Hi folks!
This is my second post and since I cannot seem to post to my garage area yet, I'll provide some information about my truck and the puzzle I am trying to solve. First, my pickup is an old beater, salvage titled 1988 F150 with a worn out SD 302, 5 speed manual, 4x4. I traded into the truck because I wanted something I could both play in the mud/snow/woods in and also pull my little camper trailer behind it to deer camp. Last year, I found out that the engine just isn't up to the task and it has shown evidence of being pretty much worn out since then. (intermittent knocking from the crankcase occasionally and oil pressure dropping out when the engine is at idle and warmed up. I found myself needing a stronger engine and as luck would have it, came into a built 5.0 HO out of a 1989 Mustang. (engine was not original to that car).

Since it was the cheapest way to go, I have already swapped out the engines, EEC-IV's, and engine harnesses. I have taken many pictures, but unfortunately not nearly enough of the electrical systems. I'm pretty good with the mechanical stuff, but am a bit challenged where electrical systems are concerned. What I do know it that I drove the Mustang into the shop and it ran very well up to the point that I removed it. Since making the swap and hooking up the new harness, I am not getting any power to the ignition, fuel pump, or injectors. Heck, I honestly don't even know if the ECU is getting any power for sure or not....

I am getting the engine warning light and the gauges seem to be working, but I've also noticed that when I disconnect or reconnect the battery that there is no arc or sparks at all when the switch is off, leading me to think that maybe the computer is not being energized at all.

The original truck EEC-IV was a 8QA and has been swapped for the H.O's A9L. Since the Mustang harness and computer was originally in the passenger kick panel area under the dash, switching sides and routing the harness on the driver's side of the F150 has been a bit of a challenge. I know I honestly can't expect any of you to fix my wiring for me, but if you could offer any advice or insight that might steer me towards successful completion of this engine swap issue, I would be mighty relieved, cause this thing is kicking my butt. Sure I could take it to a professional mechanic, but I'd like to learn and solve this with my own two hands, if not by my own knowledge. I wish I could post up some pictures, but haven't met the criteria as a new forum member yet....



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Welcome in! Lots of good knowledge here, I think someone will be able to help you.

For posting pics, using a site like Photobucket or similar seems to work well, and you don't have to wait to have enough posts to add photos.

I'm far from a genius with wiring and swaps like yours, but one thing I've picked up on through reading over the years is to use the harness that came with the truck. Also, if your check engine light is coming on, the PCM has power.

 

Thanks for the welcome Bob Gervais! I've got a photobucket account already so I can just upload some of the photos to it and see if I can link them to my posts somehow.

 

Welcome , and best of luck ! I hope you get it sorted soon !

 

Thank you JWC 3! I know that I'm eventually going to get this thing straightened out and I am sooooo looking forward to hearing the rumble of that sweet little small block! The anticipation is making this whole issue more aggravating because it's probably something small that I just don't yet know about.

 

Just how "built" is this engine?

That is your problem if you didn't change ALL the wiring between the engine and EEC, the chassis portion of the wiring from the truck is not campatible with the SEFI MAF Mustang EFI system.

If you have installed all of the Mustang wiring harness in the truck then start by pulling the codes to see what's flagged, if you get a whole pile of codes then you have made serious wiring mistakes. If the old truck wiring harness is still intact it may be easier to convert it to MAF using portions of the Mustang harness, you would need to remove the injector and MAF sub portions from the Mustang harness complete with the EEC connector pins attached to the wires, and then open up the truck EEC connector, move some wires around and insert the injector and MAF portions from the Mustang harness. This gets you around having to trace and reattach the fuel pump and EEC relays, all the basic engine sensors, distributor, and the various power and ground connections. I have a nice spreadsheet showing the differences in the truck and Mustang EEC pinouts if it would help.

 

Hi Conanski, I don't have all the specs on the engine, but I was told that is was bored .030" over to a 306 CID, Double roller timing chain, an aftermarket camshaft (nothing too radical), GT 40P heads-ported and polished. Cobra intake manifold and intake. It belonged to my eldest son, but he wrecked the Mustang it was in and decided it was going to cost too much to repair the car. He bought it from the guy who built the engine and had installed it. I did only just change the engine harness like you mentioned. No wonder I'm having such a hard time!
I guess I've opened up a hornet's nest by only switching out the engine harnesses! I still have the one for the pickup, but did cut off a portion. I think I can put it all back like it was though. I'd certainly like to see the spreadsheet you mentioned. I knew something was wrong! Haha! Any information you have is most certainly welcome and appreciated. Thanks!

 

Yeah.. there is no way it could work that way, the wires for the MAF meter and sequential injection don't exist at all in the truck harness and a handfull of sensors and actuators are located on different pins in the EEC connector.

If you can restore the truck harness and make sure it's working on the HO motor you'll have better luck converting it to MAF afterwords. And just so you understand what I'm suggesting, I mean put the truck wiring all back on and hook it up to the motor, put the truck computer back in, and with the plug wires routed for the HO firing order that motor should start up and run. Once you got that then adding the MAF stuff is easy, see the link below for info about opening up the EEC connector to move and add wires, and the spreadsheet for where all those wires need to go.

Fuel Injection Technical Library » EEC Connector

 

Note if the red wire at the injectors do not have power than the Computer will not have power on the main power pins (V-PWR pins #37 & 57).
Maybe you will have keep live power on pin #1 only.

 

Conanski, All I can say is WOW! This should put me back on the right track. I wish I'd have had your spreadsheet before I dove into the wiring like I have. I forgot that I'd already dismantled the pickup harness pins from the connecter like an ignorant fool. Now I've got a choice of either trying to repin the old harness or go searching for another one to save me the trouble of sorting through that one. I may just trash the old one and go looking for a fresh harness to victimize! Haha! I waded into this whole thing thinking it'd be an easy swap, and it was, right up to the point of having to deal with the electrics. But on a positive note, I have learned some things from this experience and maybe it'll come in handy down the road if I have an electrical issue crop up. I'll try and post some pictures of what I've been doing. The engine isn't too pretty looking and dressed up, but it made my son's old Mustang move pretty fast!

SD302 being retired;





Mustang 302;

 

Well guys sorry I haven't posted anything in a while. I have been fighting the good fight and trying to get my engine to run. I, being the hardheaded type, still felt like using the Mustang engine harness would be a little easier to modify, being that it'd save me the hassle of rewiring the injector circuitry. However, I opened the door to some other difficulties in return and have been trying to sort them out. I have a weird feedback situation where the switch will crank the engine, but it will not shut it off. Gotta fix that asap! Also, I have no signal to the tachometer yet either. However, after wiring in the fuel pump circuit, I finally got it to run and man, am I pleased! I have a little more to do, but it's looking like I'm getting there! I know it is a rough looking truck and engine, but I sure am proud to call it mine.