Hello all,

New guy here. I recently acquired a 1986 F-150 and performed the duraspark conversion today. I actually had the engine running after dropping the distributor and rotor into roughly the same position as the original. I assume this was with engine timing at 10 degree BTDC because thats what computer would have defaulted to due to the hackjob the PO did with the emissions.

However, I noticed that the distributor was not fully seated as there was about a 1/4 inch gap between the engine block and the distributor neck base. I tried to work it down to no avail by twisting the distributor housing. It seems like the distributor will only seat with the rotor turned a certain way.

Then, I had the brilliant idea to pick up the distributor and rotate the gear/rotor to get it seated. I eventually got it to seat but now the engine will not start. I have tried to set the engine timing to 0 degrees TDC by rotating the crank by hand and lining up the marks. I then attempted to set the rotor to the number 1 plug on the distributor, but no dice.

I do not understand how to line the rotor to the number 1 mark on the cap because the cap's number 1 position is relative to the distributor housing, meaning that the housing must be set first. It is like trying to hit a moving target. When the distributor gear is set, the rotor is immobile but the base is free to move.

I do not have a timing light--I am a college student away from home so my tool access is limited. How can I get this distributor and rotor properly oriented t so that my truck will start? Thanks in advance. (no pun intended)

 

As you found the rotor/shaft is located by the gear & oil pump shaft so where it falls it falls.
With that said you have to turn the dist. body to get the non-moving the rotor to line up with #1 on the cap.
Try have the rotor point a little before #1 on the cap not right at it.


Now are you sure it is getting spark? That would be another reason it will not start.
Oh you need a timing light to set timing. I hear you can use a vacuum gauge but have never used it to set timing.
Dave ----

 

Almost forgot welcome to the forum.
Dave ----

 

The reason it's not going in all the way is the oil pump driveshaft. You can get the gears lined up, but as it spirals down it has to engage the oil pump drive.

Not sure what you are working on, but I know the 302 and the 351w have a hex shaft on the oil pump. If I remember correctly the 302 is 1/4 and the 351w is 5/16". Or is it 5/16 and 3/8? Can't remember. But what you can do is get the engine and the dist setup, drop it in, if it won't go that last 1/4" pull it out, get some 1/4" extensions and the proper size socket. Get some tape and tape all the pieces together, carefully put it down in the hole and try to get it on the oil pump shaft. Once you get it, turn it just a little bit.

It's hit or miss, but if you turn it just a bit, you can eventually get the dist to drop in where you want it to.

 

Okay,

It is a 4.9 engine. I also forgot to mention that oil pump driveshaft came out stuck to the original distributor. I have it inserted into the new distributor. Should I insert the shaft into the oil pump instead?

 

Got it running! albeit poorly.This was accomplished by rotating the crank clockwise and setting the mark to 0 degree mark on the damper. I don't have a socket to remove the spark plug so I had to go by trial and error. The carb backfired and the idle is so choppy the distributor is shaking....

The rig is a 4.9 with a rebuilt Carter YF, NOS Mototcraft distributor and a genuine duraspark module from a junkyard. I am running the original TFI coil so hopefully that will not fry the module.

1. Will the TFI coil fry the durapsark module? I cannot find definitive answer based on other forums.

2. Where do I take it from here?

I appreciate your sage advice.

Best,

Mick

 

Hi Mick,

Welcome to the forum. Lots of intelligent, helpful people here. I'm here, too.

I can't really help with your ignition questions but just have to say I love your username.

 

Do some investigation on that coil, I don't think it's compatible with the DS2 system.

Still sounds like you need a timing light, too.

 

The duraspark IGN module will fail at some point due to the extra current draw caused by using the square TFI coil.
For a more exact answer I need more info...
Did you use a DS2 IGN harness of a older truck?
What is you voltage at the coil positive connector, key ON not running and at idle?

Jim

 

Till you can get a timing light on it have the dist. loose enough that you can turn it by hand but will not move when running.


Have the motor running at idle and up to temp, vacuum disconnected and plugged, turn the dist. till the motor runs smooth.
You may go pass smooth or turn it in the wrong direction so turn it back a little or other direction till running smooth. Tighten the holding bolt hook up vacuum line to ported port on carb.


Take the truck for a test drive. You should not get any pinging if so turn the dist. a little in the opposite direction the advance pulls and test drive again.
Keep doing this till no more pinging.


What carb are you running? Is it the computer controlled one if so you need to change it out for a non-computer controlled one to have this run right.


What heat range plugs you running? Too hot can also make it ping.
Dave ----

 

Hi Jim,

The voltage on the TFI coil's positive terminal relative to ground is 12.68 VDC when the engine off and the key in "ON" position. The voltage while at idle is 10.46 VDC.

I grabbed the harness off of a late 70's or early 80's Ford truck. The harness mated perfectly with truck. I cut off the stock coil horseshoe connector because I wanted to save money and use the original coil. From what I have read, there is no consensus on the compatibility of the TFI coil with a duraspark ignition.

Shouldn't that integral resistor wire drop voltage and prevent the module from frying?--If not I will bite the bullet and acquire a traditional can coil.


Dave-- I am running standard Motorcraft copper plugs--freshly installed. Carburetor is an early 1970's era Carter YF. When I get my hands on a timing light I shall adjust it properly. It seems to run OK other than idling poorly in Park or Neutral. Idles fine in Drive.

Thank you

 

Here are some images for those interested:

Mick_Bijak's Recent Uploads | Photobucket

 

The resistor wire is usually bypassed, which is why you are getting 12.68 VDC.

The 10.46 VDC at idle is lower because it is a square wave and your meter is trying to average it down.

The square TFI coil is about 1/2 (.7 ohms) of the round DS2 coil (1.3 ohms)

So your current set up is about 4 times normal current flow. The module will fail.

If you want to save money, just buy a GM 4 pin module like this one

GM Hei 4 Pin Ignition Module 1974 1988 Chevy Pontiac Olds Buick LX301 D1906HT | eBay

and hook it up like this...

Better Dirt Cheap Electronic Ignition

That is what I did.

Jim

 

Okay,

I happen to have a high-wattage power resistor left over from my 67 Valiant. Assuming it is about 1 ohm couldn't I wire it in series with one of the coil wires ?

 

You could just add it before the coil and see how much it drops the voltage.
Cant hurt to try it,