possible duraspark going bad again?

[carbed87]

i posted about this back in april. my bro has an 83 fairmont with the 200 I6 in it. it's had just about everything replaced, plugs, cap, wires, rotor, fuel pump, filter, alternator, t-stat and hoses, catalayic converter, ignition module (the thing labled duraspark), both battery cables and the battery.

the problem is, i replace the duraspark unit early this summer, it seemed to do the job but now it still seems as though it's sputtering after about 5 miles of driving. after letting it sit for around an hour it will go again, but it will keep doing this until you get home.

and to make matters worse, it seems to have a slow drain on it. the alt is brand new (like 0 miles) and we tested and charged the battery at the parts store, i put it on and it started.....the next morning? hell no haha, dead as all hell.

i thought buying a simple carbed car would kind of eliminate the possability of strange problems like this...guess not.

any ideas guys?

[carbed87]

heres the link to the original problem. it has a little better description of whats going on:http://vb.foureyedpride.com/showthread.php?t=74921

[Greywolf]

Have you done the voltage regulator, and/or checked the voltage while running?
Aside from the slow drain (which may or may not be related) it still sounds fuel related. I'd run the tank low on gas, then drain the tank into a jug and see how dirty it looks. Those tiny filters on the carb itself are nearly worthless--they clog fast, don't let you see how much dirt is in there, and tend to eventually strip out the threads in the carb itself.

Stick a clear filter in the line before the carb, in an easy to see and service location. Also, once the tank is empty pull out the pickup under the car and see how grungy the pickup is.

As far as the slow drain, get a test light and remove the negative lead from the battery. Attach one end of the test light to the battery and the other to the negative lead, so all power has to flow through the test light.
Leaving the key out and door closed (so the interior light stays off), pull the fuses one by one and see which one(s) cause the light to go out.

The battery is draining through that circuit or circuits. If it stays on with all the fuses out, you have a problem with something like the starter solenoid, alternator, voltage regulator, or something similar.

[carbed87]

some very good ideas, thank you very much. for the time being i just put one of those battery disconnect switches on the neg. terminal lol

[Greywolf]

i just put one of those battery disconnect switches on the neg. terminal lol

Those switches are great. Even better, you can just put the test light tip on one part, and clip the wire end to the other, without having to pull the whole cable off and juggle it all around.

Makes the testing about 10 minutes faster.

[carbed87]

so where is the voltage regulator on these things.


i took the batt off the charger last night but left the disconnect OFF. i guess my bro hooked it up today and made it about 30 feet before it died. the wierdest part is all it would do is click when he tried to restart it, the damn battery was dead after it starting and idling for about 5 min.

[Marz]

Also, take a look at your wiring. Bad connections will make the car run like crap.

I went through my 85 Mustang engine harness and rebuilt it. Used existing wires as well as replacing any bad ones with good wires I found at a salvage yard. I usually pick a harness form the same period up once in a while just so I can use the wires.

[JACook]

So, about this replacement Duraspark module- Was it a Motorcraft module? Was the
original one? Do you still have the original one?

I've said many times, most factory Duraspark modules are replaced needlessly, and
usually with a low-quality aftermarket box that doesn't last. Then people get this
idea that Duraspark ignitions are no good, and just chuck the whole thing.

If you still have the original module, and it's Motorcraft, put it back in.

[Greywolf]

Voltage regulator is on the inner fender, near the alternator. I think it's usually under the starter solenoid. It's a little (usually silver, or was once silver...) box the size of a wallet or so, with 4 or 5 wires coming out. Several of the wires go straight to the alternator.

Actually, while you're there, check that the connections are clean, especially where all the wiring connects on that one terminal of the starter solenoid, and on the back of the alternator. A little corrosion makes a big mess on these cars...

[MAD MIKE]

I've said many times, most factory Duraspark modules are replaced needlessly, and
usually with a low-quality aftermarket box that doesn't last.

Agreed. Standard and Nieoff(Borg-Warner) brand ignition boxes are a crapshot. The Duraspark boxes do work very well.
I have had my share of failed pickups. I did not see this mentioned as being replaced. The pickup can fail, and lead to a stumble. Often hard to diagnose as the pickup may work fine when cold but when heated may short or open. It may test out OK, but usually the conditions that cause faulty running cannot be reproduced on a test bench.

[carbed87]

pickup? like fuel pickup? i talked to a friend of the faminly who is a ford tech and he said it should be the carb

[carbed87]

it's getting spark and fuel when it won't start by the way. voltage regulator has been replaced

[MAD MIKE]

pickup?

It is the electromagnetic pickup inside the DuraSpark distributor. The wire harness that connects to your ignition module from the distributor is a hall effects device. This is the device that replaced the points. It can become heat soaked from prop wash, and the insulation can degrade over the years.

[JACook]

it's getting spark and fuel when it won't start by the way. voltage regulator has been replaced

Getting spark where? Spark coming out of the coil is only the first step. Are you actually
getting spark at the plugs?

When it dies, have you popped off the distributor cap and looked for condensation on
the underside of the cap?

[carbed87]

can i get that pickup from the parts store?

how do you check for proper spark at the plug with that big boot on there.

[MAD MIKE]

can i get that pickup from the parts store?

Yes. Ask for ignition pickup or ignition stator. ~25 greenbacks.

how do you check for proper spark at the plug with that big boot on there.

A spark will jump if you hold the boot close to a grounded object, the spark will be fairly audible as well. You'll feel it if the insulation on the wire has degraded.

[JACook]

how do you check for proper spark at the plug with that big boot on there.

Redneck way is to stick a philips screwdriver in the end of the plug boot and hold it near
something metal. (Hold it by the handle, of course.) Non-redneck way is to get one of
those test plugs from the parts store. Looks kinda like a spark plug with a big clip attached
to it. You connect the test plug to the end of the plug wire, and clip it to something metal.

[1nine84GT]

put a msd on it.

[Greywolf]

put a msd on it.

Won't help the problem he's already having...if it's fuel, no amount of spark will turn the engine, and if it's spark, a big lack of spark versus a little lack of spark won't turn it either.

Short of converting to a coil pack or DUI system, the Duraspark is as good an ignition system as you could hope for on a stock I6. But after about 30 years, even the best systems can be a little tired.

[JACook]

MSD, DUI, or coil packs would provide exactly -zero- benefit on a stock I6. Stock six can't
even benefit from having the rev limiter, since it's pretty much already got one sitting right
there under the air cleaner.

Ignition systems are not magic. If the existing ignition can reliably ignite the air/fuel mix,
the highest energy aftermarket ignition in the world can't ignite it more. Don't buy the
marketing hype.

The stock Duraspark ignition is already overkill for a stock six banger. Or even a pretty well
modified one.

[Greywolf]

The stock Duraspark ignition is already overkill for a stock six banger. Or even a pretty well modified one.

Spot on what I meant to say yesterday. I should have had my coffee BEFORE I posted. I meant that the Duraspark is one of the best systems out there for a mild application until you start looking at coil packs or DUI type systems.

If one is going to go through the trouble to upgrade to DUI or coil packs then they've hopefully gone through the trouble of upgrading the motor to suit.

I think one of the reasons for the legendary longevity of the 200/250 six is that it's built more like an industrial tractor motor than an automotive one (and the 300 truck six is the same way).

[Mad Max]

try checking all the connectors. Give each wire a small tug where the enter into the conector Had one where harness and connectors looked fine but one wire had an end that (the part that crimps on to the wire) oxidized away. It was making contact for about 1-5mins after startup then it would sputter for a while then die.

Maybe clean the contacts too

That's my $0.02

[carbed87]

great, im gonna try an electromagnetic pickup later this week, maybe today and we'll see what hapens