asked him and he said when it gets to 4k or so it feels like the car was rear ended. So should I look into the trailer?

 

[nek]

Ok, this is the same thing that happends to my car and I use it as a dd. Its fine to drive, as you said its hitting fuel cut caused by the 16g boost creeping past 15 psi. This is why he says you can either put the stock turbo on or a upgrade the injectors. Ive hit fuel cut a few times and it doesnt do any extreme damage to the engine. I would never consider towing the car and I would definitely drive it. I never even go above 3500 crusing with od on anyways. This is my two cents.
As for what injectors, basically anything bigger then stock (450) .... 550s work 650s etc.
Dont forget to upgrade that pump to a walbro 190 or 255... <-Research which is right for you.

 

[LKWTSI]

Well I just asked him and he said when it gets to 4k or so it feels like the car was rear ended. So should I look into the trailer?

Like it's been said in the other posts, fuel cut is the ECU pulling the fuel when in reaction to it sensing way too much air v's fuel. I've never personally experienced fuel cut, but everything I've been told and read about it, it's very aggressive and distinct. At what RPM conditions, when it happens would be something I'd have to do some research on, but I kind of get the impression it's up in the higher RPM range. But I guess with a GM MAF, it's possible to get it at lower RPMs.

I'd ask the seller if the "so called" fuel cut happens at 4k in every gear or just in one particular gear and go from there. There's a lot of different reasons it might be stumbling at 4K and without driving it and getting a solid feel for what it's doing it's going to be hard to advise you whether or not to spend the money taking a trailer up to get it unless you are set on buying it and bringing it home. Other wise I think you'd be perfectly safe driving it home, JUST don't romp on the gas and get the "4K wall", if you know what I mean.

 

[onlyhonestone]

also don't put the stock turbo back on , just upgrade the injectors, i have the same problem, but i had 2 parts of my maf honeycomb removed, it lets me hit 17psi safely without fuel cut, anything more and fuel cut happens, which is good because my engine won't detonate and destroy itself.

 

[turbo laser]

^^^agree with above. I have a bone stock 1g with a 16g. I was having problems with fuel cut, and it ended up being my ecu. I tried a friends and i boosted without hitting fuel cut, so that was all i needed to do. Otherwise, the 450cc injectors should be fine for a handful more than wastegate.

 

[Big Phatso]

I wub you guys. Of all car forums I have ever been on everyone here so far seems to be pretty cool. Thank you all for the help and advice. I am trying to go see and hopefully buy the car tomorrow. If I do, LOTS of pics will follow. Again, thank you all.

 

[turbo laser]

yeah post pictures, and let us know what the problem was. and if it was solved beforehand or if you are gonna have to do it.