Weird Backfire/Fuel Cut Issue...

[HartmanMS]

I am having trouble with my talon. I ran a 13.54 the other night at 96 mph(top end is a little lacking due to lack of tuning). On the way home and ever since, sometimes when I floor it, after boost builds and steadies, I hit what seems to be a fuel cut, then it might do it again a few 1000rpm later or it might not. My afpr is set @ 42 psi because any higher and you can feel the loss of top end badly. I am running 18 psi, 91 octane gas, 550cc inj, 255lph pump, new fuel filter, aeromotive afpr, big t28 killer, etc. Could I need a front mount that badly? more octane? could my maf sensor be leaking thru my new homemade intake pipe(I really doubt it, ive tightened and checked thoroughly)? I changed the plugs, and I can't find any problems. I have turned up/down the afpr to see if it changed anything and it did not. The logger results say im rich, but timing is dropping to +6 degrees and then climbing, so if you guys know what it could be...thanks!

 

[92awddsm]

What are you using to control the 550cc injectors? Safc, dsm link, or eprom with compensation? If you have nothing, you are probably so rich that it stumbles and misses in the higher rpm range. If it was fuel cut, you wouldnt even be able to gain a few k rpm afterwards.

 

[HartmanMS]

I have nothing, but the problem is, I also have very little money at the moment, as I am saving up for DSMLink. I would think if that were the problem though, then turning fuel pressure down a few psi would do it, but I don't want to go below 38-39psi with hose off...I went down to probably 40, but I will try doing that again, logging it to make sure its ok. what do you think?

 

[92awddsm]

It will still be very rich even with lower pressure. The injectors stays open alot longer than it needs to be and when you add boost it just raises fp and forces it to be even richer.

 

[HartmanMS]

If instead of buying dsmlink i bought a dsmchips.com chip, would it be tuned pretty well for my setup?

 

[92awddsm]

mine was really close with stock fp. I think I had to richen it with the afc 2% from 4500-7000 rpm on high throttle. Low throttle I had to lean it about 4% across the board. It would definately help a lot even if you couldnt fine tune it. I would suggest trying to find a cheap afc, maybe the old knob style. Then you could save your money for dsm link.

 

[HartmanMS]

well, thanks for the help! I appreciate it.