Well, my '71 FJ40 isn't!

'77 or '78 2F engine, non-USA vacuum advance distributor, non-USA carburetor.

Last month I finished my power steering and front disc brake conversions, and installed the non-USA distributor (still had the stock F engine 2 bbl. carburetor). Ran fine, except the same problem came back that I've had for about a year, each time I filled the tank the vehicle would miss and hesitate badly, especially after hard cornering or a hard pull uphill. After a few days it would run OK. I've checked the gas tank, lines, fuel filter, and fuel pump, everything seems to be fine. Then I noticed unburnt fuel in the exhaust and black buildup (excess fuel?) in the carburetor throttle bores and figured it could be a carburetor problem, so I installed the like-new non-USA carburetor and adjusted the float so the fuel level is halfway up in the sight glass like it should be.

This weekend (after not being driven for a couple of weeks) it was extremely hard to start, I finally got it going and noticed a lot of unburnt fuel in the exhaust. I set the point gap with my dwell meter to 41 degrees, set the timing to 7 degrees BTDC, and adjusted the idle mixture/idle speed - it seemed to run OK at idle, but a little rough.

When I took it around the block it had a total lack of power, so I decided to put my timing light on the other cylinder's plug wires to see if I was getting spark - #1 has a consistent and strong spark, same with #6 - intermittent/inconsistent on #2 - nothing at all on #3 - every once in a while on #4 - nothing at all on #5. I also double-checked by pulling the plug wires one at a time to see if the engine ran different, same result. I installed a new distributor cap, rotor, and plug wires - no change. I also removed the distributor cap to check the funtion of the points - everything appears normal.

Am I missing something? Could a problem with the coil be causing this? Why would it be consistently firing on #1 and #6, but not the other cylinders?

Please help!!! I can't go on like this any longer. I have a few days this week to work on this over the holiday, any tips/suggestions/comments would be appreciated!

Thanks.

John

G'day
It is really hard to diagnose a fault unless you are there but I will help where I can, first is the full tank issue, could be the carbon cannister or tank vent line filling with fuel and filling the inlet with fuel. Next, don't rely on a timing light to give you accurate results for reliable spark, with the engine running disconnect a lead and put a screw driver in and check the size/consistancy of the spark.
At least 10mm +. Hold the screwdriver at the end of the handle so it won't shock you. A coil can't cause a fault like that.
Check all leads for spark and check your tank vent tubes for fuel.
let me know.

Thanks for the tips, I'll check it out after work this evening and let you know what I find.