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SPFI vacuum question before insta


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I am seeking install the Spfi on my carbed EA82 and does anybody know if the SPFI system needs to be so "vacuum sealed" that it requires the oil spout cap to be also sealed..for ex: my MPFI turbo will not run unless the cap is tightly on or the PVC hose also being sealed up...I might have to much back pressure (possible worn rings)to install the FI system, if it requires complete sealing well I guess in this case just get the carb rebuilt

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Since the PCV system on the FI cars is completely closed, yes. Opening the oil filler cap creates a large vacuum leak.

 

That doesn't mean you have to use a closed PCV system. You can seperate the PCV system from the intake and use an air breather for the two valve covers, and plug up the PCV valve. This, in effect, fixes that problem, though it opens up a whole can of worms with emissions. Dunno what they're like in your area.

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I will experiment with that idea.. Thanks

Since the PCV system on the FI cars is completely closed, yes. Opening the oil filler cap creates a large vacuum leak.

 

That doesn't mean you have to use a closed PCV system. You can seperate the PCV system from the intake and use an air breather for the two valve covers, and plug up the PCV valve. This, in effect, fixes that problem, though it opens up a whole can of worms with emissions. Dunno what they're like in your area.

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spfi has to be very tight. one little leak is 10mpg and a moody idle.caused mine to buck and take off fast randomly.The charcoal canister should be monitored too,When all vacuum is good and sealed, and there still seems to be a problem--

also any changes to the system means waiting alot longer than realtime expectations. I pushed my "luck" and changed all kinds of stuff, including leaving egr out forever, with a "cel" light on the same.The ecu was very stubbornly slow curve of learning extra or different. It stays good now at 38mpg (average) on my 156k mile sube.Good Luck. It is a good durable upgrade. :)

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