I'm in the process of tuning my fuel map and occasionally hit cells that are so rich the car stumbles (afrs register around 9). I've heard mixed opinions on whether this can damage the motor. Obviously, it can foul the plugs, but I'm not too concerned about that. I would appreciate any input.

Best Regards,

Chris C.

 

The answer is no, Chris.

B

 

how long are these stumbles? The only problem that i could foresee with this, is the possibilty of contaminated the OIl with gas. But that usually involves running rich for a while.

 

~1-2 sec at a time.

Can you elaborate on this?

Thanks for the replies guys.

 

I think what he's saying is that if you have enough unburned fuel in the chambers, it can wash the oil off your seals and kinda drip into the oil pan. Then you have contaminated oil.

 

running too rich, will dilute your oil with gas. common with 3rd gens. turbojeff posted a while ago about some oil samples he had done. They all came back with 10% diluted with gas.

 

I have this gassy oil problem. That is why I change my oil every 2K or less. I always thought it was my side seals but am hoping you guys are right about running rich being the cause. I have been rich for a while (in fuel in my engine only unfortunately) and finally have had the chance to start tuning again. I hope it will clear up.


I am guessing you have cleared up the primarries issue Chris? I have been doing alot of tuning lately and have made some changes to my timing also. I will send you the finished map in a couple of weeks.

 

Hey Shawn,

I finally got the car to start with the 83lb/hr primaries by switching from 10 to 5 ohm resistors. When I first got it running it would lean out when I reved it over 3k in vacuum.
I gradually added about 15% more fuel to the vacuum cells and that solved the problem. Believing there was a pattern I added 15% to all the pressure cells above 3k as well. Unfortunately, in light of all the 9s I've been seeing under boost, I think my assumption was incorrect.

Right now I'm up to about 5-6psi. I'm going to spend a little more time tuning at this pressure level by trial and error and then I'm going to use the results to modify my starting point for the higher pressure rows.

 

Are you using a wideband/datalogit combo?

Did you change the ratio's for your injectors? Mine would momentarily go lean until I changed the ratio?

Chris

 

Hi Chris,

I'm using a Tech Edge Wb02 (LSU4) with the datalogit. I get the same readings using the TE and FC-edit software. I changed my setting 5 values to compensate for the larger injectors. Three seperate tuners have verified that I have the correct Tab5 settings.