Rich after Flash

[cc-rider]

I may have something to contribute to this thread. I found that the rich after flash issue I have been experiencing is coming from an anomaly with my fuel pressure & injector pulsewidth. I've finally got a log of this to show (see attached). My fuel pressure decides to add about 10 psi to its normal operating pressure after I flash. However, the injector pulsewidth doesn't compensate for it like it technically should. Its like the ECU is ignoring the fuel pressure increase and continues to use an injector pulsewidth as if the fuel pressure is normal. So same pulsewidth at higher pressure = rich afr after flash. I notice that if I flash the car cold, it doesn't do this. Only if I flash after its hot and at normal operating temps.

Has anyone else seen this happening?

See the attached log. My normal fuel pressure at idle is 50 psi. You can see it is at 60 psi and slowly drops back down to 50 psi over about 15 min. Yet the pulsewidth stays the same.

rich after hot flash - fuel pressure drift.hpl


One last note...this is happening with a speed density tune and MAF turned off. I haven't confirmed if this FP anomaly happens with MAF or Dynamic mode.

[supergt99]

I'm running maf mode and my fuel pressure does the same. I'm using zl1 fuel pump tables. After flashing my fp is just over 60 at idle. After about 8 mins it will return to normal-50psi. Then I can begin logging. This is an annoying problem and I wish someone had a fix for it.

[cc-rider]

Good to get confirmation that someone else has seen this.

I wonder if it's the "hot fuel" tables in the fuel settings. Does anyone know much about these?

[jsllc]

Here is the latest on the support ticket I created "We are currently behind on a number of different projects so it may be a while until we are able to look into this."

GREAT NEWS. There is a fix coming. Took a while to find but there will be a new table.

[GHuggins]

Scott, is this going to be a parameter that will change the countdown timer or kill the reset all together?

[jsllc]

There is a table that adds fuel as the temp of the injectors goes up. If you tell it to not add the fuel then FTrims stay just like they were before you flashed. Injector tip temp goes up but added fuel is zero so no effect. Once tuning is done I am planning on returning the original values.

I tested this on an E38. Engine ECT 171, injector temp 90, FTrims +1 to +3. Flashed it with table of Zeros. Started ECT 175, injectors 175,FTrims +1 to +3. Flashed it with original data back in from first tune ECT 179, injector 179, FTrims -14 to -18. Now pulling fuel. 20% swing. Flashed back with table of Zeros FTrims +1 to +3 now adding fuel.

[Engineer@HPT]

Big thanks to Scott for pointing us in the right direction!

[izazzel]

when will this be available??? and where in the editor will it be?

[jsllc]

There was a table in the ECM that adds based on injector temp. Should be in all of these ECMs in the next weeks. The table is "Offset vs. Inj Temp" under Engine->Fuel->General->Offset. Set that table to 0 during tuning and no rich after flash. There will be a lean after flash. This table must be tuned for your injectors.

[izazzel]

i dont see it looking in a 10 camaro file e 38

[JBZ]

There was a table in the ECM that adds basedon injector temp. Should be in all of these ECMs in the next weeks. The table is "Offset vs. Inj Temp" underEngine->Fuel->General->Offset. Set that table to 0 during tuning andno rich after flash.

That is awesome, great find...and thanks that will definitely help out. Looking forward to that addition.

Any down side to leaving the table zeroed out all the time? Im sure there is i just dont know what they would be.

[jsllc]

i dont see it looking in a 10 camaro file e 38

You will not. It is coming in the next weeks. I tested it on an E38. It will be part of new versions.

[izazzel]

oh thanks for the info i am currently trying fihure out the e 38s on a buddy of mines 10 eitha 454 and figured tah would be on more thing to not have to worry about thank to all for helping to solve this issue it will surely cut tuning time

[jsllc]

FYI until then if injector temp is over 135 fueling is incorrect.

[izazzel]

is there a pid for that havent looked yet between the new ecms time since i have had to do this last and updates to hp tuners seems like starting over with new learning curve

[izazzel]

i found it thanks for the help i will keep a check for the update i know alot of people are looking forward to it awesome job on figuring it out

[jsllc]

There is a PID "Injector Tip Temp"

[openwheel25]

I can't wait. This has been a very big issue. A very big thank you.

[schpenxel]

That is awesome. Great work.

[Niemer]

How did you go about finding that table if it's not showing up in the software?