Would This EFI Work?

I was looking for a EFI system that could be retrofitted to our sixes and came across these sites:

http://www.fordfuelinjection.com/

http://www.slantsix.org/articles/dibias ... ersion.htm

The first site is about retrofitting Ford systems, the second GM. The common theme is the use of a MAF (Mass Air Flow) instead of a MAP (Manifold Absolute Pressure) sensor.

MAFs are capable of telling the computer directly how much air the engine is using. To some extent this allows the computer to compensate for any modifications done to increase volumetric flow thru the motor (new cam, headers). MAF system would be easier in that, with the right sized system, no reprogramming would be necessary.

MAP systems, on the other hand, compute air flow indirectly. The MAP system has a bunch of fuel and ignition maps just like the MAF computer, but it calculates air flow based upon sensor inputs for RPM, throttle position, engine operating temperature, inlet air temperature, atmospheric pressure and most importantly manifold pressure (vacuum). This system is the most popular one sold in the aftermarket; Megasquirt being an example. The downside is that they need to be programmed, usually with a laptop, and if any performance changes are made, they would have to be reprogrammed.

I guess my question is, would the MAF system be better for the ones of us who don't want to mess with tweeking an EFI?

If i recall, the latest version of MS can handle MAF inputs and MAP inputs and has a logic function on when to choose which input for determination of fuel. It's under the Microsquirt but the information says it's applicable for MegaSquirt as well.

MAF still requires some programming and tweaking, just doesn't require as much retweaking as you make future performance modifications.

I have yet to talk to (in person or online) anyone that has installed a 'plug and play' 'self adjusting' efi system. Im not saying its impossible but if it was that easy I would think I would have seen or heard about how easy and great they are from people other than the ones selling em.

There are pluses and minuses for both systems.

The MAF systems that I have read about are multi port injected and would required installing injector bungs in the intake manifold; not as easy as a TBI all-in-one unit on the MAP system.

The articles also state that the intake system plumbing for MAF has to have no leaks in order for the system to measure the correct air volume; no such concerns mentioned for MAP.

I've read somewhere that a MAF system can compensate up to 20% for displacement discrepancies without adjustment so a complete EFI system from a 3.8L would work on a 200 or 250; a MAP system from the same 3.8L would have to be reprogrammed.

I agree with you, fordconvert, that the aftermarket MAF systems are not always 'plug and play' self adjusting', but if you stay within their limitations they are easier to retrofit than a MAP.

The MASS air is the best solution...my experience working on the MAF ECM and doing mods to the engine will not bother what you install...Ford was very smart with their MAF or MASS AIR as it is also known...how this system works is that it measures air going in and adds the fuel required, then takes a EGT reading and is always adjusting...so whether you install a huge cam or change the manifold profile or install a set of headers...the system will self adjust...it only takes a few moments to find out what's going on before it will re-learn how to run the engine with the proper AFR...the guy who sold me the Ford Racing EFI harness and ECM told me that he took the stock EFI off a 5.0 and installed the whole system on a 390 Y-block with aftermarket racing parts, he told me that it dyno'd at 650+HP!(he did use bigger injectors)...now for a stock system to support that was impressive...he also told me that he has not figured out what the Ford ECM limit was in HP...as long as the injector duty cycle was not pushed it will work with just about anything that runs...I have thought about using the Ford MASS AIR system but decided on the Holley carb set up first, but it doesn't mean I'm not going to do it later...this would make a very nice addition to my turbo mod as it will automatically adjust timing and fuel curve...Ford had two different ECM's, one fired bank/bank while the HO used sequential EFI.

As for the GM MAF system, I'm not sure if it has a self learning mode...it might be set to just the perimeters of the 3.8...good luck.

Falcon Ranch,

Is the Ford Racing EFI harness you have set up for six or eight cylinders? If it's eight, how are you going to adapt it for six? If it is a batch fire system, can you just not use two of the injectors? What is the ECM model and code numbers?

Sorry for all the questions. I've been looking at wiring harnesses/ECMs for the 87-93 V8 Mustangs and was wondering if they could be adapted to our sixes. Looking as the schematics on fordfuelinjection, they appear to be the sequential harnesses, which wouldn't work, but batch fire harnesses might.