Having what feels like fuel cut at ~6500 rpm in 3rd gear. From searching the forum it seems like this is not a rare problem but there also is not a straightforward fix. The car really lurches at about 6500 rpm and if I keep on it, it will start accelerating after the lurch to go up to redline. I am getting a boost guage ASAP but I was told by PFS the primary is boosting 10 psi and the secondary is boosting 11 psi, only mod is a downpipe. Even though nearly stock, could I be overboosting to cause fuel cut? PFS recommded I get the ECU piggyback but that seems overkill for nearly stock car - their other solution was to drill boost pill but I really don't want to do that as it will cut down boost across the board. I am going to check fuel pressure friday afternoon, but I don't think this is the problem since car runs fine all other times. Any ideas?

 

It doesn't sounds like fuel cut, but it's hard to say without actually being there to experience it.

Fuel usually fells like you just blew the engine. The car pretty much loses all power at that point and takes a little bit to recover.

 

ive had a fuel cut, and basically my car went kaput

i was about to order a new engine when i was told it was really the fuel pump =p

 

If the "fuel cut" was initiated by the ECU, I'm not sure a new or aftermarket fuel pump would solve anything. You probably need to lower/control your Boost via a boost controller, or get a PFC to make the proper , safe adjustments.

 

Get a boost gauge asap. You need to know if your overboosting. If so, install a boost controller. Lay off WOT till you get the Gauge installed, otherwise you may have to install an Engine.

 

The FD ECU attributes "overboost" to anytime the inj. duty cycle is over 65%. It has almost nothing to do with boost. This is why you can spike to 15 psi without few cut in certain situations. It is also why you can fuel cut at stock boost if you have done a few mods and have a strong motor.

My FD was runing 10-8-10, and it would cut and recover, roughly at ~6000, ~7000, and ~7800, but I don't remember excately because that was years ago.

2 ways to fix the problem (like PFS said)

#1 (cheap) Turn down the boost with needle valves or pills.

#2 (expensive) Get some sort of fuel management

 

That is completely false.

The stock ecu uses base fuel maps with only corrections for temperature. What you are suggesting isn't possible given the way the stock ecu works. Whoever told you that was full of ****.

The stock ecu fuel cuts at overboost, not duty cycle.

 

http://www.scuderiaciriani.com/rx7/fuel_cut_info.html

 

Thanks Mahjik, that's a good site and I read the boost pattern earlier which made me think... (is this totally wrong?) average of 11 psi (secondary) and 10 psi (primary) = 10.5 psi when both are boosting fullest, so if that somehow crept to over 10.7 with both boosting, would that cause the ECU to temporarily cutoff power until excess air went out wastegate and then power is regained?? And...I am trying to get a boost gauge but I can't seem to find a place in Wash, DC metro area that carries the DEFI D-gauge. Don't feel like paying/waiting for shipping on Internet buy but will if I have to. Anyone know a place?

 

I think you're going to have to order it regardless. However, SPI Powerexcel is a large US distributor for Defi and is right in your backyard.