volvo 240 rough running

Hi there, wondering if anyone can give some advice?

I've a '88 Volvo 240 GL, 90K on the clock, which recently started
running really rough. It sounds really noisy, and hardly acelerates,
even with the gas pedal/accelerator pressed all the way down.

It idles very roughly, at about 400/500 rpm, but doensn't stall.

There doesn't appear to be an Air Mass Meter, so I'm assuming this is
an early type of fuel injection, the K-Jetronic, for example?

Sounds like it isn't firing on all four cylinders, (would that also
cause the severe degradation in acceleration?).

-Douglas

 

If this car has K-Jet (still amazes me they used that old system so long
over there) then the first thing I'd do is check very carefully for vacuum
leaks.

 

I'm pretty sure that it will be K-Jet; I think it was a couple of
years later that we finally moved on. It may have been old, but it was
extremely reliable and durable. I'm surprised that carb. models were
still available alongside K-Jet.

Certainly check for air leaks, including the injector seals (squirt a
little water over the injector seats while the engine is running - if
it gets drawn in, the engine will falter or stall) and the pipes that
go to the auxiliary air valve (sits on the side of the valve cover on
the top of the engine), and make sure that the fat rubber boot under
the inlet manifold is still properly in place between the throttle
body and the air flow meter. Also squirt a little water around the
inlet manifold gasket.

But I would start with checking the ignition componets, particularly
the distributor cap and rotor arm. If you have access to a timing
light or spark tester, make sure you are getting a healthy spark to
all four cylinders.

When you say it sounds really noisy, where from? What sort of noise?

Does the problem change as the engine warms up?
--

Stewart Hargrave


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I had a friend round today, and tried starting it up again. There was
definately unburnt fuel vapour being blown out of the exhaust. The
contacts inside the distributor cap were green (copper oxidation?), so
cleaned them off, cleaned the HT leads, and checked for corrosion at
the spark plug and distributor ends. It ran ok when restarted, but
reverted back to it's misfiring at 500rpm after about 30 seconds.

Pretty sure it's an electrical problem now, when it is light again
outside, I'll check again further.

The engine. It was consistent with misfiring.

When I had the problem the other day, it carried on until I was able
to get the car home, and the engine was up to temperature.

Thanks all for the advice so far!

-Douglas