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-   -   E85 and ID2000s (https://www.rx7club.com/alternative-fuels-249/e85-id2000s-1031662/)

13brenova 04-06-13 09:13 PM

E85 and ID2000s
 
I'm running into an issue and was wondering if anyone could shed some light. I just switched from running C16 with 4x1680 injectors to E85 with 4xID2000 injectors. The issue is that the fuel map in my PS1000 required an INSANE amount of additional pulse width to get the car to start, idle, and hit the target AFR. I would expect to see......

Switch from C16 to E85: +30%
Switch from 1680cc injectors to 2200cc: -24%
Final global adjustment to fuel map: +6%

What I am actually seeing.....
C16 tune w/4x1680s: 1.114 ms @ 3000 rpm @ -6.6 in/Hg = 13.5 AFR
E85 tune w/4x2200s: 1.922 ms @ 3000 rpm @ -6.6 in/Hg = 13.5 AFR

Another.......
C16 tune w/4x1680s: 4.002 ms @ 4000 rpm @ 5.1 psi = 12.5 AFR
E85 tune w/4x2200s: 6.930 ms @ 4000 rpm @ 5.1 psi = 12.1 AFR

That's a 72% increase vs the expected 6%!

I've gotta be missing something. At this rate, I can't even boost 12 psi without running out of injector!

Things I've checked:
- Fuel pressure is good at 43.5 psi
- Voltage is good at 14.5
- The ECU has been updated with the injector dead times as published by ID
- Injector resistance has been set to "high" in the ECU
- EGTs are even on both rotors
- Injectors have "ID2000" printed on them

It almost seems like the injectors are acting like they are somewhere around 1300cc? I can even get the car to idle at 1200 RPM, when with the old 1680s, the lowest I could get was 1600 RPM.

Very odd. Any suggestions?

13brenova 04-07-13 09:11 AM

I want to clarify something. I am running VP's C85.....not E85. Was doing some research last night and it looks like the ID2000s don't play nice with MTBE, which it looks like is in C85. Apparently it swells an internal seal in the injector, which results in reduced flow.....somewhere around 1300cc, which is pretty close to what mine are acting like. It just seems kind of odd that this happened so incredibly quickly. The injectors were acting like this immediately on startup. I put the C85 in the tank, primed the system to check for leaks, and cranked it over. Not 100% sure this is the issue, but it's something to think about.

FullFunctionEng 04-07-13 12:08 PM

Sounds like this is the issue. They will return to normal flow once the mtbe gets a chance to evaporate out of the injector.


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