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71NewYorkMan

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new electronic ignition,
Brand? Type?

The one I took out was a Pertronix unit
The Pertronix was using the original ballast resistor and ignition coil? Or Flamethrower coil?

The present ignition system/resistor/ignition coil are all matched?

Any Pertronix related wiring changes have been changed in favor of the new system?
 

Matt Conlan

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Thanks for all the suggestions. It's a brand new fuel pump as of last summer. when I crank it, gas comes through in a steady stream. Just checked the carb - blew it out, checked the float, etc. The distributor is brand new. How would I check for spark as its dying? As far as the brand, I bought the ECM, resistor, distributor and new coil from Rick Ehrenberg, so not really a brand name. The Pertronix had the old Flamethrower coil, but it never ran right. I rewired the ignition system as I was putting in the new system. Should be all new.
 

CBODY67

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FWIW, I like the Holley 2210-family 2bbl. More refined and efficient than the Stromberg WWC and Carter BBD that it replaced. It does have the same issues with the air horn raising in the center due to over-tightening of the air cleaner wing nut as the Strombergs did. The BBDs had their air cleaner stud attached to a heavy wire which attached to the sides of the air cleaner mounting area. But when the air horn deforms, it breaches the float bowl's rear wall and where it seals against the air horn, allowing raw fuel to be pulled into the venturi area when the choke valve closes. One tip-off that this has happened is when the choke valve hangs on the air horn, adjacent to the air cleaner stud. BUT Chrysler put out a TSB and "Bridge Kit" to fix it in 1972. And it worked well as I did that on our '72 Newport 400 2bbl. BTAIM

When it dies after being run for a while, that's when the inductive timing light can be handy to have nearby, plus a long flat-blade screwdriver to short across the starter relay with the key in "run". Not specifically to check the spark timing, just to check for sparks happening.

Problem is that "spark" and "fuel" issues can tend to act the same in some situations. Making it difficult to diagnose correctly.

I have a '68 Buick LeSabre 350. After I got it, I did the normal tune-up stuff to establish a baseline of sorts with it. Plugs, points, wires, etc. One day I had it running and it started to lose rpm. I quickly went to the driver's seat and started pumping the accel pedal and it came back. No real rhyme or reason, but it happened unexpectedly, otherwise running fine. It would do it running down the road, too. The last time it happened I was taking it to my shadetree shop for storage. On the way there, it started dieing out. I'd coast to the shoulder of the access road, put it in "N" and try to start it by pumping the accel pedal quickly until it would catch, then I'd quickly pop it into "D" (one wheel on the dirt) and seek to continue to the shop. That night, it happened a few times, but we finally got there and parked it inside. I got a new fuel pump for it, for good measure.

One night, I decided to replace the fuel pump, just to know that it had been done. When I started it that night, it sounded better than it ever had since I'd owned it. Problem solved. Obviously, the existing pump had some issue with the valves in it where they would get into a particular position and leak internally between themselves (or something like that). I remembered a late uncle who had a similar situation on his '60 LeSabre. Back when you could rebuild fuel pumps! It was the valves in that pump having issues, too.

Then, the issue of fuel pump pushrod wear has come up in this forum a good bit lately, too. Something not usually worried about.

In one respect, it might be ignition as you can get it to start with greatly-advanced timing. Which is where the timing light checks can come in. On the other hand, it could be a fuel issue.

The fuel pump might be recent, but even with ethanol-resistant diaphrams, allegedly, if the pump is allowed to dry out from non-driving/running, that "resistant" diaphram can allegedly become brittle and have durability issues. But the pump can oily pump so much with a worn fuel pump pushrod (think "decreased lift on the cam lobe" sort of thing, resulting in lower volumes pumped). Maybe a little bit of both?

Please keep us posted on your diagnostics,
CBODY67
 

Matt Conlan

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Thanks! Will do. Gonna be a few weeks, it's take the youngest daughter to college week. Then, no kids! Lots of time for Newports! I appreciate all the ideas. I'm a self-taught tinkerer, never had anyone to work on stuff with. I can do the work, but my lack of experience sure shows in diagnostics. Been driving Newports since I was 16. Not gonna let this one get away from me now.
 

Ripinator

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Thanks! Will do. Gonna be a few weeks, it's take the youngest daughter to college week. Then, no kids! Lots of time for Newports! I appreciate all the ideas. I'm a self-taught tinkerer, never had anyone to work on stuff with. I can do the work, but my lack of experience sure shows in diagnostics. Been driving Newports since I was 16. Not gonna let this one get away from me now.

Based on everything you've said, I suspect the problem is associated with a bad ECU or ignition coil. Bad coil problems are especially insidious, because everything appears to be fine during diagnostic tests in the driveway. . . Until the coil gets hot later out on the road. I would try and find a US-made coil somewhere, and go from there - even a used one. Also, if there is a Chinese ECU in the mix, I would replace it too.
 

70bigblockdodge

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They are talking about the pick up coil in the distributor, it creates the signal that the ECU turns into a open in the ignition coil.
When they get hot they sometimes do not work. When they cool off they start working again. I have never had on create a driving problem only hot restarts.
That or the vibration dampener slipping is where I would look.
 

Ripinator

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They are talking about the pick up coil in the distributor, it creates the signal that the ECU turns into a open in the ignition coil.
When they get hot they sometimes do not work. When they cool off they start working again. I have never had on create a driving problem only hot restarts.
That or the vibration dampener slipping is where I would look.

Sometimes ignition coils behave the same way as defective pickup coils, when they get hot. . .
 

Matt Conlan

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Do my damnedest to keep Chinese parts out of my cars. My understanding with the Ehrenberg parts is they are made here. So, new coil, new ECU and new distributor. I'll try switching things out to see if I can find the bad one. Don't know how I can test the pickup, though.
 

halifaxhops

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Sometimes ignition coils behave the same way as defective pickup coils, when they get hot. . .
Yup ECU's also. RE boxes are about as good as you can get now. Way to many fake mopars out there now especially the orange ones.
 

1970FuryConv

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I suspect a partially plugged exhaust. If you vacuum test it and rev to 2000 rpm, does vacuum slowly decrease. Perhaps it starts out breathing fine, but back pressure from a clogged exhaust stops letting your engine exhale. Then you stall.
 

1970FuryConv

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You know, that kinda what I was thinking. I'm going to have to figure out how to test that. Thank you!
All you need is a vacuum gauge and a port for manifold vacuum on the carburetor. Connect the hose from the gauge to the port. Start it. Bring up the rpms and see what happens. If the gauge needle starts dropping, Houston we have an exhaust problem.
Another test is to cut out a small section of pipe in front of the muffler. Usually the muffler is the culprit. If it starts after a no start situation, you will have loudly found your problem.
Best of luck, Matt! Ben
 

WOT440

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I suspect a partially plugged exhaust. If you vacuum test it and rev to 2000 rpm, does vacuum slowly decrease. Perhaps it starts out breathing fine, but back pressure from a clogged exhaust stops letting your engine exhale. Then you stall.

I had this happen with a clogged catalytic converter. Ran good in the driveway and crapped out after ten/fifteen minutes of road driving. Never died, just had no power. I dis-connected the exhaust to test it.
 

Gerald Morris

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Based on everything you've said, I suspect the problem is associated with a bad ECU or ignition coil. Bad coil problems are especially insidious, because everything appears to be fine during diagnostic tests in the driveway. . . Until the coil gets hot later out on the road. I would try and find a US-made coil somewhere, and go from there - even a used one. Also, if there is a Chinese ECU in the mix, I would replace it too.

"Bad coil" is MY speculation at this point, though with electronic ignition, the pickup or ECU also are suspect. I would try another coil for my sanity check with such symptoms. They can be had cheaply enough. I'm putting a new Taylor Cable one on mine this Fall, when I replace the distributor. I stick with breaker points.
 

Gerald Morris

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I suspect a partially plugged exhaust. If you vacuum test it and rev to 2000 rpm, does vacuum slowly decrease. Perhaps it starts out breathing fine, but back pressure from a clogged exhaust stops letting your engine exhale. Then you stall.

Had this happen on a '76 Chevy I drove during the early 1980s. I've tried to avoid anything with catalytic converters after that, but its getting harder to do so now....
 

Slap Stick

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Timing chain and gear was replaced last year. Worked fine after that. I have not driven it at the 30 deg. BTDC, it sounds really nasty. When I start it and then bring it back down to about 12 deg. It starts right up. Sounds real good. By "nothing," I mean it won't turn over. The starter cranks and it gets gas but won't fire. I don't see how it can go "out" of timing. It is a new distributor. Can that be slipping?
Let's get some terminology clear. "Cranking" is the same as "turning over".
At least in my neck of flyover country.
 
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