ECU Issue for GT40/Explorer Swap

[fivelstang4]

So a few months ago I did the GT40/Explorer swap on my Colony Park. At that time I installed a Mark 7 ECU. I have been chasing a erratic idle, eating gas like it was going out of style. After many items being replaced I narrowed the problem down to the Lincoln ECU. I installed a Mustang DA1 ECU yesterday and that seemed to have fixed both issues above. Now I know that the Mustang ECU cant control, not a huge issue. I also noticed my horn doesn't work and it did before, anyone else had that problem?

Anyone else had any trouble with the Lincoln ECU and using it for this swap? I seem to recall one other person having a similar issue were the car wouldn't run right with the Lincoln ECU but cant locate it now.

[sly]

check fuses. if the horn is on the same fuse as cruise like it is in my 88, that could be it. You may have the same problem I was having with the horns being old and worn out and drawing too much current. Or the ECM grounds one of those pins that's used for the cruise and blows that fuse.

[mcninetyone]

I did a GT40/Explorer swap using a Mark 7 ECU in a 91CV, and have had no problems at all, car runs perfect.
You may want to try an ECU from another Mark 7.

[pantera77]

Some people have problems, others don't. Really seems to be no rhyme or reason.

[GM_Guy]

May as well open up the ecu and see if the caps have puked their guts.

Alex.

[gadget73]

You may need to de-pin the ECM connector where the cruise wiring goes. Possible something in there caused the fuse to blow since the cruise powers through the horn circuit. you'd be looking at these pins:


Pin 2: Brake ON/OFF. . . . . . . . . . . . . Light Green
Pin 35: Speed Control Vent Solenoid. White / Pink
Pin 38: Speed Control Vacuum Solenoid. . . . . Grey / Black
Pin 39: Speed Control Command Switch Ground. Light Blue / Yellow
Pin 41: Speed Control Solenoid (+) . . . . . . Orange / Yellow
Pin 50: Speed Control Command Switch (+) Light Blue / Black


Those have no function on a Mustang ECM.

The way I fixed my stupid cam/engine/ECM mismatch crap was to go mass air. Runs much happier now.

If you'd like to get fancy and retain the cruise, you can piggy-back the stock ECM in there to handle those functions. Check out part 2 of this, it will work the same way.

http://www.lincolnsonline.com/tech/00077.html

[86VickyLX]

If you did explorer HO swap, and it's not running right, double check that the O2 sensors were not plugged in wrong sides. Been there, done that. Only discovered that years later after I converted to Mass air, and had a datalogging device hooked up to the computer.

[fivelstang4]

If you did explorer HO swap, and it's not running right, double check that the O2 sensors were not plugged in wrong sides. Been there, done that. Only discovered that years later after I converted to Mass air, and had a datalogging device hooked up to the computer.

I am installing brand new o2 sensors in it today, I will make sure they are plugged in the correct sides

[fivelstang4]

A few more questions while all you are posting in here

what fuel pressure are you running? I already have an adjustable FPR but it doesnt have the hookup for a vaccum line, is this an issue?

What base timing are you running?

Also what ohm do you have your Throttle Position Sensor set at?

[BigT]

Some people have problems, others don't. Really seems to be no rhyme or reason.

I think I'm having a similar problem with my Mustang GT HO ECM. After the changing out coolant and throttle sensors, I'm getting a good idle now. However, I’m lucking if I get 15 mpg. I’ve been looking at a Megasquirt ECM for better engine control (http://www.diyautotune.com/catalog/m...-50-p-524.html). Maybe it will help with your problem as well as mine. A little pricey though. Has anyone tried them?

[sly]

Megasquirt is really good and will support ANY upgrades you can throw at these things (short of running a 15K rpm F1 racing engine of course). It's well worth the money if you're really going to build up some stuff. I do think it may require a mass-air sensor though... but I haven't looked at them in over 3 years. I do know they have plug and play adapters that will just plug right into the ECM harness. Which is nice.

[Brown_Muscle]

Fuel pressure should be around 39PSI.
Base timing is 10 degrees.
TPS is generally set using voltage, I believe it is between .5 and 1.1 volts, some people like to set it at .9, but technically anywhere in that range should work, the computer reads where the TPS is at startup and uses that as a closed position.

[Brown_Muscle]

I think I'm having a similar problem with my Mustang GT HO ECM. After the changing out coolant and throttle sensors, I'm getting a good idle now. However, I’m lucking if I get 15 mpg. I’ve been looking at a Megasquirt ECM for better engine control (http://www.diyautotune.com/catalog/m...-50-p-524.html). Maybe it will help with your problem as well as mine. A little pricey though. Has anyone tried them?

What is your setup? 15 is average, or highway? If highway you should be getting better if you have a HO swap. Like GM guy said, open the ECU, check that the capacitors are decent. Otherwise there are a plethora of reasons why you might be getting bad fuel milage

[fivelstang4]

Fuel pressure should be around 39PSI.
Base timing is 10 degrees.
TPS is generally set using voltage, I believe it is between .5 and 1.1 volts, some people like to set it at .9, but technically anywhere in that range should work, the computer reads where the TPS is at startup and uses that as a closed position.

Thanks.

I meant voltage not ohms, sorry

[His Royal Ghostliness]

I go for 0.9 to 1.0 volts at idle, the closer to 1.0 the better. Seems to work good for me, and I've done a few... Including one GT40/Expy intake swap with the Mk7 ECM that I had a hard time keeping it under the speed limit afterwards That was in a Mk7 tho, so the ECM was right at home there as far as wiring goes.

Agreed on Brown Muscle's FPR and timing numbers, 35-40 on the fuel and 10 degrees BTDC as a starting point then you may be able to work your way up to 12 or even more. IIRC that Mk7 I mentioned above runs 12 degrees now.