Edist msd dis 4 problems (long)

[Modman]

Wondering if any of you can help me out. I have a 88 mustang with a 4.6 dohc, xfi and cop ignition. I had it running fine straight off the edist for about 200 miles. Then coming along in traffic it started to act like the timing was slow, and the edist burned the board. So I talked to fast, they said that i toss in anther edist, put a dis 4 inline, rewire for waste spark and go. I have 1+6, 3+5, 4+7, 2+8 tied together. And going by the way the car was running before, i wired 2+8 to output A on the dist, then 1+6 to B, 4+7 to C, and 3+5 to D. The dip switches on the edist are set as 1 off 2 off 3 on 4 on 5 n/a 6 on 7 on 8 on. THen the wires from outputs a-d are wired to the msd dis 4 inputs. The only thing i didnt follow in the scheme of things was i wired the input 1 of the msd to cylinders 1+6, and went down the line. From what i read it really shouldnt of made a difference. The msd has the switch for wastespark set to on. I can do the test in msds instructions, where you ground an input and it sparks the output. so i unhook the edist, and ground the wires at the connector and it sparks the correct cylinders. Hook up the edist, the red led is on, the yellow is flashing and the green led is on. But the msd led flashes quick then starts to flash 1 per second like its not getting signal. Then it will start to flash quickly. Hook some fuel up to it, and it cranks, kind of fires, it will keep cranking, then backfire. Pull the plugs and 1+6 and 3+5 are fouled black, and the rest are clean and wet. New plugs went in, raised the crank to run rpm, it acts the same, but the only plugs fouled are 2+8. Will the key on, the msd will flash 1 per second. What is the signal coming out of the edist? Can i use a meter of some sort to test to see if the edist is working? IM at a loss, and the guy at fast i was talkin to will not return my calls. Any help is appreciated. Thanks

 

[Modman]

Well acutally running the power and ground wires to the battery for the dis 4 helped out. It runs, but only on 4 cylinders. Is there a way to test the outputs of the edist?

 

[Craig Smith]

Try reversing the polarity of the cam sensor input to the eDist. The problem is that the cam input is seeing more than one pulse per rotation of the firing order and resetting the cylinder counter back to the first cylinder. IIRC the most common cause of this with the old eDist setups was cam sensor polarity.

 

[Modman]

Well i got it running again. Tried a new dis 4, no help same problem. traced the wires some more, and didnt find anything new. INstalled the new flash and bingo the car fired right up. I dont really know why this fixed it, but it did.