Mind boggled

[stranger_5oh]

I'm doing a v8 swap on a 91 ranger. I have a 91 mustang harness and a9l ecu. The biggest problem I ran I to is that the conversion manual says it should have 1 brown connector to splice from under the hood but I have 2 connectors there which are black and gray. I also have EVTSM'S for both the ranger and mustang which helped with the wiring.

The newest issue I have run into is that while the key is in the on position and I turn the distributor to a certain spot the fuel pump relay kicks on and runs the fuel pump. When I go to start the truck I have to hold it at wide open throttle before it will start and it will die after a few minutes of running.

I've double and triple checked the wiring which is most likely going to be the culprit. If anyone who has done a swap with a harness with the gray and black plugs instead of the single brown plug the help would be appreciated.

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[jeepfreek]

Do a search on pirate 4x4 , they have a write up for the same problem and it shows which pins you need to use. I'm working on this same problem myself, just haven't had time to complete it. Hopefully this weekend I will work on it , and if I figure anything out I will let you know.

 

[stranger_5oh]

Do a search on pirate 4x4 , they have a write up for the same problem and it shows which pins you need to use. I'm working on this same problem myself, just haven't had time to complete it. Hopefully this weekend I will work on it , and if I figure anything out I will let you know.

Thanks man I'll see what I dig up... appreciate the info

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[Elutheros]

I don't know if this will help, but here's how the connections on the black and gray plugs ended up on mine. I can hardly remember what I did and I used a 1989 Marquis harness, so there may be differences. These are diagrams of the male and female ends of the plugs and where they are located now in my truck.
I'll try to answer any questions--but my memory is blurry on all this stuff I did a year ago.

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[bobbywalter]

I'm doing a v8 swap on a 91 ranger. I have a 91 mustang harness and a9l ecu. The biggest problem I ran I to is that the conversion manual says it should have 1 brown connector to splice from under the hood but I have 2 connectors there which are black and gray. I also have EVTSM'S for both the ranger and mustang which helped with the wiring.

The newest issue I have run into is that while the key is in the on position and I turn the distributor to a certain spot the fuel pump relay kicks on and runs the fuel pump. When I go to start the truck I have to hold it at wide open throttle before it will start and it will die after a few minutes of running.

I've double and triple checked the wiring which is most likely going to be the culprit. If anyone who has done a swap with a harness with the gray and black plugs instead of the single brown plug the help would be appreciated.

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the problem with a swap manual....it only applies to the harness its talking about. the problem with ford wiring harnesses... they are not always the way they are supposed to be right from the factory. if you work with them long enough you will learn some crazy stuff happens and sometimes they make due with what they have. the connectors will usually have the correct color for a foot or so and then spliced into a grey wire or whatever for a ways and spliced back into the correct color wire....i have seen these splices fail....along with fuse link wire to feed the o2 sensor heaters....so, ohming out and pinning the harness is the best way to go every time ime. then compare that to the known charts.


the distributor turning on the pump is normal when the pcm has power. it thinks the engine is cranking and grounds the relay. when the engine stalls the pump shuts off....its a safety feature like the rollover switch.

the run for a few minutes and stall you are experiencing can be several things. having the o2 sensors wrong among idle values ect from when it comes out of its fixed value start up cycle are typical mistakes among wrong air meters and ignition firing/injector orders. sometimes guys think they have a mustang harness and its a type of crown vic harness... many variables there. or they are simply running a mass air computer with a speed density harness or situations similar to such.

there are a few variations of the stang harness, the factory rpo and dealer add on options can vary sections of harness...i have noticed the dealer air verse factory air harnesses are a bit different in the connectors you refer to along with the wac and eec relay type and size after 89. the o2 harness is different as well in some cases with a different loop for key power..



i assume you have the tps set correctly? .8-.9 volt is the general way this is done. sometimes this is why throttle is needed to start. the air meter can be damaged etc and i assume its a maf setup being a 91. so test it and look at what its reporting with your ohm meter and be sure your fuel pressure is correct as well. i use a gauge i can watch from the seat or hook one up permanently in the car so i know what its doing at all times. a simple 30-40 dollar electric oil pressure gauge in the fuel feed side is very valuable in my experience for relative reference.