Any help? Lean A/F @ high RPM
#46
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After testing the FPR, went back to inspecting the pumps again and found one of the lines on the pump had come lose from the housing. It is hard to get a screwdriver down in the base of the assembly if using clamps of this nature. Used different barb fittings that were longer in length at the base so you could clamp them down easier to secure them better.
After this we put it on the dyno and the AFR's were in the low 11's again for the pump gas map. Cleaned up that tune and made over 350whp on 20psi which we kept conservative as our goal was the E85 tune.
Drained the tanks and put in 10 gallons of E85. Final numbers were 484whp and 390wtq @ 32.5psi peak. Mid 11's with IDC's at around 88% @ 7400rpm.
The Greddy Profec B Spec II wouldn't give me the boost I wanted, plus when I got anywhere near 100% duty cycle on the unit it would act up. Put a jumper harness together to have the Greddy solenoid controlled by the stock ECU and it worked out great and I was able to get more boost this way and it was much more consistent.
After this we put it on the dyno and the AFR's were in the low 11's again for the pump gas map. Cleaned up that tune and made over 350whp on 20psi which we kept conservative as our goal was the E85 tune.
Drained the tanks and put in 10 gallons of E85. Final numbers were 484whp and 390wtq @ 32.5psi peak. Mid 11's with IDC's at around 88% @ 7400rpm.
The Greddy Profec B Spec II wouldn't give me the boost I wanted, plus when I got anywhere near 100% duty cycle on the unit it would act up. Put a jumper harness together to have the Greddy solenoid controlled by the stock ECU and it worked out great and I was able to get more boost this way and it was much more consistent.
#47
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Your right....sorry about that.
I thought i clicked paged 1 & I scrolled up.....I saw your post on top of page 2, thinking it was page 1....yeah, maybe i ought to try this new thing called READING
sorry bro btw, i havent had / made the time to try your suggestion....thanks
I thought i clicked paged 1 & I scrolled up.....I saw your post on top of page 2, thinking it was page 1....yeah, maybe i ought to try this new thing called READING
sorry bro btw, i havent had / made the time to try your suggestion....thanks
No big deal.
Hope you get the Gauge to EMS issue figured out, let me know if I could be of more assistance when you when you work on it again.
#49
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This car also had an external wastegate dump from the 38mm w/g which didn't trigger anything at all thru the stock ecu as far as knock activity.
#51
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No loss of power or bypassing (well it would have been in this case). The fuel supply line from one of the pumps to the fuel assembly came loose thus not providing fuel to the sending unit and to the rail. Thus the one pump that was working was supplying fuel to the sending unit/rail, but fuel was dumping back in the tank due to the supply line being off. So in turn it would have been bypassing fuel in this case.z
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I had a similar issue when I switched to E85. No matter what I did with the fuel table it would start going way lean past 5500. I found it went away after I more closely adjusted the injector latencies.
Is it possible that because of the dramatic increase of fuel you're supplying with E85 that latencies become more important?
I should mention that I was already running E85 on stock injectors when I switched to FIC 950s, so I was starting from scratch with adjusting my latencies.
Is it possible that because of the dramatic increase of fuel you're supplying with E85 that latencies become more important?
I should mention that I was already running E85 on stock injectors when I switched to FIC 950s, so I was starting from scratch with adjusting my latencies.
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very educational... i just have a single drop in Walbro intank pump and it goes from 11.2 and jumps too 12.1 afrs right exactly at 5500rpm using a wideband on a dyno. I mean immediately jump that high. Richening it up the fuel maps doesnt do anything. Sometimes its sporatic (good clean run in the mid 11 afrs, but majority it does this weird lean hop to 12.1 @ 5500rpm) After reading the above, i'm going to check my fuel pump and make sure its fitting in there tight. But can someone tell me WHY its always 5500rpm like you guys experienced? Does the factory fuel setup demand more fuel right at this rpm range or something?
#54
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Its just how it is I think. Its very close to peak power and the highest boost level before tapering on a stock turbo. On gasoline for instance a stock pump will do the same thing and lean out right there, throw in a 255 and that right where it will then start to go rich.
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John,
is it possible that the Fuel Pressure Solenoid could fail (w/out triggering a code) causing the FPR to not get correct pressure signal from the intake manifold causing a lean condition after 5500rpm? I just thought of this while i was researching the Evo fuel system....
is it possible that the Fuel Pressure Solenoid could fail (w/out triggering a code) causing the FPR to not get correct pressure signal from the intake manifold causing a lean condition after 5500rpm? I just thought of this while i was researching the Evo fuel system....
#56
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I am not sure how that Fuel Pressure Solenoid works to be honest. I know you can take it off and flash away the code and not look back. I havent ever seen one not throw a code though, but I'll admit its always been for idle overrun not low pressure. If you have a pump and still have issues the likely canidate is something in the install F'd up. No O-ring or collar on the pump and its bypassing and losing pressure.
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I am not sure how that Fuel Pressure Solenoid works to be honest. I know you can take it off and flash away the code and not look back. I havent ever seen one not throw a code though, but I'll admit its always been for idle overrun not low pressure. If you have a pump and still have issues the likely canidate is something in the install F'd up. No O-ring or collar on the pump and its bypassing and losing pressure.
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Sep 22, 2003 10:01 AM