|
A lot of the basics are covered. My first thought was a plugged cat, but of course there isn't one.
I presume a good strong spark has been confirmed against the block in dim lighting and that the distributor cap/points look okay, also the timing advances okay. Weak coils aren't common, but at that age anything is possible.
I was thinking more along the lines of Phil, fuel starvation and the fuel distributor suffering from gas varnish buildup likely there after sitting for so many years. Easy of course is to start with Phil's advice, checking the plate for easy, smooth movement, a bit of bounce from a high drop, still being centred in the throat and the axle not being worn enough to wiggle side-to-side and able to bind in the throat. My real thought would be deposits in the distributor ports restricting fuel flow and perhaps also needing the mix adjusted to current conditions.
One of our K-Jet experts like Art will likely soon trip over this to add their wisdom. In the meantime, perhaps check out videos on K-Jet fuel distributor rebuild for clues and to see how the guts work. I see a few of those online.
Now if it was only a minor problem I might suggest starting with a high quality fuel injection gas additive to see if that starts to make a difference, but yours isn't really drivable and likely quite beyond such a gradual cleaning.
The K-Jet fuel distributor in my '74 144GL was extremely reliable, only needing adjustment once or twice in its life and twice the injectors needed new seals, but that was at age 15 when I sold it, not 49. Wow, I'm impressed and surprised it hasn't rusted out long ago; Must have been garaged and well taken care of. I did find my city driven engine (with lots of crawling in rush hour) enjoyed a regular high rev Italian tune-up on the highway as well as premium gas and occasional gas additive. Still got a full bottle of that additive hiding somewhere in a box and knowing me at the time, probably a noname brand.
Thinking of other fuel starvation possibilities, you've got good fuel pressure and an easy start, but do consider a worn fuel pump not being able to keep up with demand or fuel delivery being restricted somewhere (other than the filter you replaced). Verify that both the main and in-tank pump are running and the main pump sounds normal. If you're suspicious, you could check timed fuel delivery volume to the engine into a measured jar. There's a spec somewhere. You could also check the amp draw through the main pump after it's been running a bit and become fairly warm. As I recall, 9-10 amps is good and anything close to 14 amps says it's significantly worn and working too hard. I'll also mention that if the in-tank pump had been replaced, it's easy to wire it backwards and cause fuel delivery problems with extremely poor acceleration, hesitation and stumbling like there's a governor. Art maintains it won't run in reverse when wired backwards, but for whatver reason I did have major problems with such symptoms when I once wired it backwards, instantly fixed when wired correctly.
I'm also wondering what the gas tank looks like inside. Gunk or rust flakes could be partially blocking the pickup tube. I believe there's a drain plug on the bottom of your tank. Maybe worth draining a little off to see how bad it is at the bottom.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
