Hi All,

looking for some advice re an engine problem that developed literally over night.

Got a 1988 245DL wagon that's been driving fine for the last two years, pretty much smooth as silk. Noticed a little rough running recently in cold/damp but it was only when I put the foot down aggressively and only lasted until I lifted my foot and accelerated normally. It went away after a couple of minutes running.

I got home last night just fine, woke up this morning and started the car. It started perfectly normally and then died immediately. I turned it over again and again, normal start but died immediately.

Sitting in the driveway it won't idle with my foot off the pedal. If I lay my foot down a little and hold it it'll idle very roughly, then almost die, give a little pop (like a backfire) and accelerate smoothly and normally only to run down to idle and repeat the whole thing over again. If I pump my foot it'll maintain revs for a short while longer and then die to the rough idle again, occasionally it'll accelerate smoothly and normally again only to die.

I checked the pump fuses. The pump itself I can hear whirring away in the background as usual. I haven't been able to check the fuel filter yet but I figure if it'll rev up smoothly every few seconds it must be getting occasional bursts of fuel, not an overall restricted flow. The air filter is fairly new and as far as I can tell all the intake hoses are kosher.

Been looking for the cold start valve and can't find it. Haynes sucks!

Has anyone got any clues/suggestions?

Many thanks,

Ben

Is it running to lean or to rich ? any black smoke from exhaust ?

I have no idea how to find out if it is or not. No black smoke, but seems as though there may be a lot of water vapour in the exhaust. Lots of white 'smoke'. No smell of fuel though and it's kinda funny how it'll pop or backfire and that somehow allows it to rev normally for a few seconds. I've checked everything I can think of as far as my meagre skills will allow but my Haynes manual, waste of shelf space that it is, doesn't even list what each of the various hoses on the fuel rail and throttle body actually are. Go figure!

No cold start valve on a 88. Unplug the air mass meter with the key off and see if it runs any better. Its possible the idle air control valve is not working correctly, you can disconnect the air hose on the engine side, allowing air in past the closed throttle plate - if it begans to idle high that would suggest a bad valve.

Backfires are usually problems with the ignition ...

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Thanks for that, I'll give it a shot and see what happens. I wondered where the cold start valve was! It was driving me nuts trying to find it.