Help needed with plug firing/ignition problem

[Anonymous]

OK gents, my ignition woes continue. As stated prviously, my MSD fried this weekend so I replaced it with a stock Ford module to control the DSII. Strangely enough, it ran pretty crummy for the first few minutes. Then I tweaked the timing a bit figuring the different ignition would require it, then she ran pretty good...for a few days. Then going down the road 2 nights ago, something went wrong. She went from running smooth to sputtering a bit. I thought for sure I had lost another rocker arm cap bolt (happened twice before...same symptoms). I opened up the valve cover last night and other than needing some very minor tweaking to the valve lash, everything seems fine. :

Well, after another day of crappy running, I started experimenting with the plugs. I started with pulling them all to inspect. No surprise. They all were sooted up. I'm running really rich, but I know that. So I cleaned them all up and popped them back in. No difference. Well,not true. It's a little better but not nearlt where it needs to be.

Next, I decided to make sure I didn't have a bad plug or wire so I started pulling plug wires with the motor running. It didn't take long. I popped the 1st one off and the motor stumbled badly. I popped the 2nd one off and there was little if any change. All of the rest of the wires resulted in bad stumbling.

OK, so I've got a problem somewhere in the #2 line of things either from the DSII, wire, plug, ...or...

I tried a different wire...no change
I put a new plug in...no change
I cleaned the DSII top terminals off...no change
I even flipped the cap 180deg and checked...same problem so its not the cap

Well kids, what's next? It aint the plug or wire. Could it be a bad terminal on the cap? Everything looks ok there. Could there be something wrong inside the DSII causing just that terminal not to fire right? Could it be something internal to the #2 cylinder keeping that plug from firing?

Thanks as always gang!

 

[Anonymous]

Sounds like either a broken plug wire or a cracked cap. Are you using a wire puller to pull the plug wires? Look inside the cap for carbon from arking or a hairline crack.

 

[Anonymous]

i don't see anything wrong with the cap or wire. I even rotated the cap 180 degress so that the #2 cylinder would get a wire from a different terminal, but got the same results.

Can the magnetic pickup in the dizzie go bad or die? Can it be replaced without replacing the whole DSII?

 

[Anonymous]

If it’s not the cap or the wire and the problem didn't travel to another hole when you went 180 out, I'm thinking sparkplug maybe? Cracked insulator or melted electrode. If I recall your earlier post the compression is OK in every hole, right?
You know before you narrowed it down to one cylinder, I was thinking the symptom sounded like a coil going bad.

 

[Anonymous]

tried a brand new plug too. Nada.

I thinking one of 3 things:

1. spark is grounding somewhere at or near the plug keeping the juice from firing the plug
2. the ignition module is somehow only firng the other 5 lines (not likely though)
3. something is up with the inner working of the DSII. The magnetic pickup is bad in some way.

I just don't know at this point. I'm completely confused. I'm hopefully going to be able to scrounge cash together to get my new MSD tomorrow and we'l; see what happens then...but don't stop making suggestions!

 

[Anonymous]

Cover the boot near engine and wire near diz cap with dielectric grease coating. Use a loom to separate wires. Then try it.

Check resistance of wires. Are they MSD wires? If yes, and you suspect a bad MSD wire, they'll send you a new wire free.

They did for me.

Last ditch...contact me and I a have a box of old MSD wire stuff you might be able to make a good wire from it.

Steve-O

 

[Anonymous]

Thanks Steve. Should I coat the INSIDE of the two boots or the outside of the boots? I do have them all loomed. It's not a problem with the wire. I tried a different wire.

 

[simon]

1. spark is grounding somewhere at or near the plug keeping the juice from firing the plug
2. the ignition module is somehow only firng the other 5 lines (not likely though)
3. something is up with the inner working of the DSII. The magnetic pickup is bad in some way.

don't stop making suggestions!

considering #1: did you check for spark on the questioned terminal with a short plug wire and plug on bare engine metal? just to rule out false grounding.

considering #2: do you have access to another DS2 module (junkyard unit, or from a friend or such)?
Do you have access to an original points distributor?

finally #3: what exactly is wrong with the dizzy?


couple more questions: any idea why the MSD did fail?
how did it run before the MSD spark box died?

 

[Anonymous]

#1: that was suggested but it was also suggested that'd I'd get one hell of a shock doing it! Is that sae? Do I actually touch the plug to the block or hold it off a bit for arcing?

#2: no, i can go BUY another module for $25, but I'll probably be getting my new MSD box tomorrow anyway. No, I don't have an original dizzie to use and besides, I had a HELL of a time getting this DSII to drop in and line up (oils haft, etc).

#3: nothing is wrong with the DSII that I KNOW of...that's why I'm asking.

The MSD fried most likley due to moisture . I was cleaning the engine bay getting her ready for a show and I think I soaked it pretty good. Then, I probably tried firing it up too soon and the moisture hadn't evaporated/disipated yet.

 

[Anonymous]

#1: that was suggested but it was also suggested that'd I'd get one hell of a shock doing it! Is that sae? Do I actually touch the plug to the block or hold it off a bit for arcing?

You can put a screwdriver through the tip of the plug, hold the handle of the screwdriver and check for a spark that way. You'll need to turn the engine over but not start it.

I spread a thin layer of dielectric grease all over the inside of my diz cap. Also on the outside of the wires and boot covers. If they get some on the inside and the boot covers tend to slide up, just expand the metal part that goes into the diz to get a better (tighter) fit. The grease cannot hurt anything, it doesn't conduct electrucity and won't impede the spark from rotor to cap at all.

Good luck,
Steve-O

 

[Anonymous]

You can put a screwdriver through the tip of the plug

you mean stick a screwdriver into the boot and arc from the shaft of the screwdriver to the plug in place, right? I have an inline plug tester that you plug into the boot and onto the plug. It flashes with the spark firing so you can see if the current is getting TO the plug. What I don't seem to have is spark at the OTHER end of the plug, inside the head! I'm getting spark TO the plug (maybe a very weak spark) but that's as far as i can test. Is there a way to pull the spark, hook it to it's wire and fire the engine to see the plug itself firing? Do I need to hold it a special way, etc?

 

[Anonymous]

Bryce,

This is a long shot but, look at the reluctor and make sure that you have six teeth. Maybe one got broken off somehow?

 

[Anonymous]

wouldn't that cause the miss to happen at the same point of rotation (4 o'clock in this case for #2 cylinder) each time? That might be it! Long shot or not, worth checking!

Thanks Don.

ANyone else with some long shots?

 

[Anonymous]

Well, no luck there

The "spoke" that would seem to be the one that passes under the pickup when #2 should fire seems no different than the rest except that marking on there...some stamp of some sort? number? is it important?

WTF is the problem?!?! AARG! I'm pulling my hair out on this!

I pulled the valve cover once more just to make certain it wasn't in the rocker assemble, spring, etc. All is fine there.

How can I get #2 to fire in a different spot WITHOUT removing the dizzie? possible? i want to try to give it a known good spark and see what happens. That would eliminate one more thing.

 

[Anonymous]

new MSD = no change (well, not NO change. Everything else is firing smoother but #2 is still NOT firing.)

I pulled the plug out, hooked it to the wire and fired it up. The plug appears to spark.

That leaves internall (valves) right?

 

[Lazy JW]

It's time for a compression check.
Joe

 

[Anonymous]

0 (or close to it)

:x

what's next? what are my possibles? BLown headgasket? Cracked valve, broken ring?

the plug is sooted but not wet with oil, so probably not ring, right? Could it be a stuck valve (noting that the rocker arms SEEMED to compress the valves)?

 

[addo]

Dropped seat? Unbolt the rocker arms and see if all the valve tips are at the same height.

 

[Lazy JW]

Yup, I've seen valve seats pop out and just sit there crooked under the valve. Looks like the head needs to come off.
Joe

 

[Anonymous]

STUCK VALVE! Thank G_d!

I pulled the rocker arm and rapped lightly on the valve tip, rebolted the rocker assembly, and viola. I think it was too tight and holding the valve open.

I think we're in good shape...finally.