I had two possibly related undiagnosed problems in the past several days that I'm posting in hopes of someone knowing something about them. Furthermore I'm posting here because I feel DF has the most experience in ECU related areas and I 'm a customer.

Problem 1 (yesterday)

• 2nd gear WOT pull, rpm unknown but surely over 7000, car instantly felt as if I lifted throttle. Was not like hitting wall (what I guess fuel cut is like) or rev limiter but something in between like a fuel supply decrease. Drove to the side, inspected everything, no faults (ses), abnormalities, car runs, sounds, and smells normal.

Problem 2 (started 3 d ago and miraculously vanishes)

• From the first day I installed the FP (1 y ago) I distinctively noticed to modes of operation (confirmed from removing seat and FP assy door and in addition, voltage checks). 1st mode is "low" mode running off ECM supplied 8 vdc, and 2nd is "high" mode from 12.5vdc and is noticed (with seat out) by high pitch scream. The car has allways ran in high flow at WOT and also after eng start for 1 sec (2 min prior to tune).

I'm scratching my head, does anyone know what went on? I dont know if problem 1 and 2 are related but I do know my car isn't possessed - I don't believe in that.


Thanks.

 

Both situations could be related to low fuel levels in the tank. I was running hot laps on the track one day and forgot to fuel up in between sessions and was running out of fuel (situation 1), so the car would completely shut down until the FP picked up some more fuel.


It seems that when my tank is low on fuel the pump operates with much more of a hum (situation 2), but not the all out scream of hi-mode.

 

Drove the car 20 miles today: First 5 miles worked normally (high flow only at wow), then for no reason it started again - goes into high flow with much less demand, like 1/4 WOT.

I'm taking the damb thing out and see if it's clogged and buy a new one if it ain't.

Yesterday's incedent has me worried - hessitated while under 21 psi boost at 7000rpm - lean moment???

1) Can't be boost cut - Flash removed
2) Any malfunction of the MFI and related sys, missfire, or ign would trigger a ses - I had none
3) My gap is at 0.028, if thats extingishing, would I get a ses?

I might move this to to php?f=22 for more views

 

I think something might be slightly out of limits with the fuel press sol or press regulator.

I ran all gas pressure out ( disconnected FP elect connecter and started) and pressure line still had pressure. The filter on the pump however looked good I guess.

On the back of the fuel press sol. is a knob (I think it is), I loostened it 1/8 turn and the fp works normal (hi flow only at wot), welll for now.

 

Did you upgrade the fuel pump?

I have a IX MR and I have the same issue after installing a test pipe and cone filter. If you already have a flash for the mods, I would definetely look to have a 255 walbro. Just my 0.02$!