Maft/dsm link fuel cut?

[dunkyfried]

posting for a friend's car:

2g T-28, 680s, dsmlink V2, rnr DP, then 3" back, WB 255, 1g bov

We tried out the 3.0 MAF/MAFT with the stock injectors/pump and with 680cc injectors and the 255lph pump. Did the exact same thing both times. Can he really be hitting fuel cut with 680’s and the 255lph pump? I logged injector duty cycle last night with the stock airbox and he never got above 56%. I’ve never felt fuel cut, so I don’t know what it feels like, unless that really was it. We only tried it in 1st & second gear, but both did exactly the same thing.


It starts to buck & jerk at around 4,000rpm just as the turbo starts to build boost. It’s right before boost starts to build. Definitely feels like hitting a brick wall that makes the whole car shake violently. He’s hit fuel cut before, but said it felt different than this. Only thing I thought of was the fitting where the intake pipe connects to the turbo is a bit loose, but that shouldn’t matter IMO, MAF setup to vent. It’s definitely right around 4,000rpm give or take a few hundred.


when bucking timing going to 6 and both o2 sensors are 1.0 volts. Maft all set to zero and off.


Any ideas what this is ?/?? Did I give enough info for this to be answered?

 

[98spydert]

Fuel cut is based on airflow seen by the MAF, not IDC or IPW. When the ECU sees too much air, it kills the fuel supply giving that "hit a wall feeling" DSMlink has an option to disable fuel cut and boost cut. If you disable it with DSMLink and it's till doing it, you've got other issues.

 

[98spydert]

Check for a massive boost leak if you haven't already.

 

[CanadianTSi]

It starts to buck & jerk at around 4,000rpm just as the turbo starts to build boost.

Definitly have a big boost leak somewhere is the turbo isn't spooling until 4k

 

[dunkyfried]

will try both....thanks for the quick answers

 

[kpt4321]

Diable fuel cut in DSMLink, that ought to answer the question pretty quickly.

 

[Dark_Horse]

Fuel cut is automatically disabled with V2 of DSMlink.