Ugh! After having a Holley 600 installed on my 73 302 per my mechanics recommendation, it runs really terribly at just above an idle when starting off or mainaining a low speed. If I give it the gas it really moves nicely. My mechanic says he thinks it has a vacuum leak. Something about the Edelbrock intake that was on it before he put the Holley on. I've been hoping it was the ignition so I replaced the plugs, wires, rotor cap and rotor button. Didn't really run much better. Here's the thing, the old rotor button and cap were burned on the tips. After driving it for about 100 miles on the interstate I noticed that the new button was burnt and slightly melted near the edge! Also, I pulled the 7 and 8 cylinder wires off of the distributor cap while it was running and couldn't see that there was any spark but the others checked out with a nice arcing spark. Did my doing this cause the distributor parts to heat up? Did the .40 - .44 Bosch plugs that I installed (I think my truck is supposed to have a .35 gap) have anything to do with it? Thanks for any help y'all may be able to provide.

Trent

 

Sorry... those gaps are of course hundredths not tenths.

 

What ignition are you using Duraspark II ?
or aftermarket Hi-NRG ignition ?

Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

Not really sure. Stock? Round black thing (coil?) and points in the distributor.

 

Okay.

What is the point Gap or Dwell?

How did the plugs get overgapped so much,Intentionally ??

Re-gap them to spec or .002 over and drive it somemore,see what happens.



Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

[updated:LAST EDITED ON 27-Feb-02 AT 10:52 PM (EST)]What happened?

 

Well, I'm not sure what happened... I haven't measured the point gap. It had .044 plugs in it when I got it and it ran badly in the low range. I got new plugs, gapped them to .035 myself (because the heads have the smaller plug thread size which you can appearantly only buy .044 plugs for) and it ran the same so I had the new carb put on, changed all the wires, distributor cap, rotor button thing, and plugs (back to the .044) and it runs the same. Except now I'm noticing that the rotor button is getting fried on the tip. I'm just wondering if this is a result of what I've done with the plugs or whether it is a symptom of the larger problem of why my truck chokes and stumbles down the road at 1/4 throttle. Thanks!

 

Was the carb adjusted for idle mix, float level and accelerater pump shot?

Bear

 

Hi Trent. I think that somewhere down the line, someone has wired 12v direct to the coil. If you have a voltmeter, check the voltage at the coil positive terminal. It should be around 8-9v or so. If it is 12-12.5v, wire in a ballast resistor between the switch and the coil.

If the voltage is too high, then the coil is probably shorted internally. Try another one. And make sure the distributor wire is going to the negative coil terminal.

One other thing, if you changed the condenser, unhook it temporarily, and see if that changes anything. I have bought new ones before, that were bad out of the box.

Since the rotor is melting/burning, you have way too much current flowing there, so check coil, condensor, pos/neg coil wiring, and ballast wire/resistor. Hope this helps some. Don

 

Great!
Bear, I assume all of that was checked out when the guy put it on. He was supposed to be a carb wiz but I do have some doubts. Nevertheless, he's got to be better than I am. Regardless, I think the evidence leans towards something with the ignition. If for no other reason, I am not getting a spark or combustion in the 7 and 8 cylinders. (in addition to no spark present between the wire and distributor, when I pulled the plugs in those two chambers they were wet with gas).
Don, Thanks a lot. You've given me some really good leads that seem to address the "burning issue" (hehe). Could I solve this whole problem by getting rid of the points for a new type of ignition? If so, what should I get and how involved is that?

Thanks to all of y'all for your help!

Trent

 

>...Could I
>solve this whole problem by getting rid of the points for a
>new type of ignition? If so, what should I get and how
>involved is that?

Trent,

While for many reasons you may wish to resolve the problem you apparently have with your breaker-point ignition, there's no question in my mind that an electronic ignition of any kind would be the way to go. You'll never have to adjust the points again, you'll get a hotter spark (better economy and power), etc., etc.

The options that come immediately to mind (in approximate order of expense) are:

- Buy a Pertronix unit to replace the points in your existing distributor. If you can replace points, you can install one of these. They simply drop in and while I've never used one myself, I understand they work pretty well. I think they run in the $60-$90 range.

- Go to a junk yard and pull the distributor, Duraspark module, coil, and all related wiring from a later model 302 equipped truck. Not sure what this would cost, though probably less than $75 or so.

- Purchase an aftermarket distributor and ignition module from a reputable company such as MSD. I believe MSD now offers a distributor with the module built in, so that would help keep costs down as well as simplifying the wiring. This should run you between $200-$400 depending on how you do it.

Hope this helps.

Bruce in South Carolina
1977 F-100 Ranger XLT
1984 Volvo 245 Turbo - it's a Ford now!

 

If someone has bypassed the resistor and you are currently getting 12v to the coil and you want to put in an electronic ignition then go with Pertronix. It is inexpensive and the coil will work with or without a resistor. I decided to go that route because of cost and ease of installation. It works great so far (about 1000 miles).

Mark

 

 

I can't help but ask if you checked ALL ground cables from chassis to frame, chassis to motor, etc.. body to frame.. Electric choke ground, all wires not burnt through touching metal.. It sounds like a grounding issue to me affecting your ignition directly, im pretty sure my 78 bronco did this to me

 

Uuuuummmmmm......did you notice this thread is from 2002.....?????