Finally, my Rb is running pretty good, but...

[lmnhed]

Well I finally got my 89' RB20 hatch running tonight with the new turbo (rebuilt 86' Z31 Turbo). It feels good. It is pretty laggy but I still need to set the timing. It lights up over 4k though, and sounds awesomely nasty with the open O2 pipe. Right now it is hitting 10-11 lbs, it feels awesome up top but I should turn it down a little till I work out all of the bugs. So now to the problem:

After it warmed up it started to cut fuel at some higher rpm points. After I had driven it around for a while it was consistantly cutting fuel around 5k when at WOT.

So my question is "What do you guys think the problem is?"

Could it be timing? if it is I'll know tomorrow when I double check the previous owners timing.All I can think is its MAFS related. Maybe the MAFS is maxing out.I know I am not boosting more than 11 lbs, if that helps

Let me know what you guys think, TIA.

[krayton]

im thinking maf is maxed out? any way to turn the boost down?

when i ran the stock rb25 id get a fuel cut at 3200 rpm when running 17lbs because of the maf being maxed

ill be doing the t3/t4 upgrade when i get back, so your rb20 turbo will be ready if u still wanna use that.

[lmnhed]

I can turn the boost down if I need to becuase I have an adjustable HKS wastegate actuator on the turbo. And thanx for the offer but this turbo is good now, so i shouldn't need the RB turbo from you.

[lyon23]

I think your maf is maxing out, since that turbo is bigger its reading and sending more air...same thing happens t me at 5k...now my question is, is the maf maxing out or the car running lean? because I have a q45 maf on and I can run up to 18psi on the stock turbo and not max out untill it gets to 5k...in cold nights I run it at 15psi and it maxes out again at 5k but i understand that colder outside denser air...as soon as I get the bigger turbo I'll put on the 450cc injectors i got and get it tuned..

oh yeah q45 connected with safc2 to change signals...

[lmnhed]

OK, I put new plugs in I thought it fixed it. But it ends up it only does this fuel cut type thing when it is warmed up and been running for a while. I am gonna check Fuel presuure today to make sure that isn't a problem. What pressure should it be at? The car has an adjustable FPR on it. I also may swap my sisters Z32 MAFS on, since her car isn't running and I have an Safc-2 that I can put in the car to run it. What else should I check? I am planning on running this car at a track event this weekend, so I really need to get it running properly. If you guys have any suggestions I would greatly appreciate it. TIA