MicroSquirt.com read only forum (Jan.15,2018)

Ok took the car to the dyno today. The sensors start acting up (fluctuating) up top. We thought it was the map accel flipping on and off from map fluctuations, but that wasn't the case. I tryed changing time, spark duration, dwell duration....



pretty much all the runs were choppy like that ecept for one of them witch was ok. Is it possible that iterferance with the timing could cause this?

Can you post your datalog of the run?

ehh...Don't think so.

I think I figured it out though. The MS guru at XAT said he went back over the datalog AFTER we turned the accel enr all the way to TPS based (previosly 50/50). It didnot help, but he noticed that the tps was fuctuation and dipping more fuel into the mix. I also fond that I have the BAT/CLT/ect lag fator set to 100, I turned it down to 30 and it smoothed out alot of the flucuations. I also turn down my PW compenstion setting in the injector control window (pw/v) .It was set at the stock .2ms/v. I turned it to .05ms/v. I igured that the 96lb/per injectors, that the .2ms/v was a bit much coupled with the battery siganl jumping from 13.1-14.1 and every number inbetween....the o2 correction was fitting but couldn't stay on top. I noticed a lean stumble every now and then while cruising, an once and awhile under boost...but that is gone now.

As for the dipping at 6800-7200, I think I need less plug gap. I did a pull at 10psi tonight after work, and it felt better, but I didn't get a chance at 18psi due to traffic. I need to do a pull in 3rd, or else I won't ahve traction, and 3rd goes to like 105mph...so Ineed a bit of room to get up to speed and slow. I would rather just be stupid and wait for an open road then to do something extra stupid in traffic.

Dyno help

Ehh... don't think so.

huh?
anyway,
right when I heard your symptoms I thought that it could be voltage related. That sounded alot like what my car did when my battery was failing and the voltage wasn't constant. Are your grounds flaky or something? Why is it jumping around that much?
-teb

Yeah...I didn't have the best ground. I had it grounded to frame that surrounds the radio/ac controls. I also had other things grounding there. So i bought some shielded fat speaker wire and ran it back to the battery. I will ground the pcm and the ic module to that same wire when I get a chance.

I also found a bunch of poor connects under the dash....what freaking idot did that kinda of electrical work?

<-----hint


I still feel it loosing alot of power in the 68-72 range. I think think I have a weak spark thing going on.

I need to edit my .ini file so I can up the dwell saturation time. I turned the spark duration down from 5 ms to 1.5ms. I didn't notice anything different in boost, but it burns right threw a lean cruise condition. It used to stumble when it went 15-16:1, so I had it running a little rich so it wouldn't buck when it went lean, but it runs threw smooth now...plus it helped alot wen I turned down the ms/v inector compensation values. .2ms on the 1000cc injecots is ALOT more fuel then on a 42, so it makes sense to turn it down.

I went today to get a set of MSD coils to see if it helps on the high end, but the race shop only had one coil :"huh":

So it looks like I will install ONE tomorrow and just crank it and see if there is any noticeable difference like when you install a DIS-2. If there is any difference, I don't think it will be as noticeable as the dis-2 though...but we'll see.

i noticed a difference in idle when i went to the MSD coils. you can tell they have a better spark then stock. And a difference when I went to new wires too. Old wires suck, and they seem to burn out faster on turbo cars as well. Maybe the extra heat or something? I don't know.