Duster Roars but wont start...help !

-
trevorcrum

trevorcrum

Well-Known Member
Joined
May 31, 2015
Messages
62
Reaction score
2
Location
tucson
Ok, this is a weird one.

My 74 duster was starting and running fine last week. Two weeks ago I think I flooded the engine, and after it sat a while it fired right up. The battery was tired, so I changed it out. Now this week it doesn't start.

Now here's the strange part.

When I try and start it, it roars like it's actually catching and at pretty high revs, but then immediately dies. I do it again, and same thing happens. Roar, and quit.

Now the first thing I thought of was to check the flooding again, as it's a Holley double pumper with line pressure around 7psi, which I know is too high. I bought a regulator I'll put inline. I pulled the plugs (they didn't smell too bad) and pulled the carb to help dry it out, but now I'm thinking it might be more electrical and perhaps I have a bad ignition switch which won't work in the "run" position.

Anyone know how I could diagnose this ? Or have any other thoughts why the car would start but then quit when placed in run ? The previous owner hacked the wiring pretty good, so I'll change that out shortly, but wanted to get your thoughts until then.

Thanks FABO's.
 
Hmmm, should have mentioned I have a 3 wire "ready to run" distributer. So no ignition box, and no ballast resistor.
 
trevorcrum said:
Hmmm, should have mentioned I have a 3 wire "ready to run" distributor. So no ignition box, and no ballast resistor.
Click to expand...

Well......I dunno. What you described is a classic ballast issue.

Maybe Del will jump in here.
 
trevorcrum said:
Hmmm, should have mentioned I have a 3 wire "ready to run" distributer. So no ignition box, and no ballast resistor.
Click to expand...

LOL As usual, need the link, brand and model.

"Generally" you take all the wires to the ballast and jumper them together, then use the old coil wire to power the new system

Bear in mind that the "ignition run" goes dead during "crank" ----So you still need the old brown IGN2 bypass wire hooked in there.
 
Sorry, the parts are Summit RTR 850028 Distributer, and MSD Blaster 2 - 8203 coil. I wasn't sure that I hooked it up correctly, but it has been running for the past month or two with no problems so I claimed victory. Perhaps a little early. I have left the other ignition wires in place for the most part, as I'm again going to swap out the harness shortly. The directions on the RTR were good enough to hook it up, but they didn't help much with the tear down of the old stuff....orange box, and ballast wires.

I know it sounds like I don't know what I'm doing partly because I don't but the old distributer was crap, and the new one was a relatively easy install.
 
trevorcrum said:
Sorry, the parts are Summit RTR 850028 Distributer, and MSD Blaster 2 - 8203 coil. I wasn't sure that I hooked it up correctly, but it has been running for the past month or two with no problems so I claimed victory. Perhaps a little early. I have left the other ignition wires in place for the most part, as I'm again going to swap out the harness shortly. The directions on the RTR were good enough to hook it up, but they didn't help much with the tear down of the old stuff....orange box, and ballast wires.

I know it sounds like I don't know what I'm doing partly because I don't but the old distributer was crap, and the new one was a relatively easy install.
Click to expand...

OK found this

summitracing.com/global/images/instructions/sum-850028.pdf


"Red lead to switched 12v (coil positive)
Orange lead to coil negative
–
NOTE: You must use a coil
with a .7ohms primary or LESS.
Black lead to engine ground"

I would start by checking for voltage in both "start" and "run" positions of the key

Get to the point where the distributor red wire connects, clip your meter there. Turn the key to "run" and check voltage which should be within a couple of tenths of a volt "same as" battery voltage.

Crank the engine USING THE KEY and take a second reading while cranking. Meter should again be close to "same as battery" whatever that might be during crank, and should be at least 10V or higher
 
Thanks for your help, I'll check that out. As you can see the manual, it doesn't really explain what to do with the old wiring stuff. Would be nice as they must realize that everyone installing this needs to know how to replace the old stuff.
So assuming that I don't get voltage in the run position, bad ignition switch ?
 
Just a crazy thought...could it be a fuel delivery issue? Screen/filter blocked? Once pressure is off enough fuel gets by to the accelerator pump for initial fire, then when it fires up the supply isn't there....happened to me on a friends car a long time ago...like I said, probably a crazy thought, but you said it was running for a month and then the problem arose....I would think you wiring it all funky would show immediately. Good luck!
 
trevorcrum said:
Thanks for your help, I'll check that out. As you can see the manual, it doesn't really explain what to do with the old wiring stuff. Would be nice as they must realize that everyone installing this needs to know how to replace the old stuff.
So assuming that I don't get voltage in the run position, bad ignition switch ?
Click to expand...

Maybe but I would check wiring, because it's been changed. The bulkhead connector is ALWAYS a suspect.
 
That was my initial thought, and the reason why I bought the pressure reg for the Holley. I't running at 7psi and I hear that's not where they like to be. I'll check for fuel as well. Thanks for the thought. Nothing is too crazy right now to check.
 
I wouldent worry over 7psi that should be fine I always keep mine at 7psi
 
So, no voltage when the key is in "run" between the "+" on the coil, and ground. I'm guessing I should be at 12V +/- a little or am I missing something ?

I didn't crank it and check as I'm a one man band and cant see the voltmeter with my hand on the key. But as it's firing up in start, and dying shortly after I'm assuming that I should see 12v across the coil and ground when in run....Correct ???

Thanks for all the support FABO ers.
 
YES. First thought is "ballast resistor." But if you are on the "key side" and no voltage......you have a problem. One way to be sure is go round to the blue alternator field wire, key, should have battery voltage there

You have a shop manual? Download one at MyMopar.com Latest there is a 73, and there will be "some" differences. I have a 74 paper manual, and can post relevant pages.

Just got done "producing" a 76 wiring pdf, guess I should get busy on the 74

Very first thing I'd check out is the bulkhead connector where the "ign run" comes through there

Another area---that Redfish has pointed out----I believe your car has a connector to separate the engine part of the harness, a "white" connector. Be sure to check that thing out
 
67Dart273 said:
YES. First thought is "ballast resistor." t
Click to expand...

Bad Sport said:
There isn't one.
Click to expand...

Well then I'd "hit" the bulkhead connector, and if that is not easy enough, pull down the column connector for the ignition switch, and examine it and check out the "run" wire

Also, 74 actually has an "ignition run" fuse

Manual says "cavity six" 6A but that sounds low to me.

k0of20.jpg


2zs0bde.jpg


b5l386.jpg


wlby3c.jpg


258402x.jpg


5ccape.jpg
 
What about disconnecting the ballast wires and putting an ohmmeter across the ballast itself looking for an open.
 
This looks extremely helpful. Thanks, 67Dart. It actually looks to be a 3A fuse in the ignition run cavity 6 spot. Is this scan from the 74 service manual ? If so I guess I had better invest. I'll look at the fuse, and run out the ignition switch. I put in a new battery recently and not sure if I got the correct one. Perhaps this caused the problem. I'll keep you posted and thanks again for the help.
 
The only place it says "3A" is in the one chart. That's what made me?? The diagram (which I did not post) and the fuse panel diagram (which I did, bottom photo) both say 6A. Frankly, I'd put a 10A in there.

I decided to scan the electrical diagrams and a few pertinent pages from the 74 diagram, working on it this morning. But yes, if you are "going to have" a 74, a shop manual would be wise. Don't know of a particularly good place, Efray is one, LOL
 
67Dart273 said:
Well then I'd "hit" the bulkhead connector, and if that is not easy enough, pull down the column connector for the ignition switch, and examine it and check out the "run" wire

Also, 74 actually has an "ignition run" fuse

Manual says "cavity six" 6A but that sounds low to me.


5ccape.jpg
Click to expand...

Looking at this diagram I had fuse #8 go bad. Would that cause my no start issue? I'm not sure what the letters and numbers next to it mean.
 
This may be out of left field but I had a similar problem when my Duster had a severe vacuum leak through the intake manifold. In my case the heads and intake had just been replaced. I think it is less likely in an engine that previously ran well...but maybe worth thinking about.
 
Hmmm, I'm confused now. The old coil had a brown wire supplying the + side. So I reused it on the Blaster2 +. I'm assuming this is the Q ignition starter wire. Now I am seeing that this wire is grounded in "run" and also with no key in the car. I pulled it from the coil, and still is grounded. This sounds like the problem. Suggestions as to where to look ?
 
It should not be grounded if "we" are thinking of the IGN 2 wire. You ARE talking about a factory wire?

The IGN2 circuit only goes one place........from the IGN2 contact on the ignition switch to the coil+ side of the coil, originally the coil + side of the ballast. I suggest you unplug the ignition switch connector, and unhook the wire from the coil. Check it to ground should be infinity (open).

Maybe the switch is bad. "I've heard" of them breaking apart internally. You can easily check it....accesss the connector there at the steering column.
 
It's factory, It's brown, and it use to go to the old coil + terminal. I don't have a diagram with it called IGN2, but above it's what I believe to be Q at the bulkhead, and I believe that makes it J3 at the steering wheel connector.

Strangely when I pull the connector apart, and check the engine side of the connector, J3 is reading grounded. So somehow I'm grounding between the terminal lug at the coil and the connector to the column ????
 
If you are not making a mistake, that is a big problem

But you need to be VERY specific. I don't know what "the connector" means.

You have the column ignition switch connector disconnected? And the coil end of the brown? Bad. Might be melted / crossed in the engine bay harness.
 
You must log in or register to reply here.
-

Back
Top