Sniper 2GC EFI swap (1 Viewer)

jmcclusk

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Lots of Sniper builds, but haven't seen many 2GC large bore snipers so here is what I did. Advantage of the 2GC is it looks better than the 2300 in this situation and it fits directly to the stock air cleaner assembly. I designed and machined an adapter between the manifold and 2GC. I still used the carb insulator to try to keep the heat down. Used a RobbMc performance powersurge pump being fed by stock pump. Stock air cleaner assembly. AN braided lines. Stock distributor, but basic recurve springs installed.

Still tinkering with the settings and tuning, could use some pointers for what people did for timing. Manual says 7°, but some other posts say more like 12°. Seems to run better at 12 to 14, what have you done here?

Also, the Sniper AIC seems to be a little slow to react. The feedback loop is slow enough it revs up over the target rpm and then dumps back down 100 under and keeps surging gently like that. If you stick your finger in the sniper and plug the AIC passage while its running it flattens out perfectly smooth... If I bring the idle screw in so it is idling above the target idle the AIC goes to 0 understandably and it smooths out, but if you screw it out so the AIC is anywhere positive it surges up and down. I have checked for an air leak, but none found. What do other people do here?

Have other people got better gas mileage with snipers? it doesn't seem to help mine, but I'm still tuning it...

thanks,
John

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Joined
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You won’t get better gas mileage by going to efi in fact it might be slightly worse. Unless you specifically tune fore fuel mileage at the cost of everything else
 

MoaByte

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It looks super sanitary. You are probably going to need to dink with the AIC a few times before you find a happy place. It's imperative that you have even vacuum and your valves are adjusted properly to get a good tune. It seems that if all is perfect with your engine and fuel delivery and return, it's still necessary to fine tune from a laptop to prevent stalling on a cool motor during down shifting.

Timing is a whole can of worms because desmogging. You don't want to exceed 28.5° total advance but that doesn't mean you can run that much because of the advance curve. I'm having pretty good performance using the HEI and I believe I'm set at 11° static.
 

wngrog

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Nice job. I’ve installed 5 2GC large bore but all of them have been on FJ40s.

Mosley Motors sells the adapters that I used. Yours looks sweet. Nice work.

My latest.

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jmcclusk

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Joined
Oct 22, 2011
Messages
171
Location
Portland OR
Looks great. How did you mount the surge tank?
thanks! I mounted it to the firewall kinda nestled under the wiper motor and between the AC lines/washer fluid tank. its pretty close, but worked out fine. I put a small block under the lower screws because the firewall isnt flat there, top screw was on a protrusion.
Do you have a cap on the 3/8” bung in the center front of the 2GC?

Sure sounds like a vacuum leak with the surge.

Did you follow the IAC initial setup in the manual?
I have a cap on the vac nipple on the side nearest the firewall, and am using the vac nipple on the radiator side for the distributor advance. Not sure if these are the ones you mean, I don't see any others. I agree it is acting like a vacuum leak, I can't find one though. Yeah I did the IAC initial setup in the manual. Your setups look gorgeous!

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