Need input from the brain trust; fuel or ignition redux

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VashonMopar

VashonMopar

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I just started my 1971 Duster w/stock 318 for the first time in many years (like more than a decade). I replaced the gas tank, fuel line, coil, distributor cap and rotor, and then changed the oil and ran it on several occasions for a total of about 100 miles. I fired it up again last week and got about a mile down the road when I felt the engine chug. I turned the vehicle around and went back in the direction of home and the engine backfired a few times and then died completely, leaving me to push the car back into the garage. It had totally lost spark, as far as I can tell. I then replaced the coil, cap and rotor, ECM, and ballast with new, and the car fired and seemed to idle ok; but then it would seem to lose power and quickly die again when I pressed the accelerator. I've got a brand new electric ignition and 4-bbl carb ready to install but I need help from some Mopar guys down the street, and I'd like to take it to them in working condition so they don't have to waste a bunch of time trouble shooting. I don't quite have the technical skills to upgrade the ignition (it's a Jegs kit that requires some extra wiring for the ECM). Is there something else I'm missing, or does anyone know off-hand what the problem is? Is this actually a carb/fuel problem?
 
VashonMopar said:
No, is there a dist pick up on a points-style distributor?
Click to expand...

?????????????????????????????????????????

In your original post you are talking about Mopar electronic ignition and the ECU. Thus you should not HAVE a "points" distributor............
 
67Dart273 said:
?????????????????????????????????????????

In your original post you are talking about Mopar electronic ignition and the ECU. Thus you should not HAVE a "points" distributor............
Click to expand...

No, I meant I have the new electronic one I need some help to install, but I don't have the wiring experience to make that work. Its still got the old points style distributor on it. I'm just trying to make it run long enough to get it to the guys that know what they're doing so they can install it.
 
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sounds like your running out of fuel. If it idles then you get on it and it falls flat and dies? After a decade the first thing I would replace is the fuel filter. Fuel to idle can pass a clogged filter but once you get on, it it never recovers, bogs and dies.
 
pishta said:
sounds like your running out of fuel. If it idles then you get on it and it falls flat and dies? After a decade the first thing I would replace is the fuel filter. Fuel to idle can pass a clogged filter but once you get on, it it never recovers, bogs and dies.
Click to expand...
See, this is my problem! Now I've replaced the fuel system from the tank to the pump, so if it's a fuel issue, it's between the fuel pump and the carb. And I recall that in high school I replaced the carb with another used carb I found in a junk yard (about the time fuel switched over from leaded to unleaded).
 
67Dart273 said:
I posted some info in this thread................

Diagnosing Distributor - No Spark Chase
Click to expand...
Also, what's giving me concern about just upgrading to the electronic distributor now is that the ECU has two extra wires. The black one is self explanatory (- terminal on the coil), but the blue wire needs to hook to the ignition run side of the ballast resistor. Am I safe to assume that's the side with the blue wires already on the ballast, and what can I do to test for that?
 
Wire colors don't mean much LOL I can't see them. Here is the simplified diagram...

Ignition_System_4pin.jpg


Bear in mind the diagram is "not quite right." ALSO bear in mind that the ballast resistor and coil wiring IS NOT CHANGED. Same as points wiring

So basically you:

Take the wire labled "new wire" coming off the ECU and add that to the "key side" of the ballast resistor

Make sure the ECU box is grounded

After removing the distributor, the wire shown in the diagram goes to coil NEG along with your tach if you have one

And of course connect the distributor pickup connector

You don't cut or remove any other wiring
 
troubleshooting an electronic ignition is no fun when you only want to drive the thing. Points are easy.
 
pishta said:
troubleshooting an electronic ignition is no fun when you only want to drive the thing. Points are easy.
Click to expand...

I almost suggested the OP try to troubleshoot the stock system and get that running AND THEN do the conversion. This might actually be a good idea.

"Some stuff" on points..........

Turn the key to "run"> Measure voltage at coil POS and coil NEG. If they are both "same as battery" or about 12V then the points are open or are not conducting. Remove the cap and inspect and bump the engine until the points are closed. Voltage at coil + should be somewhere in the 6--10V region, and coil NEG should be somewhere from "very low" to as much as a volt. (1 volt is actually high). If it's higher the points are not conducting, IE they are burned / dirty.

You MUST have a good condenser for the thing to make spark. There is no reliable way with simple equipment to test a condenser. Best thing is to buy one---or two---and try them.

You can also use a screwdrive/ jumper clip wire to mimic points opening. "Bump" the engine (keyin run) until coil NEG is "same as battery" You should be able to repeatedly short the coil NEG post to ground and get a "snap" nice spark each time. Do not test this with the coil wire........use a solid core wire "rigged" to a spark tester or opened up spark plug.

If this works, then get the points working. They must be gapped but you can do that by eye to test. Replace the condenser.

NOW measure coil+ voltage WHILE CRANKING and do so by USING THE KEY ot crank it. The voltage should be at least 10V and close to "same as battery" while cranking

Then check spark while cranking

BEAR IN MIND there are TWO different ignition switch circuits in play, here. The "ignition run" (key in run, the IGN1 wire) is not ONLY in run. It goes cold in "crank."

The brown bypass circuit, IGN2, is ONLY hot during cranking. This connects the coil direct to the battery, electrically.

It is important to understand the difference For example if you "test" for spark by jumpering the solenoid/ relay, you are not utilizing the bypasss/ IGN2 circuit. If that circuit has a problem, you will not "see" it
 
VashonMopar said:
I just started my 1971 Duster w/stock 318 for the first time in many years (like more than a decade). I replaced the gas tank, fuel line, coil, distributor cap and rotor, and then changed the oil and ran it on several occasions for a total of about 100 miles. I fired it up again last week and got about a mile down the road when I felt the engine chug. I turned the vehicle around and went back in the direction of home and the engine backfired a few times and then died completely, leaving me to push the car back into the garage. It had totally lost spark, as far as I can tell. I then replaced the coil, cap and rotor, ECM, and ballast with new, and the car fired and seemed to idle ok; but then it would seem to lose power and quickly die again when I pressed the accelerator. I've got a brand new electric ignition and 4-bbl carb ready to install but I need help from some Mopar guys down the street, and I'd like to take it to them in working condition so they don't have to waste a bunch of time trouble shooting. I don't quite have the technical skills to upgrade the ignition (it's a Jegs kit that requires some extra wiring for the ECM). Is there something else I'm missing, or does anyone know off-hand what the problem is? Is this actually a carb/fuel problem?
Click to expand...
Did you prove this or just start throwing stuff at it
 
pishta said:
troubleshooting an electronic ignition is no fun when you only want to drive the thing. Points are easy.
Click to expand...
See, in this moment, points are not easy
AJ/FormS said:
Did you prove this or just start throwing stuff at it
Click to expand...
Not quite sure what you mean. I did the fuel tank and line replacement as part of the upgrade to 3/8" and a new sending unit (and did a brake job and put the -002 and -003 springs at the same time). After she stopped working, I started replacing ignition components one at a time until she fired back up. The problem is not resolved, which is why I'm soliciting group help. I think my next stop is points/condenser, per previous poster.
 
AJ/FormS said:
Did you prove it lost spark, not a trick question?
Click to expand...
No...and I'm not sure even where what/component would have lost spark. I'm down to points and condenser left before I move over to fuel. Everything else on the ignition is brand new.
 
OK wait
I need a translator, anybody out there?
One more time
Do you know,
not best as you can tell,
not guessing,
but
do you know for a fact, that
the ignition system has failed ?
 
This could be just about anything from misadjusted points to a loose fuel line clamp, and everything in between.
Follow 67Dart273 (Del's) advice and step by step track it down.
Print his instructions and take them out to the car with you.
 
TrailBeast said:
This could be just about anything from misadjusted points to a loose fuel line clamp, and everything in between.
Follow 67Dart273 (Del's) advice and step by step track it down.
Print his instructions and take them out to the car with you.
Click to expand...
Already on that...more to follow.
 
You should follow the proper procedures in diagnosing the problem 1st.
When cars sometimes sit for a long time things like a carburetor gaskets drying up and or some spark plug wires being chewed on or just wires in general being chewed on by vermin are to be expected. Now throw points into the mix... And that's something that can fail at any given time, lose those points n upgrade the ignition to electronic magnetic pickup style asap.
 
turn ignition on, lay the coil wire on the exhaust manifold so there is a small gap and manually open the points with a popsicle stick, it should spark every time you open them. That will prove the coil and condenser is working. Set the gap, and your done ignition wise. Now you just need to time it. How do new points fail to the point of stranding you? I can tell you how an ECU can. Im just trying to be practical. You got to learn to walk before you can run.
 
Folks, thanks so much for your input. Especially the extensive input from 67Dart273 and the personal tutorial from AJ/FormS. Turned out to be points/condenser (takes a little bit to get parts to the island). She's firing now, holding RPM, and revving more or less as she should. I haven't had a chance to test drive yet, but there's a little car show about two miles down the road tomorrow that should make a great one. They have a tow truck there if there's a serious issue. A pretty serious tune-up later, and we should be about dialed in. This stuff can be a little scary, it's nice to have a backstop.
 
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