ecuflasher

iTrader: (1)

Guys,

I have a set of 1000cc injectors and I have already scaled them such that after driving around for a week, the mid trim remained at '-2' and low trim at '-1'. I then tried adjusting the AFR to hit 12.5 for loadcells 90 to 130, 12.0 for loadcells 140 to 200 and 11.5 for loadcells 200 onwards...this is at WOT during 3rd or 4th gear. I managed to roughly hit my target AFR for loadcells under 200 but whenever it crosses 200, the AFR just leans out to 13.xx...this is despite me richening from the stock value of '12' to the max value '7.4'. What could be wrong?

sllt1776

iTrader: (1)

done your fuel pump yet? that was my issue. Of course I have an VIII so my stocker is weaker from the start but i would do that first if I was you. Can't hurt and for $100, cheap insurance plus it is a very easy swap.

ecuflasher

iTrader: (1)

I already have dual walbros....before I took off my standalone and went back to using the stock ECU, I never had this problem. I'm thinking the injector latencies might be wrong but the fuel trims are pretty much spot on. Baffling....

RazorLab

iTrader: (8)

Do you have lean spool on or off?

btw, there are no stock values of "12" in the fuel map 200 load and up, at least on the USDM roms.

Which brand 1000cc injectors?

ecuflasher

iTrader: (1)

I have lean spool off. My mistake...the loadcells at 200 have values of 11.xx instead of 12.xx and by the time it hits loadcell 260, it has dipped into high 9.xx. I'm using the Ralliart fuel map as a starting base.

jmelocik

iTrader: (153)

Are you still running the same latencies that you where running with the stand alone? Which stand alone where you using? I had inadvertently used the AEM latency wizard settings on my stock ECU and was having a hard time tuning. Found out that the AEM uses peak and hold driver and the stock ECU is a saturated injector driver (slower). Anyhow I started adjusting my latencies and was able to get a much better result. Not sure if this would help you at all. but just my .02

Josh

ecuflasher

iTrader: (1)

An update...after trying out different latencies and scaling, I began to think the issue is mechanical. I installed an electronic fuel pressure gauge and sure enough, when the boost comes on, the fuel pressure doesn't rise 1:1 even though I have a rising rate AFPR that is supposed to do that. My base pressure is set at 47PSI and when boost reached 21PSI, the gauge was only showing 59PSI. What's worse, after a few WOT runs, the fuel pressure actually fell instead of rising while boosting. On some runs, it spiked to 59PSI quickly then slowly dropped back to 47PSI before I lifted off throttle. Some runs it rose to 52PSI and dropped lower than 40PSI while I'm still on boost! After idling for 30 seconds or so, the base pressure rose to 47PSI again.

After checking the AFPR for leaks (none found), my suspicion fell on the Walbro pumps. I replaced them with brand new units but the problem remains!

What are the other possible causes? How do you test that a AFPR is in working condition beside checking for leaks? I tried using a handpump to see if it holds pressure and it does but I was told that this is not the correct way to test it.

bondango

What type is it, i know with the Aeromotives you can open and inspect the diaphrams for damage, also, have you checked the vac line to regulator to make sure it isnt leaking or maybe ballooning under pressure

ecuflasher

iTrader: (1)

It is the Aeromotive Pro series and yes, I have checked all the vacuum hoses for leaks..ballooning wise, how do I check with the car stationary?