7427 $0D PE disable

[Zefyr]

I am at a loss on this one. I have effectively, as far as I can tell, disabled PE for tuning purposes. However, it still activates and throws off my logs. I remember there being more to disabling PE in $42 when I had this engine running on a 7747 ECM.

[Zefyr]

I know my injector size is off. I am waiting for a fuel pressure gauge to show up in the mail so I can get an accurate fuel pressure measurement. I am using 454 81/lb @ 12 psi injectors in a 454 TB with the 30/lb spring from a 94/95 TBI 454 on a 355. I chose this combo because I would run lean above 4500 rpm with the injector duty cycle nearly maxed when I had the smaller spring and 7747 ECM. I also went back to a Lunati 50161 cam instead of the LT1 cam given the 7427 having a separate idle VE table. Was nearly impossible to get it to idle well with the 7747 since MAP is nowhere near linear with the Lunati cam.

I have maxed out the minimum and maximum temps for PE, maxed out minimum TPS for PE, and still PE activates. Help?

[dispoejoe95]

Eagle Mark posted a thread back in 2013 which I found helpful, maybe it will help you too.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1895-Adjusting-VE-Fueling-tables-with-BLM-data-Tutorial!&highlight=integrator
In it he stated how to disable PE but also added ... "PE - CTS to Enable PE - *DataLog Off 6*" by raising temp to max. This just gives more data to tables before PE in enabled and locks BLM and changes AFR." I'm not sure PE can be shut off entirely but I've searched and this was the best info I've found. I figure if it needed to be or could be shut off, Eagle Mark would have said as much. Someone please chime in if I am incorrect.

Also, you will want to tune the 7427 with a WB02. I've been told this multiple times...mine is on order.

[Zefyr]

Also, you will want to tune the 7427 with a WB02. I've been told this multiple times...mine is on order.

I was planning to do that. Ordered a WBO2 today, and the pin tools.

Thank you for the response. I will read through it.

[Zefyr]

So after installing an LC-2 WB, my BLMs are no longer updating. The INT value changes, but the BLM does not change in closed loop. Not sure what to look at.

[Zefyr]

Found a problem.... Coolant spark was cutting 10+ degrees at normal operating temp. Got the INT and BLMs sqaured away too. The WB02 spreadsheet is awesome. At first I didn't think it worked as it seemed my computer would freeze, just takes a long time to paste the data. After getting my AFRs dialed in across the board, I've added a lot of timing. I'm at 41* for most of my table and negligible knock counts (1-3 counts in <5 cells in ~100 miles of mixed highway and street driving). My question now, is it safe to add 5-10 degrees of base timing on the dist to allow more than 42* without firing the next cylinder? Or would it be better to convert to a DIS or opti-spark LT1 setup? I've been reading about the N* DIS and have mixed feelings on it.

On another note, I am looking at different ECM options right now to run a MPI manifold. Code $59 looks promising, as a friend is already running it on a turbocharged 3.4L with impressive results. My ultimate goal here is to run 5-10 psi, mostly to compensate for the high elevation where I live. I don't like the idea of turbo + wet manifold, but since I am not seeing any more than 18% injector duty cycle at peak RPM, I know I have room to go.

Something interesting to me I found while tuning the fuel trim, peak fuel runs between 4k rpms and 4.5k and tapers off up to 6.5k. The cam I am running claims a useable range of 2k to 6.2k rpms. I am curious if the TB or 4bbl intake might not be flowing efficiently beyond 4.5k.

[Fast355]

Found a problem.... Coolant spark was cutting 10+ degrees at normal operating temp. Got the INT and BLMs sqaured away too. The WB02 spreadsheet is awesome. At first I didn't think it worked as it seemed my computer would freeze, just takes a long time to paste the data. After getting my AFRs dialed in across the board, I've added a lot of timing. I'm at 41* for most of my table and negligible knock counts (1-3 counts in <5 cells in ~100 miles of mixed highway and street driving). My question now, is it safe to add 5-10 degrees of base timing on the dist to allow more than 42* without firing the next cylinder? Or would it be better to convert to a DIS or opti-spark LT1 setup? I've been reading about the N* DIS and have mixed feelings on it.

On another note, I am looking at different ECM options right now to run a MPI manifold. Code $59 looks promising, as a friend is already running it on a turbocharged 3.4L with impressive results. My ultimate goal here is to run 5-10 psi, mostly to compensate for the high elevation where I live. I don't like the idea of turbo + wet manifold, but since I am not seeing any more than 18% injector duty cycle at peak RPM, I know I have room to go.

Something interesting to me I found while tuning the fuel trim, peak fuel runs between 4k rpms and 4.5k and tapers off up to 6.5k. The cam I am running claims a useable range of 2k to 6.2k rpms. I am curious if the TB or 4bbl intake might not be flowing efficiently beyond 4.5k.

Peak VE is not peak Duty Cycle. Your VE table will follow the torque curve. Remember the same VE and Pulsewidth will deliver more fuel as the RPM increases due to more frequemt injector firings.