280i engine rough as rats - any suggestions?

[jchase]

Well, its MOT time and I've reassembled the collection of bits to make a car. But the engine is now running as rough as rats.

It used to be fine, before being laid up, and now it is hard to start, runs for a few seconds and dies when cold. Once warm, it is difficult to rev it up, it seems to bog down, then occasionaly backfires. I've been through the wedge bible, the Granda 2.8i Haynes and the Capri 2.8i Haynes, and they can only suggest checking the fuel pump wiring ,or use injector cleaner.

I thought I'd see if there was a common problem that you guys (and gals) may know of ? The MOT is Tuesday... argghh.

-jim

[wedg1e]

Been a while since I worked on a 280, but here goes...

Take the air filter box and air filter off. Turn the ignition on, poke your hand into the air filter box and lift the circular metering flap. The fuel pump should start. You should be able to lift the flap through its range of travel wih 'some', but not a lot of, resistance. It should then return to rest equally smoothly. If it sticks, or there's no resistance at all, there's something wrong with the fuel metering head or fuel delivery system. For you to get it start at all implies the pump is running, since the K-Jetronic injectors work solely on the pressure of the fuel. However, there are a couple of devices which modofy the fuel delivery during warm-up: the auxiliary air valve and the warmup regulator are notorious for causing problems, especially after layups.

Ian

[jchase]

Hmmm,

I put in some injector cleaner, which seems to have helped a little, with hot engine, she no longer backfires on rapid pressing of the throttle, and she is actually driveable now without stalling.

I removed the air box, and the top air hose and checked for free play of the disc - all okay, but I noticed a small puddle of fuel in the air box, below the metering unit, so I guess the metering unit is faulty, plus more than likely the cold enrichment bit.

Anyone got a spare for sale?

-Jim

[adam quantrill]

Hey Jim - if you wanna borrow the CO meter give me a bell. Might help with the diagnosis - if it's runnung far too rich any engine will run funny.

I won't need it for another year - Fat Bob gave me my green A5 bit of paper - he let me off my dim headlights!

[adam quantrill]

Hey Jim - if you wanna borrow the CO meter give me a bell. Might help with the diagnosis - if it's running far too rich any engine will run funny.

I won't need it for another year - Fat Bob gave me my green A5 bit of paper - he let me off my dim headlights!