Wierd tuning issue with Whipple engine - Holley ecu
05-03-2015, 03:39 PM
#12
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Nothing really. It was one of the original units. Lots more bells and whistles on the new stuff. Self tuning and knock sensor were some of the desirable features the customer wanted.
05-03-2015, 03:54 PM
#13
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Current fuel injectors themselves have come along way also compared to years ago, EV 1, Multecs and so on. Not very reliable.
The current ECU's / ECM's are way better than older units. Far more capabilities along with more precisely received inputs and controlled ECM outputs.
The current ECU's / ECM's are way better than older units. Far more capabilities along with more precisely received inputs and controlled ECM outputs.
05-03-2015, 07:52 PM
#14
Current fuel injectors themselves have come along way also compared to years ago, EV 1, Multecs and so on. Not very reliable.
The current ECU's / ECM's are way better than older units. Far more capabilities along with more precisely received inputs and controlled ECM outputs.
The current ECU's / ECM's are way better than older units. Far more capabilities along with more precisely received inputs and controlled ECM outputs.
05-03-2015, 10:20 PM
#17
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This is the Whipple throttle body with 8 injectors mounted in it. The IAT is below the intercooler. FYI, this setup has been running for 10 years trouble free. So I don't suspect a problem with any setup issues. Problem just surfaced after rebuilding the engine with new heads, cam and the Holley ECU. Previously ran a FAST. Still kind of fine tuning with the new ECU and thus ran across this scenario. I guess it's possible the condition always existed but the tune was different on the FAST so it didn't manifest itself. What really triggered the investigation was it would go lean and backfire. What I found out was because it was in closed loop the ECU was seeing the momentary "false" rich condition and removing fuel. When the rich condition clears it would be too lean. Turning off closed loop cleared this issue, so I could then see what was really happening. Hope this makes sense.
S30-
Regulator is boost referenced from the base of the intake and return is to the filter head.
Bob
S30-
Regulator is boost referenced from the base of the intake and return is to the filter head.
Bob
05-04-2015, 10:31 AM
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Cam is 250/258 114 lsa, .680 lift. 555 Cu. In.. Exhaust is Dana with custom tails that exit the corners(Nordic Heat). Water jacketed quite a ways before dumping. Single engine boat and yes gently advancing throttle to get on plane.
05-04-2015, 11:08 AM
#19
What about AE (acceleration enrichment) parameters? Are they triggered differently or at different rates as compared to the old system? I know they are not typically time dependent but might be worth looking into.
Like you I would suspect fuel pooling during extended idle. Will it still stumble with an idle to WOT hammering or just slow roll into the throttle after the 2 minute idle period?
Like you I would suspect fuel pooling during extended idle. Will it still stumble with an idle to WOT hammering or just slow roll into the throttle after the 2 minute idle period?
05-04-2015, 02:39 PM
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Appreciate the replies. I tried slowing AE but didn't make any difference, nor would I really expect it to. You can move the throttle to that point and it's the same even not moving the throttle. Also, keeping in mind the pulse width is not increasing during the rich period so it appears to me the ecu is not commanding more fuel, which you should see if it were an AE condition for whatever reason. No hammering the throttle (1000 HP and Bravo). Moving the throttle quicker doesn't seem to make any difference.
What about AE (acceleration enrichment) parameters? Are they triggered differently or at different rates as compared to the old system? I know they are not typically time dependent but might be worth looking into.
Like you I would suspect fuel pooling during extended idle. Will it still stumble with an idle to WOT hammering or just slow roll into the throttle after the 2 minute idle period?
Like you I would suspect fuel pooling during extended idle. Will it still stumble with an idle to WOT hammering or just slow roll into the throttle after the 2 minute idle period?
