Engine "Popped" at cold start and now it has a miss...UPDATE!!!

[Mfr426]

Hey folks, just got my 383 finally running like a top! It has been on the road for about a month. Today I go out to start her up (cold) and hear a pop POP POP coming from what seemed to be number 6 or 8 cylinder? It was fairly loud (but I was in the garage and it does echo). I quickly turned it off and then fired it back up. It did it a few more times. I checked and my oil pressure was great? The popping went away after about 20 of "them" but now my car has a miss and does not idle smoothly? It now has a rough idle and misses on acceleration?

I checked the plugs and all had normal color. Number 6 had some slight carbon build up but nothing that I would consider excessive. I checked timing and it was right at 10 degrees where it's been for ages. The car drives like crap too and you can feel the buck, buck, buck when you try to accelerate?

I cleaned all plugs, checked the cap and rotor and all the obvious things and nothing seems out of whack? Any of your old motor heads care to take a stab at what is going on? I finally got this motor running like an ape and this happens. I give up!

On the ledge is...

Mike R in Reading PA

[69BlackChargerRT]

I had a similar problem and it turned out to be that the header had melted some of the plug boot and in turn wasn't making a good contact.  I replaced the boot and the problem was solved.  Just a thought!

[Mfr426]

Interesting. I'm going to be checking the wires (again) tomorrow

[dodge freak]

I believe you have check your plugs many times now and one of the spark plug wires may have been damage. It does not take much on some of them. You need to check each one with a ohm meter. How could you tell which cylinder it was?? I would look for a bad wire, why it went out like that not to sure but it does get hot after you shut it off in a garage.When you check them move them around by each ends. If they all seem good might as well do another compression test to check for a bad valve. Your brand new carb should still be fine, a holley may have blown a power valve but not with a eddy.

[Mfr426]

I'm going to pull each wire off till I find one that has no effect on how the motor runs. Then I'll swap out a good wire for that wire and see if that's the case. The wire set that I have is one of the date coded OEM style.

I'm hoping that I find a bad wire. The compression test and bad valve, bent pushrod, etc. woiuld send me to the psycho ward...

[7273chargerguy]

if you have a tach hooked up make sure the wire is'nt touching a header or anything. i had that same problem my tach was shorting out and stealing all the spark.

[SirNik73]

as said before I've had this problem due to melted spark plug wires. if that is what yoru problem is, i installed some fiberglass heat sheilds. they work good. i got mine from summit, but their website sucks for links... these are what i'm talking about.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33692&item=8045745561

[Mfr426]

How about (2) bent pushrods? Yep...number one intake and exhaust was bent to hell. No other damage. Someone forgot to put a spacer in the rocker arm (not me).

I have a new set on the way.

[Mfr426]

OK folks, I figured out what went wrong here. When I got the new pushrods and went to put them in the number 1 pushrods were loose even after I torqued the rocker arms. Here it turns out that the lifters failed causing the rods to bent.

So, I have (2) bad lifters. I'm searching for replacements today so I can enjoy the car over this long holiday weekend. These were MP lifters from a Purple Shaft cam kit. The car has about 150 miles on it too so the lesson learned is that these thing DO fail on occasion.

Thanks for all the help guys!

Mike R

[greenpigs]

I have heard of failing lifters to often, on my next rebuild I am going with a solid lifter cam.

[Mfr426]

I agree. After this mess I've learned a valuable lesson.

[hemi32]

Check out the article on pg 124 of the June issue of Hot Rod magazine. It's titled "When Good Cams Go Bad" but it also covers issues with lifters today that were not seen in the past - poor quality due to inferior offshore supplied lifters.

[Mfr426]

I got sealed power replacement lifters today at Advance. Those guys are amazing!!! Anyway, I did notice that they said "Made in the USA" which I prefer. We'lll see tomorrow how she runs after I let the RTV for the valve covers cure.

My fingers are crossed.

[firefighter3931]

Remember to treat this like a routine breakin....2000-2500 rpm for at least 20 minutes. You don't want to wipe that lobe on the cam. Hopefully you coated the face of that lifter with some moly lube....

Ron