EFI systems
Posting Guru
Joined: Dec 1999
Posts: 1,903
Likes: 2
From: Copley, OH
The SD systems are multi-port but they're batch fire. In the case of your V-8, that's 4 at a time: left bank-right bank-left bank, etc.
Sequential systems fire 1 injector at a time in the same sequence (but at a different crank angle) as the ignition. There has been some discussion as to whether all MAF systems are sequential. I believe that they are but others have disagreed.
Sequential systems fire 1 injector at a time in the same sequence (but at a different crank angle) as the ignition. There has been some discussion as to whether all MAF systems are sequential. I believe that they are but others have disagreed.
Post Fiend
Joined: Oct 2003
Posts: 6,214
Likes: 13
From: New Jersey
its easy enough to tell if its batch fire, bank fire, or true sequential fire.
Disconnect the injector harnesses both sides and using a ohm meter determine if the injectors are seperate, parallel, or a combination.
Batch, all of the injectors would be in parallel, bank you'd have 4 and 4, and sequential, they'd all be independantly wired with a common ground.
The only thing I don't know off the top of my head is if Ford does this exactly like GM cars, where the injector harnesses are wired to match the injection method.
its possible Ford might have everything seperate, until it reaches the ECM, where it bridges injectors and banks of injectors. Would suprise me though as it costs additional money for the extra wires. With corporate accountants and all...
Disconnect the injector harnesses both sides and using a ohm meter determine if the injectors are seperate, parallel, or a combination.
Batch, all of the injectors would be in parallel, bank you'd have 4 and 4, and sequential, they'd all be independantly wired with a common ground.
The only thing I don't know off the top of my head is if Ford does this exactly like GM cars, where the injector harnesses are wired to match the injection method.
its possible Ford might have everything seperate, until it reaches the ECM, where it bridges injectors and banks of injectors. Would suprise me though as it costs additional money for the extra wires. With corporate accountants and all...
Lead Driver
Joined: Nov 2002
Posts: 9,557
Likes: 44
From: Concord, NC
Speed density F-series trucks are multiport injection since there is an injector at each cylinder, and feature batch/bank fire (batch and bank are the same thing, just different name). Injectors 2,4,5,6 and 1,3,7,8 are grouped together as the batches or banks. If you look at the firing order for both the 302 and 351, each bank of injectors' corresponding cylinders are all next to each other in the firing order. Ex) 1-5-4-2-6-3-7-8 for the 302 and 1-3-7-2-6-5-4-8 for the 351. If the harness is like the one on my '87 302, the injectors will all be tied together at the harness, but regardless of where they are tied together, you will still get continuity between batched injectors. Bank/batch one is pin 58 on the computer, and bank/batch 2 is pin 59. There is a common power wire to all injectors (batch and sequential), and then they are activated when the computer grounds the wire on the other side of the injector.
All MAF F-series trucks were sequentially injected. Someone said that 4.0L rangers are batch fire with MAF, but I do not know. As StrangeRanger said, sequential injection fires the injectors one at a time when the intake valve opens for that cylinder. This method is supposed to give a little better fuel economy and throttle response.
All MAF F-series trucks were sequentially injected. Someone said that 4.0L rangers are batch fire with MAF, but I do not know. As StrangeRanger said, sequential injection fires the injectors one at a time when the intake valve opens for that cylinder. This method is supposed to give a little better fuel economy and throttle response.
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