no fuel supply at cylinder 7 and 8

[ThomasH]

we have a 440 with mopar cast iron intake and edelbrock 650 cfm.
all spark plugs working well.
cylinders 1 to 6 burning fuel very well.
at cylinder 7 and 8 we have no fuel.
spark plugs are try and do not have smell or petrol or residus.

any ideas where the error is?

[slotcarone]

Does it run well when cold with the choke still on? Have you checked the compression in those cylinders?

[ThomasH]

runs a little rough when cold.
compression not checked yet.

[slotcarone]

So the car is running on 6 cylinders? Must be very rough. Was the car running fine and then all of a sudden it is not? More info is needed to help you out here.

[ThomasH]

engine was sitting some ten years.
fitted new carburator and ignition before first run.
fired up right away.
ignition ajusted and run for a few minutes.
seams to run smooth.
next run to issue come up.
we could clearly hear the engine running only on six cylinders.
a little rough, but not very much.

[slotcarone]

Was it sitting after a rebuild? If not this is very unusual. Have you driven the car? Maybe it will correct itself. Any popping out the intake or exhaust?

[Steve Payne]

Maybe you have some sticky valves or stuck piston rings?
As has been said do a compression test.
Once running if you pull those 2 HT leads off at the distributor does it make a difference?
If something is sticking a few heat cycles might see things free off as long as nothing is damaged.

Steve

[Wolfgang]

if you have use an endoscope to check the cylinders. compression test as mentioned. Once had a customer with a Corvette C3, he demounted the carb himself and 'sealed' the intakes with paper tissues! in order to prevent dust and dirt to enter during the refurbishment. Then remounted the carb without taking the tissues out. In any way he got the engine running but with similar effect like on your car...
At the end he went to my garage because engine running rough, we checked the intake (also with endoscope) and puzzled out the remaining rest of the tissues. After some miles the car was running normal - customer didn't show up again with this issue, so seems we got it solved.

[ThomasH]

Finally it turned out to bei a too much lean carburator.
Thank you all

[Martin R]

Good result