Hey guys. Well, I tried to do a duraspark conversion in my 1986 F150, w/ 6 cylinder, and am not getting any spark; got a timing light, with trigger taped down, pointing into cab. I got a new old-stock Motorcraft distributor (DA-1997); allegedly, these were put in 1980-1986 Duraspark i6 vehicles. I'm using all new electronics minus the wiring harness which I got at a wrecking yard (new ICM, coil, distributor cap, rotor and wires). I checked the wires and am pretty sure I got everything hooked up correctly (this is my second DSII swap and my wiring followed schematics). With ignition on, getting just less than 12 volts at coil +. With ignition on start, and motor cranking, getting just less than 9 volts at coil.

I suppose I'm curious what you guys think about 9 volts at cranking... is this a normal reading?

Anything about this you guys may help with would be greatly appreciated, and I thank you in advance.

 

Yes that is normal cause the starter is drawing down the battery voltage during crank.

Time to start ringing out the junkyard harness to make sure it has continuity though out.

Just as a reference here is the DS II wiring (See below). Since you started from scratch you could have upgraded to DS I instead of DS II

 

Thank you for the advise; I just ran out and checked continuity for all the wires. They all checked out.

My gut feeling is something in the distributor isn't right. I got a distributor, at a wrecking yard, and it was so rusted out, I went ahead and got the new pretty one off eBay. The 2 look identical, but the old one had definite "resistance" as the reluctor passed by the pickup coil (when spinning the gear by hand). The new one has a larger gap between the pickup and reluctor, and I felt barely any resistance when spinning. Perhaps, the DA-1997, made for 1980-1986 vehicles, isn't compatible with the DS II system?

Guess I'll throw the old one in and maybe see if I get spark.

Thanks, this is my project vehicle and I enjoy tinkering with it... any ideas of stuff to check are very welcomed.

 

All the Duraspark and SSI distributors are interchangeable in terms of function. Reluctor to pick up gap is 0.015" to 0.025"

 

Sounds low to me. Is your battery fully charged? I've seen either 9.5 or 10.0 as the lower limit for battery voltage under the load of the starter. Higher is better, I prefer 10.0. A voltage reading of 8.something is well below either limit and is cause for concern. That indicates a battery partially discharged and/or in poor overall condition, and/or the starter having to work too hard due to extra drag.

Does your starter cranking speed seem normal? Or is it dragging?

Can't say for sure this would kill the spark, though, but something ain't right. I'd suggest fully charging the battery and trying again. Please let us know what you find.

 

The cranking speed actually feels higher than usual. I will definitely throw a charge on battery, check the gap between pickup/reluctor and give it a shot tomorrow.

Thank you guys

 

Make sure you are getting 12v at the ignition module during run and cranking positions. This system must feed the coil and the ignition module power at the same time. This system is also grounded through that single wire going to the distributor. You may want to check to make sure that ground is good.

 

Well, I did some testing and found 9.6 volts at module when cranking (I have a charged battery and added a jumper pack). Also, when cranking, I'm getting 10.1 volts at the battery. When, in run, getting 12.3 volts.

I measured gap, between reluctor and pickup and it's about .035"... I read you can bend in pickup a bit to tighten the clearance a tad; I might try this tomorrow.

Thank you guys. Embarrassingly, I never messed with distributors much before and am learning a lot from this... thanks again.

 

How do you know you aren't getting any spark? Try holding a long screw driver 1/8" from ignition coil output while grounding the shaft. You should see a spark jump.

 

Hi Jackietreehorn,

You've helped me so much in the past, and I thank you much for this and reaching out again!

I've been working on this without a helper, so I've been using what tools I have around. I've determined "no spark" as I've setup a timing light pointed into the cab off the #1 plug wire (with trigger taped shut). When cranking, this rig hasn't even let out a single pop of fire and I'm not getting any signal off the light.

I know the gap between the reluctor/pickup is too wide at .035". This is disheartening as I bought the Motorcraft distributor as new "old-stock" off eBay. I did read that you can narrow the gap by bending the pickup slightly but am reluctant to actually do this as I dont want to break it.

The second issue is voltage. My truck still has the minimum sized battery for a 1986 and I've read that a 1979, or earlier, calls for more CCA (I'm assuming for the higher voltage Duraspark system). I tested voltage at ICM, at cranking, and getting about 9.6 volts with a jumper pack added (which is probably too low).

Finally, though all the electronics are new, I'm wondering if the ICM I ordered may not be good. Again, through my research, I've read that ICMs can be faulty from the factory (especially cheap ones... like the one I bought).

This weekend, I'm planning to try the older distributor (that has a proper reluctor/pickup gap), run a new bigger battery and see if an auto parts store can verify my ICM is good.

Last time I did a swap like this, I got all the components out of a single donor rig at the junkyard (all Motorcraft stuff). Guess I'm learning a painful lesson on this one...

Thank you all again! Any thoughts/ideas are welcome

 

Glad to help always. I would invest in a remote starter, they're only a few bucks and allow you to see what's going on under the hood while cranking. I made my own out of a jumper cable. Can't hurt to try the other distributor, although I bought one NOS from spark surplus on eBay and it was fine no problems.

 

Got 'er running, thank you guys. Ended up getting a Painless 30812 harness, wired it like they advised, bent the pickup within spec of reluctor and ran "switched" power to 16 guage white w/ green stripe wire (instead of thick red w/ green stripe wire). I honestly have no idea what actually was the problem, but am tickled pink my rig is running better than ever! Thanks again

 

I think that is probably the white/blue stripe wire. The colors are hard to make out when the wiring gets old and cooked from underhood heat.

 

You are correct, it actually is a blue stripe on the white wire. Just got back from a 300 mile trip, up in the mountains, and averaged 19 mpg! Couldn't be happier, thanks again fellas!

 

19 MPG!
What you got for a transmission and rear gears?
I was lucky to get 15 once and that was mostly high way and flat!
Dave ----