engine harness question
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Mountain Pass
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engine harness question
is there any difference in the engine wiring harness on a 1993 f150 302 vs 1994 f150 302 they plug up the same i just wanted to make sure there isn't any reason they wouldn't work properly
FTE Legend
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From: Ottawa, Ontario
Yes there is a possibility they are significantly different so you want to avoid mixing harnesses if at all possible. If you are doing a motor swap do not use any wiring currently attached to the donor motor, remove it all and attach the harness currently in your truck.
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Mountain Pass
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ok so what would the difference be on those years they are both xlt 2wd 302 automatics with pretty much exact same options. does anybody know of any reason truck wouldn't run with this harness. the engines appear identical as far as the electrical and everything
FTE Legend
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From: Ottawa, Ontario
The '94 could have been MAF and if so the injector harness would have 9 wires instead of the 3 used for SD. The motors themselves are identical except for the camshaft which means the firing order is different so if the '94 is the one you will be using be sure to route the plug wires for the HO firing order(13726548). The won't have any effect on the SD control system since it fires the injectors in batches and works qually well with both firing orders, but this is the reason why you must use the SD engine wiring harness. Both motors use the same sensors in the same locations and the complete engine harness comes off in 1 piece once the upper intake has been removed so it's not much work to avoid potential problems. You could take a chance on it and if the motor doesn't run very well when you fire it you know the harness is the problem, but I'd change it ahead of time if it were me.
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Mountain Pass
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the truck i am working on is a 93 the engine is a 94 i'm using the 94 harness the truck isn't getting fuel through the injectors for some reason.it cranks right up if you spray starting fluid in it.I put one post on here but can't get any response from it. truck has new fuel pump,regulator, and filter i put the other distributor in it and tried that thinking it could be the pickup coil, but that didn't change anything either.also tried the 94 computer.Iwired the truck for the h.o. firing order.Does the 93 have the standard 302 firing order 15426378 just wondering
FTE Legend
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From: Ottawa, Ontario
I bet if you could check you'll find injectors #1 and #2 are passing fuel, those are the only two that are connected to the EEC through the '94 harness. And that means the '94 wiring harness is your probem, change it back to the '93 and all your troubles will go away.
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Mountain Pass
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i think i'll try changing the harnesses then i plan to use the other engine in a 94 so if that's the case i may have the same problem there
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Mountain Pass
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FTE Legend
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From: Ottawa, Ontario
Again it depends if the other truck has MAF or not, if it doesn't then you won't have any problems as long as you don't try to use any wiring besides what is currently in the truck. If it does have MAF then you will have to make a few small modifications to the injector wiring to match it with the old firing older of the '93 motor, I can detail what's needed there too if you like.
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Mountain Pass
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ok i changed the engine wiring harness and the truck runs.now it runs good down the road but at idle it's loping really bad idling up and down but when you give it gas it clears up pretty good.my brother in law has a 1990 f150 351 that's doing the same thing too they also start smoking like they aren't getting the proper mixture or something truck has new regulator any help appreciated
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Mountain Pass
Joined: Jan 2008
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ok i changed the engine wiring harness and the truck runs.now it runs good down the road but at idle it's loping really bad idling up and down but when you give it gas it clears up pretty good.my brother in law has a 1990 f150 351 that's doing the same thing too they also start smoking like they aren't getting the proper mixture or something truck has new regulator any help appreciated
FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
OK do you have everything hooked up the way it should be for a '93 except with the plug wires routed for the 13726548 firing order? You're using the '93 computer too right? If all that checks out pull the codes to see if anything is flagged.