1989 740 B200E - UK

Hi Everybody

Have a niggling issue with our UK 1989 740 2.0ltr Auto(B200E engine). Need some help please.

For years now the car had a slight tendancy to fire up on 3 cylinders (sometimes 4 with a bit of a missfire on the 4th pot) which cleared ok by blipping the throttle. A few months ago this got heaps worse and would not just dissappear by blipping the throttle.

Car has been religiously serviced and maintained to a high standard from new. Replaced plugs - genuine Volvo/Bosche, nope. Replaced king and HT leads - one HT lead connection to the plug looked yucky - but nope. Replaced the Distributor cap and Rotor arm (halfords own) and bingo all seemed nuch better (actually this was hardly surprising as the car was then still on its origonal Dist cap and rotor arm !)

That was 4 months ago in Oct 04. 2 weeks ago the firing on 3 started again - Grrrrrrrrrrrrrr. Now we have been having some pretty damp weather so will spray leads, king lead, coil, distributor cap etc with copious volumes of WD40 and see what happens Wed morning - might drop lucky. Bye the way all leads are sitting well on plugs, in dist cap etc.

Has anyone else experienced this. Please share experiences and what U did to resolve.

Many thanks.

Andy

Assuming you have good compression, one thing you seem to have missed is injector seals. If that doesn't fix the problem, see if you can find out which cylinder is not firing. Then swap injectors from that cylinder to another and see if the problem follows the injector.

Hi Mike

Compression has not been tested but will look at if easier thing (that I can do) fail to resolve. Car is fine after 30 seconds to 1 minute i.e. when engine starts to warm up (which possibly points to damp ??).

I do not know which of the cylinders is not firing. Difficult to locate as I have only a few seconds to locate. I can only try over a few days first thing in the morning unless you have any other ideas - very welcome.

Had thought trying fuel injector cleaner but my experience of this historically is that it is waste of good money.

Had thought of injector seals and when Son returns with car this evening it is on my list to spray them with aWD40 and see if we have any leaks there. I have experienced the seals getting hard and leaking before and on other

Have also considered a leaking inlet manifold gasket but don't think it is that - nothing obviously loose or leaking noises.

Andy

Either leaking injector seals (idle would be slighly "loppy" most of the time), or more likely, a leaking injector flooding the offending cylinder whilst the engine is stopped.

Tim..

On the list, not thought of that one.

Andy

I had a misfire at idle a while go. I too thought it was ignition related and replaced all the HT electrics. Turned out to be the inlet manifold gasket was leaking. This sort of problem tends to be more obvious at low rpm - at higher speeds a small air leak is less significant.

Get a squeezy bottle and with the engine running, squirt water over the inlet tract. Include the injector seats, the manifold union, and any hose connections. Avoid getting the ignition components wet. If the engine note changes, or it stalls, you have a leak.

I also has a bad misfire shortly after cleaning the car once - water had got to the inside of the distributor. Removing it and applying WD40 solved this. But it would be unlikely to be a recurring problem once it has dried out, unless the cap is damaged.