Explorer 5.0 EFI swap with RJM Harness - Way more info than you ever thought possible

[Viperwolf1]

Haha, yeah that 55mm MAF is super tiny compared to the explorer 70mm. Hmmmm....
Now what about the TB, I am using the Explorer TB and I know others are, isnt it larger than the Mustang?

Yes the explorer TB is bigger. I got a free one with my upper and swapped the throttle lever out w/mustang TB. It even had the vent tube and the TPS swapped right over, no drilling.

 

[needabronco]

http://rjminjectiontech.com/?p=14

About half way down the page.

 

[Viperwolf1]

In the Ford Motorsports catalog (2004) and they sell a 70mm MAF for use w/stock 89-93 computers but you have to use 30 lb. injectors. It looks just like the explorer one with the 4 bolt holes.

 

[RnrdTheFox]

Haha, yeah that 55mm MAF is super tiny compared to the explorer 70mm. Hmmmm....
Now what about the TB, I am using the Explorer TB and I know others are, isnt it larger than the Mustang?

You can get away with the Explorer TB. The Explorer is 65mm. I've been running mine since day one. Never really noticed much about it. Seemed to work well. The other day I got my hands on a stock bin file for a 97 Mountaineer and I pulled it into the Cal edit software that comes with the Tweecer and compared it to the stock setting for the 94/95 Mustang computer that I'm running. They both had a scaler for Throttle Body Air Flow. Stock Mustang was .419 Kg/Hr and the Mountaineer was .580 Kg/Hr. I did notice a slightly better throttle response after changing it. I still want to go back and validate this as I changed some other settings, but they were with the transmission. Maybe Lars can try this since I think he's running an Explorer TB and Tweecer....

I'm not saying running a bigger MAF won't work, it probably will. It just won't be working the way it's supposed to be working. I guess I could go outside and hook up the explorer MAF and see what the Air/Fuel ratios change too.

 

[Tito]

Hahahha, you'd be the man!!! Come on, do it, do it!!! ;D ;D

I really appreciate the input here!

 

[lars]

You can get away with the Explorer TB. The Explorer is 65mm. I've been running mine since day one. Never really noticed much about it. Seemed to work well. The other day I got my hands on a stock bin file for a 97 Mountaineer and I pulled it into the Cal edit software that comes with the Tweecer and compared it to the stock setting for the 94/95 Mustang computer that I'm running. They both had a scaler for Throttle Body Air Flow. Stock Mustang was .419 Kg/Hr and the Mountaineer was .580 Kg/Hr. I did notice a slightly better throttle response after changing it. I still want to go back and validate this as I changed some other settings, but they were with the transmission. Maybe Lars can try this since I think he's running an Explorer TB and Tweecer....

I'm not saying running a bigger MAF won't work, it probably will. It just won't be working the way it's supposed to be working. I guess I could go outside and hook up the explorer MAF and see what the Air/Fuel ratios change too.

I too have been running an Explorer 65mm throttle body since Day 1 with no difficulties. The Explorer t/b is just a permutation of Ford's own FRPP 65mm throttle body, sold as an aftermarket hot rod product for the 5 liter Mustang.

One thing to be aware of is that the Caledit software has the wrong units on the T/B Airflow scalar. The correct units are lb/min, not kg/hr. That's documented somewhere on the Tweecer board. With my cam combo mine is up to 0.9 lb/min and I've got a rock steady idle and great tip in performance. That was after a zillion hours of datalogging, tuning the MAF curve, more datalogging, etc until it stabilized. I highly recommend the EEC Analyzer and Binary Editor software, available here: http://eecanalyzer.net/
Mike Glover has a great product in the Tweecer, but others have better software.

I need to open the EEC Analyzer software and plot the 55mm Mustang vs. 70mm Explorer MAF transfer functions so people can see how they differ.

 

[lars]

One more potentially useful factoid:

The last couple of years of the Explorer 5.0 shared a plastic 70mm MAF with V6 Ranger pickups of the same years. Dimensionally they are the same as the aluminum MAF, but with one key difference: the ACT sensor is built into the electronics. The connector thus has 6 pins instead of 4. I'm now running one of them. It's not a huge big deal but it cleans up the wiring a little bit, since now I don't have an ACT plugged into the lower intake, and the ACT wires run with the MAF connector wire. Minor deal, but possibly interesting. What's more, most people have no idea that it's a neat device, so they usually go cheap ;D

 

[RnrdTheFox]

I too have been running an Explorer 65mm throttle body since Day 1 with no difficulties. The Explorer t/b is just a permutation of Ford's own FRPP 65mm throttle body, sold as an aftermarket hot rod product for the 5 liter Mustang.

One thing to be aware of is that the Caledit software has the wrong units on the T/B Airflow scalar. The correct units are lb/min, not kg/hr. That's documented somewhere on the Tweecer board. With my cam combo mine is up to 0.9 lb/min and I've got a rock steady idle and great tip in performance. That was after a zillion hours of datalogging, tuning the MAF curve, more datalogging, etc until it stabilized. I highly recommend the EEC Analyzer and Binary Editor software, available here: http://eecanalyzer.net/
Mike Glover has a great product in the Tweecer, but others have better software.

I need to open the EEC Analyzer software and plot the 55mm Mustang vs. 70mm Explorer MAF transfer functions so people can see how they differ.

Good to know about the scalar units. I've just started to really dig into the computer. How do you like running the 70mm MAF after you got the transfer function mapped? Any noticable performance???

 

[lars]

Good to know about the scalar units. I've just started to really dig into the computer. How do you like running the 70mm MAF after you got the transfer function mapped? Any noticeable performance???

I wish I could say that I noticed a big performance boost, but the reality is no. I wound up with the Tweecer so I could turn on the distributorless ignition features in the A9L, and added the Explorer MAF since at that point it was easy. But the reality is that apart from bragging rights I can't say as I notice much, if any difference. Only a dyno would say for sure. It wasn't a total waste though; I have an aftermarket cam, and I always had some issues with idle stability (surging). After the work with the Tweecer, that's gone.

 

[Dowd]

One more potentially useful factoid:

The last couple of years of the Explorer 5.0 shared a plastic 70mm MAF with V6 Ranger pickups of the same years. Dimensionally they are the same as the aluminum MAF, but with one key difference: the ACT sensor is built into the electronics. The connector thus has 6 pins instead of 4. I'm now running one of them. It's not a huge big deal but it cleans up the wiring a little bit, since now I don't have an ACT plugged into the lower intake, and the ACT wires run with the MAF connector wire. Minor deal, but possibly interesting. What's more, most people have no idea that it's a neat device, so they usually go cheap ;D

Can you run the ranger MAF with the explorer TB and early 90's mustang computer and dist. to avoid tapping and drilling for the ACT?

 

[Tito]

Actually if you run the explorer tube with the ranger MAF adapter you can just use the ACT in the tube, here it is in this pic, just need to extend the wire on the harness.

You can kinda see it there before the bend. You can also run a ricer tube and drill and tap it. I;d have just extended the wire if I had realized the ACT was there on the tube, but then again I am not sure if I am going to use the long tube, I'd rather do without but will try it both ways to see if there is any issue.

 

[needabronco]

Can you run the ranger MAF with the explorer TB and early 90's mustang computer and dist. to avoid tapping and drilling for the ACT?

Wouldn't it be easier and less work to just drill and tap a hole, then rewire your harness to make the ranger MAF work? I'd like to see it done though...

 

[lars]

Actually if you run the explorer tube with the ranger MAF adapter you can just use the ACT in the tube, here it is in this pic, just need to extend the wire on the harness.

Ya, but I think the Ranger MAF to which he refers is the same as the one I have, with a 6 wire connector and the ACT built into the meter. You'd still need the adapter in either case. Mechanically and electrically it will work. But will the computer like it?

 

[Tito]

Wouldn't it be easier and less work to just drill and tap a hole, then rewire your harness to make the ranger MAF work? I'd like to see it done though...

Just sign up for the Drill and Tap tour, its starting with Dave, not quite Spinal Tap but hey it'll save you a couple bucks. ;D

Ya, but I think the Ranger MAF to which he refers is the same as the one I have, with a 6 wire connector and the ACT built into the meter. You'd still need the adapter in either case. Mechanically and electrically it will work. But will the computer like it?

Ahh, I see ;D

 

[Dowd]

Actually if you run the explorer tube with the ranger MAF adapter you can just use the ACT in the tube, here it is in this pic, just need to extend the wire on the harness.

You can kinda see it there before the bend. You can also run a ricer tube and drill and tap it. I;d have just extended the wire if I had realized the ACT was there on the tube, but then again I am not sure if I am going to use the long tube, I'd rather do without but will try it both ways to see if there is any issue.

Thanks so much for all the great info.. Your motor is lookin good. I thought I liked the looks of the cone coming straight out of the tb but the more I see the other pic I am not sure. They both look clean. Just thinking out loud I think either way you run it will look good.

 

[Tito]

I'll need to make a little bracket to support the MAF if I run the tube so it doesnt flop around, that long tube is pretty flaccid :-X

 

[Dowd]

I'll need to make a little bracket to support the MAF if I run the tube so it doesnt flop around, that long tube is pretty flaccid :-X

I won't even go there, too easy..... ohhhh maybe call it the John Holmes bracket.

 

[Viperwolf1]

Tito,
Here are some things I've been working on.
I turned the breather tube in the explorer TB 180 degrees to point toward the oil fill neck. I just stuck a punch inside the tube and gently rocked it back and forth until it broke loose. This allowed me to use the mustang vent tube that I already had.
I'm using EGR on mine. I put an extra nipple on the back of the lower manifold where a plug would have been to draw coolant from both banks equally. I figured this would keep the coolant flowing and potentially prevent trapped air in the system.
I finally received the Autozone heater hose that I talked about previously. I needs a little trimming but is going to fit great with the mustang heat tubes and is the perfect length to reach the heater. I hope to end up with a clean factory installed look.

 

[70_Steve]

That second picture reminds me of something I still need to find. Sorry for the hijack, but does anyone have part numbers, etc for all the PCV stuff that goes in the rear of the manifold? All I've got is the big grommet. I understand there's a screen pack that goes underneath, and I don't know what else. Also, what PCV valve do you guys use?

 

[Viperwolf1]

PCV is motorcraft PV98. I don't know the number for the screen but I know it's available. I bought a new grommet at the local mustang shop and they asked if I needed the screen. I just washed out the old one.

Correction: EV98 is the PCV