sub-zero

Guys I have worked on my car all winter. I have a new street ported motor that was replaced last fall. I decided to go with a Apex RX6 single. I had installed it and just had the Power FC tuned by XS. It is at a RX7 shop up here in Canada that is very reputable for building great motors. The problem is that We can not get it to run under any load.The car runs fine on idel and sounds great. As soon as you start building a little boost it backfires and will not pull at all. I am waiting for the car and have missed my body shop apt. by 1.5 weeks now. The car ran in the fall when I brought it home with the twins but NO PFC yet.

I have the following mods engine mods:
Street port
Apex PFC tuned by XS
Apex RX6
Apex FMIC
Fluidyne rad
Petit air sep
Greddy pully set
1300 cc secondaries
large fuel pump
Dp
MP
HKS carbon Fiber exhaust

They just installed an air fuel meter, EGT,and boost gages.

I am wondering if there is a short in the car from somewhere. I relocated the battery and it wont hold a charge and is brand new. The wiring harness sucks.

What can I do or they do to try to find this problem. I am bummed out after spending so much time and money on the car.Any suggestions would be more then appreciated.

Thanks

Steve

sub-zero

Any one? I need help! The car will not run under boost. It sputters and backfires but the idel is fine. Any suggestions at least?

Thanks

Eric Michel

Steve,

I am suprised no one responed yet, perhaps they were waiting for more info? Anyway here are a couple of thoughts for you.
You might have a problem with your ignition (primary coil?), or more likely you have to much/to little fuel. If you can temporarily install a wideband O2 you would have a much better idea about whats going on. Basically you need to provide some more detailed observations before anyone can really help you here. For example: What is your fuel presure at idle? under boost? How do your plugs look? You said the car idles good but does the car drive normally if you stay out of the boost? You you already know there are wiring problems, I would suggest you fix those first.

Good luck,

Eric

sub-zero

Eric, thanks for the reply. I have "new" everything in the car. It was a piece of **** so i had to repace most everything. I have new Magnicor wires with new plugs. The wiring harness is old and brittle so I could change it but they are expensive so I would like to make sure. The coil paks should be good and worked when I had the twins. Does the igniter ever go bad? or does the map sensor ever go bad? I am at a loss of words. It seems like they dont give a **** and just keep working on other cars. They did my rebuild it the fall and I just looked at the bill and with after market stuff it was over 9000.00 CAN and now they have almost another 2000.00. It just is so shitty that I cant beleive it. I went to the single for easy maintenance and so on. Sorry about the whinning but I am starting to get pissed. If they took out the old and put in the new motor they should be able to figure this out, but here I am trying to get my car home and finished.

They just installed a Haltech air/fuel and the ECU was programmed by XS so it must be close to the right maps.

Could have the screwed up the wiring on the o2 sensor to cause this? The car will not take absolutly NO boost without breaking up, backfiring and so on. The A/F meter goes bonkers. I am new to this although I had a second Gen when I was younger, and could use any help guys. I just want this car to run so I can get it to the body shop for the 2 week late appointment.

Any help by U guys that have went through this **** is again appreciated,

Steve

Eric Michel

Steve,

While I am sure it can happen, I have never seen nor heard of an igniter or Map sensor going bad.
With the Haltech your secondary injectors come online right around 1-2 PSI. It sounds like this part of your fuel curves are not set properly. You really need to get a wide band and someone to help you tune it. There are so many variable from one car to another I am amazed these generic tune curves sometimes work as well as they do. I have shared tune curves with very similiar setup cars before, sometimes they work ok but not always.
I would also recommend monitoring your fuel presure.

Good luck,

Eric