Sequential fuel injection (sefi) on I6?
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Sequential fuel injection (sefi) on I6?
I run a stock 1989 E350 van 300 I6 with C6 tranny and 206,000 miles. On average I get 12mpg hauling 3/4 of a ton of sound system over pretty level highway and I am not complaining. Has anyone else out there ever wondered why ford never put a sequential efi system on this engine? Or did they? It seems kind of wasteful with the efi system on this engine to pulse the injectors in 2 banks of 3 and to pulse them on every rotation of the crank instead of one pulse per cylinder per intake stroke. My truck works great as it is but could this be a much more fuel efficient platform? Or did ford engineers have a real good reason to not put sefi on this engine?
Hotshot
Joined: Aug 2002
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From: BC, Canada
I might be wrong but I think that when they went to EEC V in 1995 they also went to SEFI.
I would assume that they stuck with bank fire as long as they did because it was cheaper.
I'm not sure that SEFI always made too much difference. The fuel that is injected just sort of sits at the intake valve and waits for it to open. When it gets there probably doesn't make a huge difference. One big shot of fuel vs 2 small shots.....does it really matter? I'm not sure.
I would assume that they stuck with bank fire as long as they did because it was cheaper.
I'm not sure that SEFI always made too much difference. The fuel that is injected just sort of sits at the intake valve and waits for it to open. When it gets there probably doesn't make a huge difference. One big shot of fuel vs 2 small shots.....does it really matter? I'm not sure.
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From: Sussex County, DE
SEFI only matters at the tailpipe. I have more experience with SEFI on GM vehicles that Fords, but I know that GM's 3800 V6 performs virtually identically wheter in SEFI or just PFI mode. It defaults to batch fire if the cam sensor fails, and with the exception of a slightly dirtier (still very clean) exhaust, and perhaps a small decrease in fuel mileage (about .25 MPG) there seems to be no discernable difference. The extra complication with SEFI is not worth the slight benefit unless you are looking for the utmost in performance, because it is transparent to the end user. BTW, 1996 (OBD II) and 1995 Cali trucks are SEFI.
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Thanks for the thought provoking replies. I'm glad to hear that the difference between sefi and bank firing is negligible. Especially interesting about the GM engine reverting to bank fire if the cam sensor fails. Thanks again.
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Joined: Oct 2002
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From: Grande Prairie, AB
The idea with SEFI is to have the mist right there, fuel mileage is not key in this situation. POWER is. More of an atomized fuel mixture is the key to power, fuel sitting at the valve is useless, might as well put a carb on it. But in an engine operation as you may know (intake, compression, ignition, exhaust) happens real fast. so SEFI is not too big of a deal when everything is major happening fast, barely has time to sit at the intake valve.
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