Yesterday I removed DSMLink from my '05 Evo, re-installed the stock ECU and started using ECUFlash / EvoScan to tune. The main reason is because I cannot pass the OBDII test for inspection with a '95 DSMLinked DSM ECU running an Evo.

Other than the ECU swap, the car's configuration has not changed. I've got the fuel trims under control, but there's a couple behaviors I'm seeing with the tune in the stock setup that I didn't with DSMLink.

Here's the mods I have:
K&N filter & Dejon hard pipe (MAF to turbo)
FP2 cams
FIC 850 injectors (they flow test at 890)
High-flow cat & 3" cat-back
Everything else related to power generation is stock

The issue that has me (and others) stumped is when the car is moving, the throttle has no effect up to ~20% TPS (EvoScan). When the TPS crosses 20%, the car lurches back to life and all is normal. It happens at all speeds, in all gears. However, with the car stationary the slightest touch of the throttle causes IPW & RPM changes as expected.

This did not happen under DSMLink.

Here's a snapshot of what's going on. 2'nd gear in the parking lot. Look at the circled areas. TPS goes from 13.3% (minimum logged) to 20% and IPW/RPM does not change. Once the threshold is crossed, the engine springs back to life (and the car bucks pretty badly).



I searched here and elsewhere but was unsucessful in finding someone with a similar problem.

Any suggestions?

 

did you rescale the for larger injectors?

 

yes

 

The flash I was running had many modifications from stock. To eliminate them all, I took the stock flash, upped the injectors to 770 and flashed it. I still have this problem.

I'm open to suggestions.

 

what about injector letency voltage. that plays a huge role.

 

A huge role in balancing LTFT, but it has no effect on this problem.

 

Been thinking about this since you posted, I would think about the accel enrichment settings, see if they are corrupted. The odd thing is that there is a partial response as soon as you move TPS?

 

All ROM images I have have the same accel enrichment table data as the stock image:
1.62
1.50
1.12
1.00
1.00
1.20
1.33
1.43
...
1.43

 

it sounds like you're going into a load column that doesn't have enough fuel so the car stalls out, but the way it comes back to life suggests it's a dead spot in the tps sensor. So you can slowly move the TPS through the range while you're parked and it looks fine in the logs?

I'd like to see the logs from the above screenshot. Airflow, TPS, RPM, IDC, 02, timing and the fuel/timing map would be helpful.

 

Does the ECU throw a CEL if it isn't connected to the speed sensor?

 

The IPW does respond when you increase the TPS, but not in a linear fashion, any chance you can post your ROM?

MB

 

Sorry for the delay - hectic week.

I took another log to better demonstrate / isolate the problem:
1) With the car stationary, slowly increase throttle to > 20%
2) with the car in second & moving, release throttle, then slowly increase throttle to >20%

Car Stationary:
Notice that there is an immediate RPM increase with increased TPS value, even under TPS=20%


Car moving:
Coasting in 2'nd and applying slowly increasing throttle pressure had no effect (RPMS and MPH decrease as if TPS reads 0) until after ~22% TPS when IPW goes to expected and the car lurches forward:


Here's the log

I'm still stumped.

 

clearly when the car is under load and the TPS increased the IPW does not and thus RPM and Speed fall off.

I couldn't find these events in the logs you attached, maybe it's there and I missed it. Please start you log just before you recreate the issue and shut if off right after you've done it to help me see it in the logs. Also add 02sensor to the log so we can see what the air/fuel looks like.

can you pull the fuel and timing maps from the ECU and post those? if they belong to a vendor don't do it.

 

The graphs are from the same log I posted - look at the corresponding times.

The maps are from a vendor - I cannot post them without their permission.

 

sounds like you need to talk to your tuner then