Lately my '86 has started what sounds like chugging or missing at rpms over 3000. I just swapped plugs and the 1 and 6 were mat black, while 2 thru 5 were fine. Idles smooth, timing is just a tick ahead of ten (per a seasoned Mopar mechanic) Any suggestions?

Back story: '86 Ram D100 with what I am finding out to be a pieced together 1 bbl 225. I do occasionally have a sticky lifter, but it unsticks after a minute or two.

I forgot to mention, it does not always do this. Earlier today it was running awsome at speed. Went to work for 4 hours, came out and it was chugging again.

You have a tough one. Intermittent stuff is a bear.

What 1 bbl are you running? Engine temperature?

Being intermittent, fuel delivery, or an issue with the EGR maybe.

Is it like a lean surge at cruise? (If you mash the throttle to the floor, does it go away for a bit?)

CJ

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Part of Tyrde-Browne Racing

What 1 bbl are you running? Engine temperature?

Being intermittent, fuel delivery, or an issue with the EGR maybe.



I assume I am running a stock 1945 holley. Temp seems just fine, although when it is cold (-0 and lower) it has a tendency to do it more often.

Is this Detonation? Or Pinging? I had this problem when I went to a super six on my 87. I bought a NOS carb from Dan and it fixed the problem.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Could it be the sticky lifter not completely unsticking just sort of doing its job?

and Cuda, how did the super six improve your 87?

Is this '86 Lean Burn equipped? Does it have a regular #1945 or a feedback #6145 (with oxygen sensor in the exhaust manifold collector)?

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Too many people who were born on third base actually believe they've hit a triple.

Per the FSM, looks like it is NOT the feedback, definitely a 1945.

http://photos-d.ak.fbcdn.net/photos-ak-snc1/v2681/14/54/1024195730/n1024195730_30349235_2777425.jpg

I'd swap out the coil-to-dist ignition wire; I've had ones that caused problems like that intermittently even though they tested OK at other times; then I'd swap coils if it has more than 100K miles.

I'll give it a try and post if it helps.

FYI- I had an intermittant hydraulic lifter type noise on my original engine that turned out to be a badly worn rocker arm.

15MPG over a Shot nonfunctional Lean Burn system...About 22 to 25 Mpg Hwy at 55. With the rear end in the truck anything over that and the mileage really drops.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

66acuda-

auto or 4 spd?

904 Auto not the 727
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered