EVO IX fueling troubles...
I think the first order of business would be to get a fuel pressure transducer on there and log boost vs fuel pressure.
I did this on my stealth and found that my fuel pressure wasn't keeping up with my boost as it should be 1:1. I installed a kenne bell boost a pump and added a little more voltage to my fuel pump and now it's 1:1 up to 35psi.
the underlying problem for me is a single walbro but they don't mind extra voltage and I prefer one pump over two.
I did this on my stealth and found that my fuel pressure wasn't keeping up with my boost as it should be 1:1. I installed a kenne bell boost a pump and added a little more voltage to my fuel pump and now it's 1:1 up to 35psi.
the underlying problem for me is a single walbro but they don't mind extra voltage and I prefer one pump over two.
Last edited by saiyanzzrage; Nov 18, 2007 at 05:43 AM.
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if that's accurate then it stands to reason that you don't have a problem...now you need to figure out who has the busted wb02 sensor, the dyno or you 
did you both log wb02 at the same time while on the dyno yet?
did you both log wb02 at the same time while on the dyno yet?
The pain in the **** about this is that I live 3 and a half hours away lol
I will be back in CBRD's area next month, so maybe we will figure it out then
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if you have a big cammed car that might be somewhat normal until it's dialed in. They are much more difficult to get to a fixed 14.7 AFR at idle, especially if the AC compressor it kicking off and on or the fans are kicking off and on, these situations change the load on the engine and sometimes it takes the ECU a minute to adjust the 02feedback trim and catch up...by the time it does the fans/AC is doing something else and you get into that nasty loop. Sometimes all you can do is get the fuel set between the two situations so it doesn't have to trim as much in either direction.
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well, again.. ill state this.....
We were using the wideband in the car AND on our dyno...
I had tuned two cars earlier in the day, and it read spot on..
the AEM UEGO in the car was reading the SAME as the Innovate on our dyno (about .1 of afr off).....
we looked for exhaust leaks and could not see or hear any... all of the vacuum lines and pressure lines were checked..
Wondering if the car had some gas with ALOT of ethanol in it... which happens alot around here during winter time...
again, I think it's obvious that we tune LOTS of evo's, mostly with flashes and have never seen this before.
BUT, that being said... the target afr's I was using, would put a similarly equipped car into the 9's at wot at only 21psi...
hmmm.
cb
We were using the wideband in the car AND on our dyno...
I had tuned two cars earlier in the day, and it read spot on..
the AEM UEGO in the car was reading the SAME as the Innovate on our dyno (about .1 of afr off).....
we looked for exhaust leaks and could not see or hear any... all of the vacuum lines and pressure lines were checked..
Wondering if the car had some gas with ALOT of ethanol in it... which happens alot around here during winter time...
again, I think it's obvious that we tune LOTS of evo's, mostly with flashes and have never seen this before.
BUT, that being said... the target afr's I was using, would put a similarly equipped car into the 9's at wot at only 21psi...
hmmm.
cb
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yep, the fact that you couldn't richen it up on the dyno but it's pig rich on the street is pretty bizarre.
what fuel pump is on the car? maybe it's having issues or not getting enough voltage to it under some circumstances.
what fuel pump is on the car? maybe it's having issues or not getting enough voltage to it under some circumstances.
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the only other thing i can think of, is the fuel pump possibly not getting a good seal in the housing... but ive NEVER seen that before, and everything looked fine, i put the pump in myself.
Ill have to ask John if filled the tank up after he left the shop.
cb
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From: Spec-Ops Motorsports, Fayetteville, NC
Hey chad... my buddy had a similar situation like this and it turned out that he wasnt building the fuel pressure he should have been at WOT due to the o-ring that helps seal the pump into the housing had the smallest of hairline tears in it and it wasnt sealing properly. Replaced the o-ring and she was fine.
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yeah, like isaid, i suspected something on the pump, but didnt find anything wrong..
i wanted to COMPLETELY top off the tank to see if that changed anything... but we were running out of time..
cb
i wanted to COMPLETELY top off the tank to see if that changed anything... but we were running out of time..
cb
