Intermittent miss

Snotty

Old Man with a Hat
FCBO Gold Member
Joined
Aug 18, 2015
Messages
5,060
Reaction score
3,974
Location
Fresno, California
Two weeks ago I changed the exhaust manifold gasket on the 440 in my Newport. I have needed to do this every 5 years or so. I know, I should remove the manifolds and have them planed. This is easier. Ha!

OK, so, last Friday I pulled the intake and replaced the valley-pan gasket. When I fired it back up and took it for a drive it was running on 7 cylinders. ??? I didn't remove any plug wires. Stared it today for the first time since; it ran fine, but about 300 feet from my home it went to 7 again.

Any ideas? I'm thinking I loosened a plug wire.

One good note: my car has run like crap when cold for over 4 years. Hard to start after sitting for two days and really chugging and spitting until it was warm. When I removed the intake - and carb as one unit - I noticed the choke was actually disconnected. The "Jesus clip" on the choke rod was gone. I replaced it - the car started today on the second spin of the starter! Idle was great and... wow! It has not run like this since I moved to Chico in 2011. So, while I'm disturbed about the miss, I am very happy about this!
 
I've actually had the number 7 plug wire pulled off more than once by my steering column. Wire was hanging too low and when I took a turn it started running rough. Opened the hood. Sure enough the wire was off. Reattached the wire thinking that's odd. Then it happened again the next time I drove it.using the wire looms now...
 
I've experienced that too. It's on the even-bank side as evidenced by the exhaust note. I think I loosened up one of the wires on the distributor when removing the intake. Haven't checked it yet. Was going to do so today but it's raining.

Don't want the car to melt. Ha!
 
so snotty, why would you ask for assistance before checking the obvious? you seem to think it is a loose plug wire. it would have taken less time to check that then punching buttons on your computer. :elmer:
 
So how did the manifold gasket turn out? Any leaks?
Very well, except for the miss. I was gone since last Wednesday; did a Kairos Ministry in Folsom Prison. Hoping to look at it this week now that I'm home again.
 
so snotty, why would you ask for assistance before checking the obvious? you seem to think it is a loose plug wire. it would have taken less time to check that then punching buttons on your computer. :elmer:
Just as a matter of conversation. Perhaps one of you have had a similar experience and can suggest something not so obvious.
 
Finally got around to checking all of the wires. All look good and tight yet the problem continues. So, having experienced a similar thing four years ago I decided to do what I didn't then - swap all of the wires. I found the bad wire then and simply replaced it with a spare I had.

Sounds easy, but in Chico it's not! I went to the local NAPA store - they're out, but was told the one across town had a set. Having been there twice that day I went home. The next Monday I walked to the Auto Zone Store. Out, would need to order them; none in their other stores. So, last Thursday I'm across town again and hit the other NAPA store - don't have them and tells me they didn't a week earlier either. I had them order me a set; tomorrow makes a week.

It's times like this when I miss Bakersfield. Would have had them by now. I cannot believe a set of Mopar 440 wires would be so hard to find in this town.
 
You know, I almost said, "What about a set for a 413?" just to see what the guy would do. Decided not to....
 
Same thing here. Tune up parts are getting hard to find. You guys have any idea where to find a brass terminal distributor cap?
* at a local chain?
 
Same thing here. Tune up parts are getting hard to find. You guys have any idea where to find a brass terminal distributor cap?
* at a local chain?
To my more recent experiences and research, it appears that the parts industry I used to understand has been evolving into something I don't. Too much manufacturing has been moved and brand names sold or no longer active... even stuff I bough previous is different than last time I purchased... same PN... And please tell me who has an accurate online guide to help solve this.

The entire business is changing, maybe not in our favor either... if you find a good product, you might want to stock a spare.

BTW I hate dealing with the online versions of the store companies... I never leave the counter without opening the box and inspecting... a few years back Advance sent me used ball joints for my online order... and the local store didn't want to deal with it until I got the online side on the phone. Napa destroyed my loyalty about 15 years ago over a warranty issue with an alternator that I did follow all the way up the food chain... I would guess I have directed at least $150k away from NAPA since then... I hope the NAPA FL district manager reads this and remembers the Benz guy with the Buick alternator he chose not to cover...

Just as a matter of conversation. Perhaps one of you have had a similar experience and can suggest something not so obvious.
Snotty and anyone else curious... next time try spraying a little water on the ignition components while running, weak secondary insulation usually will arc and you will hear a snapping noise even if you cant see it... do this in the dark for a fun show if you have a weak one... or really aren't sure.
 
Snotty and anyone else curious... next time try spraying a little water on the ignition components while running, weak secondary insulation usually will arc and you will hear a snapping noise even if you cant see it... do this in the dark for a fun show if you have a weak one... or really aren't sure.
I am sure there is a break somewhere. When I first started the motor after putting on the valley pan I got a decent shock from the distributor. While checking the wires with it running, I got it two more times. Boo! All at the cap.
 
NAPA also jacked me around on a wheel hub that wasn't right. I left for a couple years, but they have parts I can't get anywhere else.
FYI if you ask them for the Independent Trucker Discount it usually knocks off double digit percent off the invoice.
America's Independent Truckers' Association - Information
I never used NAPA in Bakersfield. They were/are there, but I always went with Car Quest. But they are not here in Chico.
 
I am sure there is a break somewhere. When I first started the motor after putting on the valley pan I got a decent shock from the distributor. While checking the wires with it running, I got it two more times. Boo! All at the cap.
Thats as good a sign as any... most would have given up before 3 times...:poke:, I would call it tenacity...
 
Thats as good a sign as any... most would have given up before 3 times...:poke:, I would call it tenacity...
You ought to hear my story about the guy breaking into my garage. I went out there three times before my brain screamed at me, "Hey idiot - there's a guy in the garage!!!" He was in there all the while. D'oh! Some times I'm slow.
 
Well, yesterday I found a set of wires at Pep Boys - and only 20 bucks! NAPA never called me back.

While installing them I found the source of my shock - one of the cups on the cap was very loose; I could almost blow it off with my mouth. I was encouraged as I thought that might eb the source of te intermittent misfire.

It wasn't. Put the new set on and have the same condition.

So now I'm baffled. All were firing great before I swapped that valley pan. Now, not. I'm thinking either I inadvertently screwed up a gasket so it's covering an intake, or I need to take it all off and put on a stock pan. The one I installed has the heat crossovers plugged. (Trying to stop carb boiling after a long drive.) While talking with my buddy "Big Chris" Fredricksen yesterday about another vehicle, I mentioned this problem. He told me there is a possibility my choke would never open since I've blocked off those crossover ports. Anyone else have this problem? Could it be a closed choke causing this? The car idles fine, on all 8. Even fires on all 8 if I accelerate slowly. But, if I hit the pedal at all it goes to 7. It's frustrating.
 
You could have a slight vacuum leak. When running on the accelerator pump shot it masks it?
From here I would think it should have a miss at idle.
On the choke thing it might not open as quick but it will open (IMO).
Should be simple to pull the air cleaner off and find out.
 
Back
Top