fuel injector firing order

Topic: fuel injector firing order (Read 1901 times) previous topic - next topic

fuel injector firing order

March 08, 2005, 05:07:17 PM

question to someone,,,,,,, anyone,,,,,,,,,,,,,, do the six cyl sefi injectors fire once every go around like the v8's or do they fire in pairs like on the 4 cyl?,,, i need to know and i dont have a schematic of the 88sefi.

Re: fuel injector firing order

Reply #1 – March 08, 2005, 05:44:49 PM

According to the '88 EVTM they're bank-firing.
Here'z a diagram...

Re: fuel injector firing order

Reply #2 – March 08, 2005, 06:31:56 PM

I alwasy thought they were SEFI, so I had to check Carmen on this one, but as usual he's correct.

BTW inj 1, 2 & 4, fire on the first shot, followed by 3, 5, & 6. Which leads me to this obversation.... Ford calls these systems bank fire, so naturally everyone ASSumes they mean right bank, left bank, not so. They are talking banks(wired together) of injectors, GM uses the more approiate term batch fire...

Re: fuel injector firing order

Reply #3 – March 08, 2005, 08:11:10 PM

Actually, Tom, until Scott asked that question and I looked it up, I always thought they were SEFI as well. I was surprised when I looked at Mitchell ONDemand and saw it, so I had to verify it in the EVTM. I've just checked, and in '89 they were SEFI. Guess bank firing was a one-year-only thing for the 3.8

Re: fuel injector firing order

Reply #4 – March 08, 2005, 09:29:40 PM

And I just checked the EVTM on my 3.0 V6 '88 Aerostar... batch fire

Re: fuel injector firing order

Reply #5 – March 08, 2005, 10:35:14 PM

Yeah,, what you guys said,, i was under the same confused impression from all the looking up i did.

I was interested in the fact that my 87 CFI EEC could be wired to handle six injectors if heads were worked of coarse and the injecters mounted in the intake were wired like the 88. Of course im not sure of the whole "reflective resistance" increase thing either.
no,,, wait,,
or would that be a reflective resistance *decrease* cause they would infact be in parallel,,humm.
instead of one injector off pin 58, there would be three in parallel.

thank you thunderchicken,,and you tom :grinno: . Gotta love that Mitchell ONDemand but it aint cheap.

This took care of my question. It's interesting that the 88 year harness splits up the fuel like it does on its so called bank fire alternating back and forth.

tom,,
How did you figure out that on the 88 engines, the injectors cross fired like they did. It would have been very easy for me to misinterpert the schematic. The way the schematic reads,, it appears to be true bank fire., left side then right. Maybe the part they dont tell you on the schematic is that inj number x goes to cylinder y., not inj x goes to cyl x.

it seems to me that the 88 engine could in fact be more fuel efficient it it were SEFI instead of batch or bank fire.

batch fire on a gm means a group of injectors firing together?

so would all of the following be correct to you both?

2.3 L engine (bank fire)
inj 1, 2 pin 58
inj 3, 4 pin 59

1982 - 87 3.8 L engine CFI (Bank fire) including some earlier 5.0's with larger CFI
inj 1 , pin 58
inj 2 , pin 59

1988 3.8 L engine 6 injectors (bank/batch fire)
inj 1, 2, 3 pin 58
inj 4, 5, 6 pin 59
*inj 1,2,4 fire on first shot
*inj 3,5,6 fire on second shot

1989+ 3.8 L engine 6 injectors (sefi)
pinouts,, not sure

5.0L 1986 + (sefi)
inj 1 , pin 58
inj 2 , pin 59
inj 3 , pin 12
inj 4 , pin 13
inj 5 , pin 14
inj 6 , pin 15
inj 7 , pin 42
inj 8 , pin 52

Re: fuel injector firing order

Reply #6 – March 09, 2005, 02:48:34 AM

Scott I checked the '88 EVTM for the info.... It and the Aerostar EVTM are the only '88 factory info I have. Except for the '87 EVTM, I do have a full set of '86 and '87 shop manuals.

Basically you are correct on your pin-outs except for the '88 V6...

inj 1, 2, & 4 --- Pin58

inj 3, 5, & 6 --- Pin 59

Injectors wired in paraell will fire at the same time, no way to alternate inj 3 & 4..

For the '89 up with SEFI (From the Probst manual How to Understand, Service and modify Ford Fuel Injection). He lists the '88 3.8 in with the '89-93, but I have found other mistakes in this manual(mainly omissions).

inj 1-- pin 58
inj 2-- pin 59
inj 3-- pin 39
inj 4-- pin 35
inj 5-- pin 15
inj 6-- pin 12

And while I'm at it... 1988-1990 E/F series and Bronco batch/bank fire... (Probst again).

inj 1, 4, 6, 7-- pin 58
inj 2, 3, 5, 8-- pin 59

I'm sure this applies all the way back to the '85.5 F series(yes Port inj was actually introduced mid year on the F series, before the cars). The Probst manual begins at '88. I also have his '80-'87 manual, but its loaned out to a buddy that has a 85.5 F-150. He's building a fresh roller HO 5.0 for it, so we are going to convert to SEFI using a '86 or '88 SD Mark-VII EEC(gonna try both to see which one runs best).

Re: fuel injector firing order

Reply #7 – March 09, 2005, 11:31:15 AM

Quote from: TurboCoupe50

Basically you are correct on your pin-outs except for the '88 V6...

inj 1, 2, & 4 --- Pin58

inj 3, 5, & 6 --- Pin 59

strange. the schematic sys different.

ill assume you mean cylinders instead of injectors and if so,, maybe the following would be more clear to your point.

inj 1,2,3, pin 58eec to cyl 1,2,4 respectively
inj 4,5,6, pin 59eec to cyl 3,5,6 respectively

if thats what you mean then your obviously correct and the schematic is correct but the injectors do no say which cylinder they operate.
Perhaps in this crossfire instance, the injector should also be labled with the cyl number if it differes with the injector number,,agree?

Re: fuel injector firing order

Reply #8 – March 09, 2005, 11:51:19 AM

Yea I just ASSumed you would be thinking cyl #1 = inj 1, cyl #4 = inj 4, etc. That is how the EVTM shows the wiring to the injectors.

Re: fuel injector firing order

Reply #9 – March 09, 2005, 11:55:58 AM

or to solve the mistery have someone with the 3.8 sefi go out and see what injectors go to what cylinder and report back here so its cleared up. but like tc50 says to assume that the way there labled is the cylinder they are in.

Re: fuel injector firing order

Reply #10 – March 09, 2005, 03:01:42 PM

Quote from: Cougar8775

or to solve the mistery have someone with the 3.8 sefi go out and see what injectors go to what cylinder and report back here so its cleared up. but like tc50 says to assume that the way there labled is the cylinder they are in.

Sounds like a good idea... probably won't take more than a hour or two... :disappoin :disappoin :disappoin

Re: fuel injector firing order

Reply #11 – March 09, 2005, 04:17:55 PM

Quote from: TurboCoupe50

Sounds like a good idea... probably won't take more than a hour or two... :disappoin :disappoin :disappoin

gotta love those upper intakes.

this turned out to be a really good thread. Thanks for the help guys. It opens up the possiblity of the CFI to batch fire conversion possibility if the 4.2 short block parts were added / heads worked ect ect. as well as injectors mounted in the intake.

What injectors to use would probably be a hit or miss thing depending on the displacement / airflow numbers of the engine.

It would be nice to have main caps on the 6cyl custom made on number 3,4 caps so they were 4bolt mains. The block would have to be drilled but i dont know if the block design would allow for it.

for all its worth,, it would be even nicer to make 4bolt mains on the 5.0 but leave the first and last main as a two bolt since they a little more complicated in design.

I'd say leaving the mains on the front and rear as stock would be cheaper. Having the inbetween mains custom made would not be expensive cause its just an hunk of metal with a bore diameter, specific width and two holes on each ear.

Re: fuel injector firing order

Reply #12 – March 09, 2005, 05:20:09 PM

Scott, too bad this didn't come up a few years back, I know Ronnie gave his running '88 3.8, wiring, EEC, etc. to the junk man when he did the 5.0 swap on his Bird. A ride to Newport News would have been a gold mine for you...

Re: fuel injector firing order

Reply #13 – March 09, 2005, 10:33:18 PM

yeah, they're a dime a dozen for the most part.,, at least for now.
im just collecting information during my poorman days here. Its a good time to do research so when i finally jump into something of an upgrade, i wont be so blind.

I just cant help but think up things like this cause the 6cyl is much lighter combined with a T5 so there just might be some hope. Hope without the investment that has been required of a 6 to compete with an 8.

perhaps i should keep dreaming :giggle:

One things for sure,, when work does come (real work) you guys will know exactly what ill be doing.

SO,,,,,,,,did i raise your eyebrows about the 4bolt main thing?
this topics starting to drift, maybe i should stop.