Intermittent miss - NOT Snotty's

70_NPORT

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Yeah I read Snotty's thread but I think this is a bit different......
I noticed a slight miss at idle ever since putting the car back on the road after getting my disc brakes done. Tonight it got worse, way worse. I fired it up in the driveway and the engine sputters on and off at idle speed....almost sounds like a big choppy cam. Backing down the driveway and putting it in drive it almost cuts off until I give it some rpms. Ditto at the red light. It seems to smooth out at higher rpms (but still feels rough). I have a spare coil/VR/and even ECU laying around...so I guess I'll try one part a time. I can't find any vacuum leaks topside. Missing anything?

ps. yea I know there's no fan shroud, stan.
pss. and the radiator hose is funky, yes stan.

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Where does your vacuum hose for the booster connect? How old are the spark plugs and wires? Are the spark plug wires in wire holders so they are away from anything hot? It sounds like you have a ignition miss and the cause is usually a plug or wire that's the reason for the above questions.
 
Where does your vacuum hose for the booster connect? How old are the spark plugs and wires? Are the spark plug wires in wire holders so they are away from anything hot? It sounds like you have a ignition miss and the cause is usually a plug or wire that's the reason for the above questions.
Ok. Think I found it. The head of that nipple was so dry rotted that it just crumbled when I touched it lightly. The big one looks dry rotted also...heat I suppose. I've got fresh extras laying around......hope that's it.

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Ok..so that took care of the miss...totally gone. On the way back from the drive however, the engine backfired through the exhaust and cut off. I pulled off to the side of the road and came to a stop. I pumped the gas and turned the key and it started right up again with no problems all the way home. Backfire through exhaust is a dead cylinder?...which in itself is a symptom of a larger problem. Had a similar problem a long time ago with the same action...backfire and shutdown. Turned out to be crappy MP ECU.
 
Glad you found that bad nipple - they will make a car run crappy.

One thing I was thinking while reading your original words, is your choke properly connected? When I replaced the valley pan gasket, I found that my choke was not connected at all - it ran TERRIBLE when cold, and often backfired. Problem is gone with the rod properly installed.
 
Glad you found that bad nipple - they will make a car run crappy.

One thing I was thinking while reading your original words, is your choke properly connected? When I replaced the valley pan gasket, I found that my choke was not connected at all - it ran TERRIBLE when cold, and often backfired. Problem is gone with the rod properly installed.
Thanks snotty. The choke is electric and is definitely connected. It back fired once under load and cut off. I had replaced the plug wires before this event...it was time as most were burned or brittle.
 
Whats going on with this coil wire? Do you have the coil mounted on the fenderwell? I'd shorten it up and put the coil back on the engine. It's too long and the vibration etc. from the engine will damage it. Yea, I know, race cars sometimes have the wire like that, but they are using solid core wire.
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Whats going on with this coil wire? Do you have the coil mounted on the fenderwell? I'd shorten it up and put the coil back on the engine. It's too long and the vibration etc. from the engine will damage it. Yea, I know, race cars sometimes have the wire like that, but they are using solid core wire. View attachment 82353
YeH, its on the fender wall. I went thru two coils until I found out they want to be cool (as possibly can). I put third one on the fender and BINGO. No more dead coils. I drive my car a lot, everyday in fact. I could move it closer (shorten up the wire distance) but I don't think it'll make that much of a difference, PLUS that places it closer to the exhaust manifold (more heat). Nope, I gonna stay where its at.
 
So all sounds well then? I swear I can hear an intermittent irregularity. Well, maybe it is just me.
 
Ok this is driving me bananas. Yesterday I went out for a ride. The engine started up ok but as I put in reverse to back down the driveway it stumbled a bit until I put it in drive and brought the rpm's up.
I came up to the light and idled in drive and stumbled and cut off. It took a couple starts until the engine would fire up again. I get out on the highway and its great. I let up off the gas a bit after doing 65-70 mph and it backfired through the exhaust once. It seems to run great at high rpms, but at idle it will sputter and shut off unless its put in nuetral gear and I keep my foot on the gas to keep rpms up.
The last time I had a problem similar to this the orange box was malfunctioning. The engine would backfire through exhaust while on the highway...then the ECU/orange box completely failed.
Time for new one?
 
How's your PCV? A bad one will allow the car to run great under throttle, but at idle, no.
 
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Hard to tell, wouldn't hurt to have a spare.
Along with a new BR and VR, and Fusible Link....yep, been there..done that...got brochures to prove it. Lol
I know many of these "orange" boxes come from the peoples republic of china.....guess that says everything.
 
Along with a new BR and VR, and Fusible Link....yep, been there..done that...got brochures to prove it. Lol
I know many of these "orange" boxes come from the peoples republic of china.....guess that says everything.

Yea I consider that a basic old Mopar survival kit.

I wasn't aware the new boxes were from China, that explains a lot.
 
Yea I consider that a basic old Mopar survival kit.

I wasn't aware the new boxes were from China, that explains a lot.
yes...i think i had one the last time...i hear they are all made by communists now...how ironic
 
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