First post...A few quick EFI questions

[Lars]

Re: First post...A few quick EFI questions

A few more things...

That 6 pin Explorer mass air meter includes the ACT, which is why there are 6 wires. It's actually a pretty good air meter. Unfortunately the transfer function (mathematical relationship between sensor output and airflow) is somewhat different that what the EEC-IV computers (for example, an A9L) are expecting. It's not that far off though; you could try it and see how it works. I've experimented with different ACT sensor locations on my frankenstein Explorer 5.0 installation. I couldn't discern a difference no matter where it was, and that included looking at datalogs from my user-programmable chip as well as seat-of-the pants impressions.

As for the ECT, I drilled/tapped the heater tube fitting as you described, down into the top of the fitting. Did that because the stock Explorer location caused the ECT sensor to interfere with the distributor. I have since gone to a bastard EDIS (distributorless) system that allowed me to put the sensor back in the stock location. I've also datalogged the ECT output. The ECT sensor temp reading tracks the water temp measured with a separate gauge and the computer goes closed-loop when the temp reaches the correct value, which of course I've forgotten. That despite the cooling system not being full flow. The ECT is mounted so close to flowing water in the lower intake that it apparently isn't an issue.

When I first got the engine running, I substituted Mustang 5.0 mass air parts for all the Explorer electrics, with an A9L processor, stock Mustang mass air meter, Mustang 5.0 TFI distributor, but with the Explorer intake & throttle body, gt-40p heads (stock) and so on. My current setup is all Explorer sensors including a 6-pin mass air meter with the same A9L and a Tweecer to turn off the TFI and turn on the EDIS. I like the Explorer stuff better.

[jamesroney]

Re: First post...A few quick EFI questions

A few more things...(snip)
The ECT sensor temp reading tracks the water temp measured with a separate gauge and the computer goes closed-loop when the temp reaches the correct value.

So do you contend that the ECT input is solely to enable the closed loop strategy? I would have thought that the ECT analog input would have had some proportional effect, otherwise a thermistor would seem to be more cost effective.

I would also *guess* that the ECT would provide over-temp data to enable a different timing/fuel map in the event of excess temp.

But that's only a guess.

I run the stone stock 1993 Cobra induction. But the idea of EDIS is very attractive. I THOUGHT that I would need an OBD-2 ECM to make that work. Can you tell me more about the interface to eliminate the TFI?

Thanks!

[72bronc0]

Re: First post...A few quick EFI questions

Thanks for all your input guys!

So I just measured the stock sending unit and it looks pretty close to the length of plug ugly's after the mods. Here's some pictures. I plan on cutting out the flange and surface it on a piece of glass, then weld it to my tank.

jamesroney- I'll see what I can do on the tank for the exhaust relief. I have an idea that I think will work. If you have any other pictures kicking around of the BC tank I may be able to use them as a guide for where I can add width and length without making it too deep. It seems like those tanks are really deep but I've never seen one in person.

Lars,
Good info thanks. I think I'll give my explorer MAF a shot. If it doesn't work I'll buy the mustang one. Then again, I may not even know the difference. Thanks again.

[SonicDonkey]

Re: First post...A few quick EFI questions

I build an aluminum take with steel skid when I stretched the rear in my EB. Things I would have done different are optimized design for maximum gallons, a true pick up sump/trap and used the intank pump. I kind of got in a hurry and got to the point where I figured it will work. I do plan to build another some day, just a ways down the line. Pics for ideas

[Lars]

Re: First post...A few quick EFI questions

So do you contend that the ECT input is solely to enable the closed loop strategy? I would have thought that the ECT analog input would have had some proportional effect, otherwise a thermistor would seem to be more cost effective.

I would also *guess* that the ECT would provide over-temp data to enable a different timing/fuel map in the event of excess temp.

But that's only a guess.

I run the stone stock 1993 Cobra induction. But the idea of EDIS is very attractive. I THOUGHT that I would need an OBD-2 ECM to make that work. Can you tell me more about the interface to eliminate the TFI?

Thanks!

I'm reasonably sure that the ECT does more than just causing a bit to flip. It's been so many years since I've really looked closely at this stuff. But the ECT information is represented in the processor input file as a function, not a scalar which implies that the processor responds differently depending on ECT output.

It turns out that apparently Ford was well aware of the issues with the TFI control of spark way back in the day. All the Axxx processors have EDIS control built into them, but Ford never implemented the hardware. All it takes is a programmable chip (in my not-so-humble opinion, user-programmable chips that also allow real-time datalogging such as a tweecer RT or Moates Quarterhorse are the only way to go) that give you control of the input file. Then it's a matter of flipping a few bits and the processor will recognize the EDIS module, which essentially replaces the TFI. The easiest way to implement it is to get hold of Explorer front dress, so you can get the "missing tooth" wheel on the harmonic balancer and a cam position sensor. You can build up a wiring harness for the setup using factory Ford parts.

I guess I should do a write-up on what it takes. Just never seem to make time for it, and especially now that my aluminum mistress is on the verge of being able to fly.

I should also point out that I'm just an interested amateur. When it comes to tuning using user-programmable chips, there are lots of users that are formidably better qualified to discuss the topic than I am.

[72bronc0]

Re: First post...A few quick EFI questions

I build an aluminum take with steel skid when I stretched the rear in my EB. Things I would have done different are optimized design for maximum gallons, a true pick up sump/trap and used the intank pump. I kind of got in a hurry and got to the point where I figured it will work. I do plan to build another some day, just a ways down the line. Pics for ideas

Nice work. Thanks for the pictures.

[plug ugly]

Re: First post...A few quick EFI questions

Sonic, that's pretty much what I envisioned, just blind nuts sets but that is better. Guess I'm off to the junkyard again.

Would it be easy to extend the pump and pickup to fit a 12" tall tank? Looks like thAt is about 11?

[72bronc0]

Re: First post...A few quick EFI questions

OK here's an update:

I'm working on my tank right now. I built a prototype first and placed the sending unit and pump in it to test the action of the float. The pump sits about .75" above the bottom and the float seems to work well. This is the stock sending unit and pump from a 1996 4 door explorer. I lucked out and found one on ebay for 50 bucks brand new.

I have the stainless shell tacked together but I wanted to see if I was overlooking something major before I go any farther. I realize it seems a bit low below the bumper but the stock one is going away and I'll fabricate one that'll hide it a little more.

I am still going to design a sump area that'll trap fuel and I have a plan for baffles. I tested some perforated stainless in my prototype tank and it almost eliminates any sloshing around.

So far I calculate just over 24 gallons but it's hard to say what I'll actually end up with by the time everything's done. From other pictures I've seen I am not hanging any lower than a BC tank. I could have stretched it a little more and but I didn't really need to. I have a way I can clearance the tank for pipes but mine were ran far enough away that I did not need to in my application. All in all I could probably get 2.5 more gallons out of it.

I also have a plan for mounts which should be pretty slick. It will not include uni-strut.

any comments or concerns? fire away. I am looking for criticism and suggestions. Thanks!!