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Fuel Cut With Light Throttle, Mbc


irf

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hey guys, i'm running an mbc set at 14psi with the standard ecu. when i go full throttle i have no problems at all, but when i go maybe 30-40% throttle in fifth gear it wants to cut out.temperatures here at the moment are quite cold, which i've read on here makes it worse.

now after doing some searches i found that this happens to a lot of you and a lot of you were working on solutions. has anyone found a solution to this, wether its spark plugs, the gaps or wether an uprated fuel pump would fix this?

any help appreciated guys.

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Yeah, it's load based. My best guess is this... the ECU sees the MAF load at nearly maxing out (on stock programming) however the TPS is only reading 30-40%. That'd be reason enough for a spark/fuel cut.

Solution... none really, I've tried tons of things. Could probably just hack the MAF, put it in a larger housing.

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I was running 15+ psi in the summer/fall, then when it started to get cold my ECU began acting up and cutting out. I lowered it to between 13 and 14 psi and it went away. Not as much power, but ah well....

I don't think running lean is the problem javadoc- my car still dumps in fuel and keeps the AFRs in the high 11s/low 12s.

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hey guys, i'm running an mbc set at 14psi with the standard ecu. when i go full throttle i have no problems at all, but when i go maybe 30-40% throttle in fifth gear it wants to cut out.temperatures here at the moment are quite cold, which i've read on here makes it worse.

now after doing some searches i found that this happens to a lot of you and a lot of you were working on solutions. has anyone found a solution to this, wether its spark plugs, the gaps or wether an uprated fuel pump would fix this?

any help appreciated guys.

Just to disagree with everyone, Since i've been running a MBC on many cars not just my volvo, I recommend hooking up temp boost gauge, I bet you are not hitting FCO due to load.

I suspect that you are overboosting at part throttle. MBC's are horrible at controlling mid boost if they are the bleeder type.

I won't go in to more specifics because I'll be bashed again... before you do anything do what i suggested.... If that is the case you can lower the boost, or something I found that worked was add another bleeder valve between the boost controller and the wg. Let that one bleed off in to the intake. After doing that on my supra I was able to hold a stead boost at part thorttle and full throttle... .

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