Hi I am new to this site but ill tell ya a lil bout my truck. It began as a 95 F-150 2wd automatic with 300 straight six, E40D,. I have done a few drivetrain mods an now it is a 3/4 2wd with a granny low 4 speed an 3/4 springs an axles from a 94 F250. I ran the 4.9 for years an had a 88 bronco with a 5.0 from a few years back. I have removed the 4.9 an installed the 5.0. I had to buy the wire harness for the engine out of a 94 bronco an distributor to transfer the ignition module to the fender which wasnt done in the bronco. Everything bolted up with ease. I got the timing set correctly. It cranks but runs rough. Like not on all cylinders. Do I need the computer out of my bronco work or will it run it because they are both speed density computers, an if so then is my problem in the ignition module cause I am using the 4.9 computer an ig. module. I see that the 88 computer plugs are identical but am not sure. Any help would be appreciated.
Ahh.. yeah... you need a 5.0 computer, the 4.9 unit won't work because it's a 6 cylinder computer.. and the 5.0 has 8 cylinders.
Also complicating matters... is your '94 harness an SD or MAF harness? That matters because SD uses batch fired injectors and MAF uses sequential, and that means the SD system has 3 wires in the injector harness and MAF has 9, so you also need the matching 5.0 SD or MAF computer for that harness.
I honestly didnt think it mattered on the number of cylinder on the fact that the timing is run off the pickup module in the distributor. Same as the 6 cylinder. If it recieves 2 more cylinders than it will give signal to coil to fire. The sensors bein mainly the same with the exception of the map sensor. But I have the 5.0 computer. I will change it. As far as the harness goes the the maf sensor on those trucks is in a separate harness near the electrical box not in that part of the harness, the injectors having more plugs wasnt any different on the main harness where it connects at the fender.
I honestly didnt think it mattered on the number of cylinder on the fact that the timing is run off the pickup module in the distributor. .
Yes but the computer is only expecting 6 pulses and the distributor is sending 8. It can't work, computers are really dumb that way.
Originally Posted by SparkyShaft
As far as the harness goes the the maf sensor on those trucks is in a separate harness near the electrical box not in that part of the harness, the injectors having more plugs wasnt any different on the main harness where it connects at the fender.
So does that mean the harness you have is a MAF version? If it is then you need the matching computer and MAF meter, otherwise it will never run. There are a lot of wires that get moved to different pins or used for something else when switching from SD to MAF.
Yes the Harness was from a MAF truck. I see that your supposed to remove the MAP sensor when adding in the mass air sensor. does that mean those wires from the map can be used to wire in the maf. I will go back an pull the computer an sensor from the 94. I know ford is notorious for havin the plugs there for other applications. If the map doesnt swap with the maf. Is there a factory plug already accessable to add in the maf.
Yes the Harness was from a MAF truck. I see that your supposed to remove the MAP sensor when adding in the mass air sensor. .
On these trucks apparently yes, the MAP sensor was dropped when they were converted to MAF.. but the MAF uses different pins at the computer than the MAP sensor so you cannot unplug one and connect the other, you need the correct MAF harness portion from the donor.
Now I have to tell you about another problem you're going to have. The '88 5.0 uses a different firing order than the computer you will be using, and since the injectors are fired sequentially this means it won't idle worth a damn unless you move some pins around. Assuming the 5.0 is all original it will have a 15426378 firing order and your MAF computer is setup for a 13726548 firing order, so what you have to do is swap the wires for injectors 5&3 and 4&7. The computer connector comes apart so this isn't a hugh deal, see here Ford Fuel Injection EEC Connector for details about that.
Ok thanx for the heads up on the injector. Another question is, on the earlier HO 302 '82 they say they used a 351 Marine cam to make the first HO302's Can I put a 351 cam outta a Marine in my 302, change firing order an it work. My dad has a 351 Marine engine in his 80' Bronco outta a shrimp boat. He changed out his cam for an edelbrock. Will his cam work. I see the cam journals are different sizes through the years but are the same for certain years. Would that solve my injector firing problem as well with comp...etc.....
Its weird though cause to look at the pin connectors an a diagram of the computer pins layout. The only difference I see is the MAF an the MAP an like you said the injectors have there own wires as opposed to the speed density feeding the banks 4 at a time. If you compare this to a straight six computer the speed density is same all way through. Anyways when I crank my truck by the pin layout it woulda only been getting fuel through 2 injectors an if thats true than shouldnt I be able to wire the 4 injectors together at the engine an loop the other four together to produce the bank sequence for the injectors? But the same 4 that the speed density computer says it fires at once. 1,4,5,8 and 2,3,6,7
HOORAY!!!!! Ok I got it working! It purrrrrred like a kitten after I rewired the injectors. If your kitten had 3" headers on it that is. lol I simply took the injector harness from my 88 donor, ohm the wires out with my meter,determing #1 Bank an #2 Bank, Found the #1 an number #2 injector, tied in the common an then the #1 injector to the #1 Bank an #2 to the #2 Bank. Reason for #1 an #2 injector was that the pins that go to the computer run to #1 for #1 Bank an #2 for that bank, And in my old harness it was already wired that way. I am still going to change out the computer but it is running on the 4.9L Computer. Sounds like it should. I only worry bout advance in my timing, are those distributor mechanical advance only? If so I should be fine! Thanks for your help on my injectors man I wouldnt have figured it out without ya. I hats off to you my friend, Any questions or if I can return the favor lemme know.
I'm bringing this post back in hopes I could get some help. I am in the process of doing a similar swap. I have an 88 bronco with a 300 in it and I'm swapping in a 302 out of a 93 bronco. I have both trucks complete so I should have all the parts needed. What I need help with is the harness. Both vehicles are map systems with that being said can I use the harness out of the 88 with the 93 302? I have the 302 harness but I really don't want to have to pull that harness if I don't have to. I'm sure I'll have to swap the injector harness but will I need to re-pin the ECU at all? Any help would be greatly appreciated.
Ok looking over the pinouts everything looks good except for one pin, on the 93 5.0 pin #8 is "fuel pump monitor" and that is non existant on the 88 4.9 pinout. Should I swap pumps and run a wire from that pin to wherever the fuel pump monitor should go? I'm assuming the fuel pump but again I'm not to sure. A little info about me. I'm 23 so this truck was made when I was 1 so I really don't know much about them. Although I am an ase and Toyota trained master tech. If this was a 4 runner or something I could tell you about anything you want to know. I need some help from you ford guys!
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