Hitting fuel cut?

[Junkyardspecial]

Just wanting to know if this is the problem? I went to get my car looked at for a retune, and My af ratios were running pretty rich, he turned boost up maybe 1/2 a psi. Its been a week, I never really went WOT. This morning I did and in third gear the car hit a WALL at 5k. Ive hit fuel cut in other cars but this felt violent, I thought my third gear popped. I did it again later and it did it again, but less violent. So I tried it again while easing on throttle and it didnt hit the "Wall" but it seemed like power faded and that it wasnt as strong in the top end.

Boost before was spike at 20 and hold at 18. It was put up to spike at 21psi, and hold at about 18-19. I since returned the boost back down to normal level. Just wanting to know if my assumptions are correct. Spark plugs are brand new from alst week, wires are less than 10k. Fuel pump is a walpro 255 rewire. I have a buscher racing FPR and Fuel pressure gauge under hood as well, All seems well on that front.

Bumping my own post, adjusting boost seemed to have helped the problem, Still feels slightly flat on the top end but i have no boost leaks, I just think I need a better tune.

 

[TsiJohn333]

what size injectors are you running?

 

[Absit]

Sounds like fuel cut, good job fixing it.
Regarding feeling like you lost some top end, boost leak test and if you have a logger keep an eye on knock/knock retard/timing and IATs.

 

[Absit]

Injector size and duty cycle have nothing to do with fuel cut.

 

[Junkyardspecial]

550cc by the way. I figured it was the small up in boost. The car has a conservative tune to knock, and when im doing a hard pull at about 4k the car feels flat. I am itching to get it re-tuned. This just scared the crap out of me Ive never felt such a harsh fuel cut.

 

[kxfreak125]

My friends 2g hits fuel cut in 3rd all the time, but not in any other gears. Seems strange how your getting fuel cut in 3rd also

 

[Junkyardspecial]

My friends 2g hits fuel cut in 3rd all the time, but not in any other gears. Seems strange how your getting fuel cut in 3rd also

It might be that the gear produces just a tad bit more power over a longer period of time? I mean they use it on dyno pulls and such. Not really sure though.

 

[Absit]

Fuel cut is load based - load over a delay/duration = fuel cut, how often do you ring out 4th and 5th?

 

[kxfreak125]

It might be that the gear produces just a tad bit more power over a longer period of time? I mean they use it on dyno pulls and such. Not really sure though.

I was thinking that also because the only time his car hits fuel cut is 3rd gear about 5k.

 

[Absit]

So your car is seeing more air then fuel so you need to add more fuel so the ecu doesn't throw out fuel cut. step up to a afc or some kind of engine mangement.

That's not how it works at all. Read up on fuel cut.

 

[Junkyardspecial]

I ONLY hit it in 3rd 4th and 5th are fine, I dont get that high in 5th ever anyway. It is tuned with dsmlink and is monitored on SAFC I also have the DSM pocket logger, all variables look great. I just think I need to leave the MBC alone.

 

[Absit]

Slightly unrelated but since you have 'Link and a pocket logger I'd remove the SAFC, take it outside, and set it on fire.

 

[Junkyardspecial]

Slightly unrelated but since you have 'Link and a pocket logger I'd remove the SAFC, take it outside, and set it on fire.

Haha, I Dont have a link which blows, I was going to get one for the tune im getting. It was done before I bought the car, I Was a little confused myself. Ill be sure to throw it in the microwave when I get the real deal.

 

[Absit]

If your car was "tuned with 'Link" then you have 'Link. It's part of the ECU, they don't remove it when they're done. Pull your ECU and look around, you may only need a cable and software.

 

[Junkyardspecial]

Alright that was the only thing I was confused with when I purchased this car was the tuning. It has a SAFC in dash at all times, but the previous owner said tuned with DSMLink and had a receipt with tune. Is the ECU under the kick panel or behind the radio?

 

[Junkyardspecial]

That kind of weird why would there be a SAFC when its tuned on dsmlink? I thought dsmlink takes care of fuel and all that good stuff. Yes the ecu is behind the radio.

Im new to DSM's so Im not really sure. How would I get to it, just pull radio out?

 

[Absit]

Im new to DSM's so Im not really sure. How would I get to it, just pull radio out?

Hm, I don't know on a 1G, never had to do it. I'd start searching, it's bound to be around here somewhere.

 

[kornfedgsx]

The panels on both sides by the passangers feet and drivers feet under the radio take those panels off and you can get to it like that. I think the guy was yanking on your chain. i think it only got SAFC if it all mounted then thats it slim chance you got dsmlink but who knows.

 

[spadepro22]

Boost leak maybe. Does it backfire?

http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/186971-what-fuel-cut.html

 

[Junkyardspecial]

Thanks for the info to get to the ecu, Ill check it out later in the week. I was going to buy the DSMLink anyway, so Ill just get rid of the SAFC soon. The car has never backfired on me. And I did a boost leak test and Im golden.