Two months ago on a long trip, the 244 DL lost power, then died on the highway. Would crank but not run. Mechanic checked the fuel filter and pump - both OK. Then he stuck an allen wrench in the hole on the fuel distributor and adjusted the plate inside, and it was fine. Easy enough.

Fine for another few thousand miles, we once again sputter and die, again will crank but not start. Got out the allen wrench and turned away, but this time it did no good. Finally I turned so far something (probably that plate) came loose - I heard something drop. Now when I stick the allen wrench in, there's nothing to turn.

From what I've read, that plate, which rises as air comes in from below and lets more fuel in, may be stuck, may need adjustment, or may not be centered in the air venturi.

Two questions:

1) Is there any way to isolate the problem at the fuel distributor? (ie., would it work to unhook the fuel line to the distributor, crank the engine and hope fuel comes out, then check to see if fuel is not reaching the injectors, thereby isolating the problem at the distributor?)
2) Assuming it is the fuel distributor, how do I get in there to check out the plate (also heard it described as plunger) to make sure it is centered and not stuck? Is this a job for a not-very-handy guy like me. It may not be worth it to get the Volvo towed and fixed.

Thanks

The mechanic set the fuel/air mixture. As the diagram in the other message indicates, it's a rough adjustment for CO levels. The diagram shows a roller on which the plunger sits. The plunger moves up and down to determine the amount of fuel passing through metered slots to the injectors. The screw you turned adjusts the movement of the arm relative to movement of the sensor plate. When the sensor plate moves up, so does the plunger to allow more gas in as more air enters.

If you're going to mess around with air/fuel system (distributor air flow) it will be easier to take the entire assemby out. I've not turned the screw far enough to cause a problem, but I guess it is possible. If it has been turned too far, you probably will have to take everything off. A Haynes Manual gives pretty good information.

If you remove it be careful. The entire assembly comes out without much problem, except I had to lossen bolts, remove bolts to move the power steering pump aside (forward) to have room to get it out. There's a stud on the back near the firewall that you can't see and it's hard to feel.

Once the assembly is out, be careful taking off the distributor. The plunger will fall out if you're not careful, and if it is damaged you willl need to replace the whole distributor, which is expensive. The best price I've seen for a reman is about $500 (except for a guy who gave me a deal). When you clean the plunger, don't scrape it with anything metal, and when you have it clean, don't wipe it - use air to dry it. The tolerances are pretty small and some lint can apparently screw averything up.

Whe you reassemble, it's best to use new o-rings and, if you can, new copper seal washes on the banjo fittings.

All that said, my guess is that the mechanic just made a temporary, lazy repair.

It ain't that bad, but you gotta be careful. Take your time. Haste doesn't only make waste, it fouls up cars.

Good luck.

Jim Hampton

Sorry I forgot to attach the pix.

It may be that the fuel pressure was rising due to a blockage of the return line or a plugging fuel pressure regulator. Ironically, on the K-jet, an increase in fuel pressure will reduce the flow to the injectors.

That mechanic probably made a temporary adjustment that compensated for fuel pressure error. Think of it as compensating errors -- he enriched the mixture (beyond where it should have normally been) to offset the leaned-out condition from the blockage.

That adjustment screw changes the height of a pivot point. You might be able to see it on the diagram below -- the screw is item #7.

On the later versions of K-jet, the fuel pressure regulator is on the side of the fuel distributor. You are fortunate -- '75 is the ONLY year that the fuel distributor is easily accessible. But to work on your car you really should have the service literature.


Don Foster (near Cape Cod, MA)