unstable a/f
 

finally got the car put together and had it dyno'd last weekend. still have a couple of issues to sort out, but the a/f kind of has me stumped. no matter how much we played with it, it wouldn't stabilize. couple of guys think it might be a bad FPR or something is up with the pump. to the best of my knowledge the pump and FPR are the original 140k units, I'm going to change the filter also. does anyone have any insight? thanks...

sorry for the crappy cell pic, he was having computer issues.
Attachment 203738

p.s. I should have my wideband today, so I can post logs tomorrow maybe.

Where do you have the MAP vacuum line connected to the MSPNP?

Do you have a filter in the MAP line?
I'm wondering if you are seeing the MAP pressure instability that I have on my car.
When you have the real time tuning window open, do you see the ACCEL / DECELL enrichment lights firing a lot?
Jim

I'm running the vaccum line of the rear nipple on the throttle body, like in the instrustions. we did install a restrictor out of a Evo, but it didn't really make any change.

yes

move the map signal to a tee on the FPR, itll get much more stable of signals.

yes, and put a fuel filter or can on it. My signal is still not perfect, but good enough for god status. You may also need the "capacitor on the power wire" mod that I'm unfamiliar with so don't ask.

I'm not too familiar with the MS, but also make sure to check the wires and position on the air temp sensor, as a bad sensor can throw off your A/F targets.

lets see your enrichment screen too. I wonder if the dyno's WB is correctly hooked-up. You still haven't posted a log. I should also note that if they don't have an innovate WB or Motec WB on the dyno, I don't trust it. I've seen several dynos that are less accurate or generally screwed up...I've still not seen a properly installed LC-1 not read perfectly.

will do :brain:, thanks for the tip.

:noob: what does this mean?

never heard of that before, but I'll do some seraching.

^ I'll check my connects on the IAT, but I think they are good to go. as for the placement, it's the standard Bell spot I guess. a little lower than I would have liked, but I think it's OK.

On my Link setup I have had to re-solder the ground wire on the IAT sensor twice so far and my A/F was all over the place when it happened, so maybe this helps.

can=canister=fuel filter mod

BIG +1

Dealt with this the other night....really easy to not get a good crimp on those, and if yours is in the intake elbow (at manifold) it's subject to a LOT of vibration.

Mine apparently went to some default temp..and would only run IN BOOST.

I have no idea how to post a log... :facepalm:

not really sure what WB he uses, but he has a LC-1 in his E30 and it matches perfectly. we tried several different probes and that one worked the best. I know it runs thru the DD, just not sure on the sensor.

I actually meant to solder the connections on the the IAT, but got in a hurry and was trying to finish up. I'll check all my connects tomorrow, just to double check.

I did get my LC-1 today, so hopefully I can throw it in the car tomorrow and get some new logs.

thanks for all the tips so far guys.

is this useful information?