I had the engine apart and it had a stock type timing set so I just to be "making it better" swapped in a double roller set and put it in the 4 degrees advanced slot. Keep in mind that it was a running engine and nothing else changed. Put the engine back together, stabbed in the distributor, turned it to around the right place and the engine fired up. But it has a hard miss in one cylinder. The plugs are new, the ignition wires are new, every other cylinder runs just fine, just not the "missing" one. It is not carburetion either.

My fear is by advancing the camshaft I messed up the rotor phasing. I'd hate to have to pull it down to change the timing set.

Any suggestions? I do have an extra distributor cap into which to drill a hole.

R.

Is the firing order correct? Did you check the timing? Assuming you installed the timing set properly its one of these. If you put the distributor back in the same location as before the timing is likely off.

If its not firing order or timing you goofed something with the timing chain install. 4 degrees shouldn't make the engine miss, but you could have read the marks on the adjustable crank sprocket wrong.

EDIT: I see you did not check the timing. I can almost guarantee with 99% certainty you need to adjust the timing.

Advancing gives less valve to piston clearance. Could be a bent valve? Check the compression.....
Normally a stock 400 should tolerate anything here.... But you did not tell about the internals in this engine. Hope it is nothing serious.

Forgot one thing which is more likely: The cam has moved axially, and one of the lobes hit and lift on the wrong lifter. That could happen, and has happened, although not very often on Mopars. Easiest is to pull the intake, valley pan and look for it. My

Thanks for the responses. Here are some clarifications:

0. I live 600 miles away from the truck, am trying to get it to run so my wife can have something to haul dirt.

1. The engine starts and runs just fine, except for the consistent miss on the one cylinder. I am bringing a timing light with me on my next visit to make sure the timing is closer than in the ballpark, but i'm sure it's within 10 degrees of where it's supposed to be.

2. The engine is very low compression with a stock cam and there's no way a valve hit a piston.

3. The engine was disassembled in a hurry. I was trying to change head gaskets and clutch on a long weekend. I ended up taking the engine out due to some problems with the bellhousing. Also, the engine had to be turned over a few times to get bolts accessible. I know how to put a distributor into an engine that has been completely apart.

I will try to be honest and tell you what the problem really is when I find it. In the mean time, keep those ideas coming!

R

might want to pull the dizzy and see if any of the reluctor fins are broken off.....this happened to me on a brand new MSD unit...one cylinder was dead cold....????

Rickster

Keeping this thread alive...I was at the house for a week and didn't lay a hand on the engine. Too long a list of things to do before my daughter's wedding.
Thanks for the input. The distributor is the same one I took out.
R.

Did you try a compression test on the one cylinder or check the plug or wire?