1986 f150 with 300 inline 6,

So I decided to de-computer my engine and go with a point style distributor. Was running good before the swap but after it barley goes down the road. Its missing and sputtering horribly under load. It will idle with a slight sputter but its not what I was expecting. The distributor is new reman from the green giant along with cap rotor wires and plugs. But it is the original coil that was working just fine.

So far I have horsed around with the timing and tried disconnecting the vac advance but not matter what I play with it still has the same trouble. If I advance or retard the timing it makes it run worse.

I'm pretty good under the hood but this one has me at a loss. Any ideas?

 

Point-type ignitions usually run at around 9V, by having a resistor of some sort in the power lead. The TFI coil needs 12V to function correctly.
12V to points will tend to burn them up quickly, and only 9V running to a TFI coil will cause a weak spark. I don't know if you wired up the resistor or not, but I'd bet your issue is related to this incompatible voltage.
Or, it could be as simple as not having the points gapped correctly, a missing ground strap inside the dist, or even a poor quality condensor.

 

My original account was not working for a bit there but they fixed it.

I'll be posting under ghostshark from now on.

Awesome info there I am going to the big green to get a coil and ballast resistor. Guess I should have thought of that one in the first place /palmface. Will update soon as i get it done. only like 30$ more for the parts.

 

Points were wired up with a 12V source during cranking only, to assist with hot starting.

Running "12V" to the points/coil is actually more like 14.5V when the engine is running with a good charging system. Close to double the "design" voltage for points.......

 

Re gap the spark plugs, smaller gap, to match a older truck with point IGN system.

The points IGN system is low energy output and might not be able to jump the current plug gap.

Measure the voltage, at Idle, at the coil positive.
Jim

 

I can't believe I forgot to mention this. Pull the plugs, and close the gap a bit. Points typically run about a .035 plug gap, while electronic ignition systems run .045-.060. Too much gap makes it very hard for the plugs to fire, weak plug fire, poor running engine.

I'm old-ish, so my memory gets a bit slow. But it usually works.....
As I like to say, I've got a photograghic memory, but most the film is rather old and out-of focus.........

EDIT: I see Jim beat me to it. Told ya my memory can be a bit slow, just like my typing........

 

Also, the coil wire is different between the two coil styles, square coil - round coil.

Most spark plug wire sets will have 2 coil wires because of this to cover more engine years.

Jim

 

Well that didn't work.

so I went and got a coil and ballast resistor and tested but the output voltage of the ballast resistor is only showing 3v.

Thanks to bwd not providing ANY info on thier parts now I need a 2nd trip.

BWD RU17 - Resistor | O'Reilly Auto Parts

Thats the one i got. the RU17.

Does anyone have a part number for a proper ballast resistor I can use?

 

What if I just upgraded to the accel super stock that does not need an external resistor?

like this one? ACCEL Super Stock 8140C - Ignition Coil | O'Reilly Auto Parts

And its chrome so thats a bonus.

 

The weakest link is currently the points as they will burn up.. they were meant to run on lower voltage.

You current stock square coil is 12-14.5 volt coil, but about .7 ohm primary resistance. A DS2 is about 1.3 ohms.

The ballast resistor should match the round coil primary resistance, ~ 1.3 or so.

Equal resistance means an even split in the applied voltage.

For now just put it back the way it was, after gaping the plugs. Worst case is burning -pitting on the points in the short term.

Do you have a voltmeter?

Jim

 

Can you return the point Dist and get a DS2 Dist?
A lot better to go with a high energy electronic IGN system.

 

I would need a part number or year make model that they came in to try that.

Yes I do have a volt meter if that helps. I tested the volts coming off the ballast resistor and it showed like 3-3.5 thats why no fire on the new round coil.

Also to clarify the distributor I bought was for a 76 300 I6, it only has one wire coming off of it to connect to the negative side of the coil. http://www.oreillyauto.com/site/c/de...rd=distributor

 

DS2 Dist off 80-84 , 4.9, single vacuum advance.

Cap and rotor are different.

 

Well the end goal on this one was to have a single hot wire and no computer.

If at all possible I would rather try to "fix" the point system for now.

I did look up the parts for the DS2 system and all in all its more expensive and complicated. What are the major benefits of that for this low end torque beast?

I see in your vehicle list you say ds2 with gm 4pin no computer? hows that work?

 

GM 4 pin module is easy, works well and is about $14.
Just need a DS2 DIst.
Use the stock square coil and wiring to the coil.

Long read here.
Dirt cheap Ignition

http://www.ebay.com/itm/GM-HEI-4-Pin-Performance-Ignition-Module-1974-1988-/261468628020?pt=Motors_Car_Truck_Parts_Accessories&hash=item3ce0bea434