I have an E150 1984 with a 4.9 l (300 cu.i) L6. The problem is this; it appears to have an advance (timing issue). The vehicle's distributor (carburated)has it's spark control unit ( a 3"-square box) on the side of it where, along with the cable harness, is a connector that disconnects the computer (located under the dash on the passenger side. This point is important). I've been told to disconnect this plug and time the vehicle at an idle, then plug this connector together and the computer SHOULD take over. Well, what happens is that the timing is thrown out so far that there is very little power and it pings like crazy. So what I've done is RE-TIMED it after connecting the computer. The timing advances somewhat but only if I race the engine with no load. Under load, it DOES NOT advance. For what I and some other mechanics can tell, it must be the computer as I've tried replacing the MAP (manifold atmospheric sensor), a device that affects the dwell setting sent from the computer to the distributor, I'm thinking by way of this plug that I mentioned before.
Sooooo, if it is the computer (remember I said it was located under the dash on the passenger side?), here is the number:
E4EF-12A650-Y1A.

So far, my searches to many, many autowreckers, online and off have come up with nothing. The dealer wants $325.00 Cdn.

As well (insert stupid question alert here?), would this unit NOT be fused from the fusebox located under the dash on the driver's side?

Any help would muchly be appreciated!
Jeff

 

Well Jeff, all I can say is: "They make trucks with computers in them"
Seriously, I am not an expert on how those computer controlled vehicles work. Unless you are referring to another sparky on here, if so I apoligize for answering.
I am sure there is a fuse for the EEC, and I would think it would be in the main fuse box. Of course it could also be under the hood, I think those "new fangled" vehicles have some fuses and relays under there. I have a manual for the computer equiped trucks, I mean had one it is kind of gone on temporary/permanent loan to a friend of mine as I have never personaly owned a vehicle built after 1983.
When it is pinging the timing is way too advanced, which I am sure you already know. So maybe you could set it up and then turn the distributor back a little at a time til it doesnt ping. That is how I setup most of the "old" vehicles I have.
Sorry I am of no help.

Sparky

 

I had an 1985 4.9 that had much the same problem. First question is does the EEC system pass the self test? Mine had no power going to the computer due to some southern Ontario corrosion in the wiring. I still wasn't happy with the way the truck ran so I converted it to Duraspark 2 from a 78. It ran better, and allowed me to tune the advance curve to what I wanted. I think I still have the computer from the 85 around in the garage somewhere, but if you don't have any emissions testing I'd convert to duraspark.

 

Hey, I got the answer for you.........get you a real truck. Like a 67 F100 with a 390 in it, won't have to worry about a computer again. :7

 

I am going to ask a few questions here and then maybe I can help.
You have a early version of EEC-IV. The spark control you refer to I believe is the ignition module. There should be a flat plug inserted into it a few inches from this plug should be a removable plug in the harness. This is called the SPOUT connector. It is removed to set base timing on the distributor. Now understand this no matter where you set base timing, if the computer thinks that timing needs to be advanced or retarted it will try to achive it. Its really frustrating too. You cant just leave the plug out or else you do get timing advance under load.
I have seen this happen before, Its been along time ago so forgive me if i dont exactly remember what I did to fix it. But for some reason replacing the pickup in the distributor rings a bell.
Here is what I would do. Get yourself a timing light with a advance wheel. Hook it up and start the engine with the SPOUT connector out. See what your timing is. Then re-install the connector and check it again. This is what the computer thinks timing should be at idle(I almost forgot a very important thing. The engine needs to be up to operating temp.) Ok next thing rev the engine up to about 2000 rpm and check the timing again. It shouldnt be more than a total advance of timing of 35 degrees or so. If its around this mark the computer isnt overadvancing the timing. I am sorry if I am missing on any of this but I havent worked on this variety much you see they were only around for a little while.
As for a fuse for the computer...there is a fusable link at the starter solenoid. Make sure its good, I once worked on a truck that the owner had replaced the starter solenoid, when he hooked the wires back up he put the wire for the computer on the starter side of the solenoid, needless to say the computer was only powered when the engine was being started....good luck

 

 

[updated:LAST EDITED ON 04-Jan-02 AT 12:07 PM (EST)]The spout connector on this one could be the old inline style, my 85 had one of those. One real quick way to see if the advance is working is to disconnect the spout as the engine is running and see if the rpm drops as the advance is removed. I know its not a 100% fool proof test, but easy to do.