Hey Guys,

I just picked my car from C2 after having them install a ported motor, PFC & 1300cc injs. Now, my car is BACKFIRING when ever the air pump comes on. between 1000 & 2000 rpm. Basically, when ever I let off the gas I hear a succession of loud rapid pops.

Will installed the PFC and added 10% more fuel across the board to compensat for the ported motor and the 1300cc injs.

Help, the backfiring is excessive and embarrasing...Does anyone have and ideas on how to fix this? I have the Commander & Datalogit. And I do plan to get the car dyno tuned after the motor is properly broken in.

Also, the car is running really hot 110-114C...I have evans coolant also.

 

Just got off the phone will Joel at Pineapple and he said that timing could be the issue... and causing the motor to run hotter.

 

Less airflow (well velocity) at lower revs thanks to the port job, less fuel needed. You could be rich in that region as well. I've been experiencing this and tuning it out slowly. Make sure they put the correct injector settings as well. I need quite a bit less fuel in the vacuum region than I did previously. Timing and split could also be an issue.

 

My car w/ similar setup does the same. I've noticed its much more pronounced adter AIT temps get over about 45 C or so...

 

The injector settings are at 1300 cc. I'm pretty sure that I am running very rich.

Does anyone out there with similar mods want to help me out by emailing me Datalogit .dat file?

Mods:
Streetport
1300cc Secondaries
CAI
Large SMIC
DP
HF Cat
HKS Twin Power Ign. Amp
Cat-Back

I know that this isn't the safest way, but at least I could drive the car ans take it easy until I can get it dyno tuned...here's my email address: jpandes@hotmail.com

 

Check out this link, there should be a map there you can use for now until you can get it dyno tuned.

http://rx7.homeip.net/pfc/

Matt

 

Okay, I'm stupid. I'm trying to enter in these fuel maps into my Datalogit. When I try to enter the 121 in the cell that currently says .500, the value ends up 1.496. Am I missing something? Is there somesort of setting on FC-Edit that converts these values?

 

Have your car dyno tuned.

OSdesigns is in the bay area. www.osdesigns.com pm him and he can make your car run much smoother.

 

check the settings dealing with pim scale offset with the PFC. I was going to get mine to zero out when the car was off, but key was on. Check the area on settings on page 3. Unless you have a 3 bar map sensor or some other unit, it should be on setting one with a value of 35086 and somewhere aroun 3947 for the offset. the offset is the value I was going to lower and by dropping it 30 points, it made my car pop like that when I let off the clutch.

Tim

 

Update: I solved the heavy backfiring with help from another forum member(Don't know if he wants to be named here)by uploading his PFC settings using the datalogit. We have similar mods and his maps/settings should be good for my car until I get it dyno'd tuned

Thanks.

BTW, this datalogit is really easy to use!

 

I have some .dat files too, if your interested

 

ugh, i have kinda the same issue but no datalogit.

 

Glad they worked for you. Anyone that wants to have an FD tuned I recommend Rick at Rx7fashion. he knows what he's doing, thats for sure. Our mods are similar, I have a midpipe so the difference is going to be top end, you will be a bit rich. Here are my results from 5K on in WOT:

5000 11.94
5500 11.70

6000 11.70
6500 11.53
7000 10.88
7500 10.85
8000 11.54

from 7-8000 you are gonna be pig rich with the highflow cat . Also, I have 3MM seals, if that makes a difference.

Let me know if you need anything else .

 

That's ok, I'd rather have the extra margin for error. Better safe than sorry

THANKS DAVID !!