Ma Mopar
Simple is Good
Simple is Good
Rus
Rusty-I love this! A little good-natured ball busting really makes me feel like I belong. Seriously, I am really impressed by the enthusiasm of this group. I apologize that my posts have been brief and infrequent over the last several days. I have been working way too much but hope to make some progress this weekend.
I fired up the car 2 days ago for the first time this year. Problem persists, but it was backfiring out the driver side!!!???
Did I hallucinate that it was the passenger side all last summer? The backfires were much less frequent though. Maybe 1 every 5 minutes or so. I think because it was cold out? So it was tough to say if it was ONLY the driver’s side. So now I am not worried about that slight header leak.
Another thing (and this is an important detail I forgot to mention to you.). It always is worse when the car is idling low. If I have my foot on the gas and keep it at 11 or 1200 RPMs, it backfires less. With the car in gear and the rpm dipping between six and 800, it backfires more. My brilliant buddy asked if maybe my voltage is dropping, and the ignition box can’t do it’s job if the voltage gets too low. I think he may be on to something. Alternator looks ancient. Maybe at idle the alternator just can’t get it done...? I thank you all again for your knowledge, patience, and humor. I will be looking into this tomorrow. This is a great group!!!
-Jay
Heck we even have simple One Wire
Mopar Points Distributors around for this very type of diagnostics.
Distributor wire to (-) negative side of the coil and one hot wire to the (+) positive side of the coil, ready to test.
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People are chasing this back to an ignition problem.
Here is a cure !
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Simple is Good
Has anyone mentioned wires cross firing? Chrysler put out a service bulletin describing how to route and shield the wires on my 360 engine because of an idle misfire. Turn out the lights and you’ll see the sparks if any.
See you have the Red MSD Box for the ignition, they are known to give trouble.
Drag race buddy is saying the MSD boxes are a racing item are finicky and give trouble. If you want a good running driver go back to the Mopar Factory Ignition, less headaches.
See if you can set up a mopar brain box ignition and test that on there, your problem will probably go away.
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The OP said it is a Mallory ignition box, not an MSD. I’m betting it’s fat at idle or it has a bad exhaust valve.
Should we assume the firing order is correct? Ive done that on 5 and 7 before by mistake.
Excellent idea! I have a points distributor too.Heck we even have simple One Wire
Mopar Points Distributors around for this very type of diagnostics.
Distributor wire to (-) negative side of the coil and one hot wire to the (+) positive side of the coil, ready to test.
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“We’re real dudes, not 80’s metrosexuals”Good cause that's how I meant it. Good natured. Too many sissies on this forum take stuff like the wrong way and get their britches waded up and hide under the kitchen table. lol This is an automotive forum, not a Hello Kitty forum. We're real dudes here, not some 80s metrosexuals. LMAO. You fit right in.....you'll find whatever this is.
I'm too lazy to go back and see.....what carburetor is it again? It could be that the carburetor just needs to be richened up a hair. I'm never on board with any experts of gurus when they part with what's always been the tried and true method for determining pops through the exhaust and that's a lean mixture. Somehow, some way, that's dang near almost without exception what it is. Remember, when engines are cold, they need a richer mixture until they get some heat built up. That's the whole purpose of the choke. If you're right on the ragged edge of being too lean across the board, you can get what you have. That's why I recommend fattening it up some just to SEE what you end up with. If nothing else, it will confirm or eliminate that as a possibility.
Correct6% and even is what I recall
Compression test was "good" with no numbers quoted.
“We’re real dudes, not 80’s metrosexuals”
Too funny man!
Anyways, carb is Edelbrock 800 thunder AVS. It had a holley 850 hp on it that I switched out in my troubleshooting. But that did not fix the problem. I think carb is unlikely to be the cause.
Yes. But.... I am definitely going to recheck it. That’s how sure I am.Ok, I tend to agree there. An 800 anything is rich enough to avoid a lean pop when cold so I don't suspect that anymore. Are you 100% sure on the firing order?
See you have the Red MSD Box for the ignition, they are known to give trouble.
Drag race buddy is saying the MSD boxes are a racing item are finicky and give trouble. If you want a good running driver go back to the Mopar Factory Ignition, less headaches.
See if you can set up a mopar brain box ignition and test that on there, your problem will probably go away.
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Yes. But.... I am definitely going to recheck it. That’s how sure I am.
lolThat’s how sure I am.
Are you going to post some pictures of your plugs? Putting a points distributor in there won’t fix anything IMO.
I am first going to check voltage at idle. If normal, then I will try again to see if backfire is confined to only one side or if it is both sides. I don’t want to exaggerate, but I have had the plugs in and out roughly 240,000 times in the last 8 months. They are a little dark, but not oily. No signs of detonation. If I get stuck I may post some pictures. A week ago, what I really needed were ideas. You gave them to me in spades. Now, what I really need is a day off to work on this thing. I will let you know what I find.Probably not, but it might eliminate some things. It's better than doing nothing, right?
I am first going to check voltage at idle. If normal, then I will try again to see if backfire is confined to only one side or if it is both sides. I don’t want to exaggerate, but I have had the plugs in and out roughly 240,000 times in the last 8 months. They are a little dark, but not oily. No signs of detonation. If I get stuck I may post some pictures. A week ago, what I really needed were ideas. You gave them to me in spades. Now, what I really need is a day off to work on this thing. I will let you know what I find.