1989 300 SE
160 K MILES
just purchased this unit . I am experiencing a hard start . I would expect a turn of the key and start. Yet this is a long sustained crank and slowly it catches ( MAYBE ) . Then another long crank and slowly it starts to catch- start to feather the gas and pamper it for a few minutes.

Any suggestions on where to start?

thanks

Check to see that the fuel accumulator is holding fuel pressure. A worn accumulator will make the engine very hard to start when the engine is warm. Worn fuel injectors that leak fuel down into the cylinder will also allow for a hard start condition. A faulty fuel pressure regulator can cause these symptoms so check to make sure that you are getting adequate fuel pressure. What is the state of tune of the engine? Worn ignition components such as wires, plugs and cap & rotor are a good baseline to check out.

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1989 300CE

Thanks
I wasnt thinking - PLUGS WIRE DISTRIBUTOR CAP REPLACED 6 MONTHS AGO
ENGINE IS OK AFTER WARMED UP

It is the initial start up that is problematic

I would start off by checking the fuel pressure. I had similar problems with my 300CE. The fuel pressure regulator ended up being the culprit. I also had a small fuel leak from the EHA valve. After replacing both of these parts it felt like a completely new car. When was the fuel filter last changed? Mine looked quite old when it was changed out last year and I wouldn't doubt that it was partially obstructed from many years of service. Always start off with the simple things and then work up.

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1989 300CE

Check your O.V.P. (Over Voltage protection) relay.,

It provides voltage for the cold start relay + other things.

Also check the operation of your Fuel Pump Relay.

thanks guys
best resource for a manual on this unit

all these parts names - not sure where they are

Is there a club for this problem?

Our 88' 300SEL started doing this suddenly last Friday... ran fine until I filled with gas and then it would not start. Had it towed home. Finally got it started 2 days later, but hard to start and is misses, sputters then it stalls again. Have already checked the fuel pump relay, checked for spark, plugs, replaced dist rotor, etc.

Still have not figured it out.

BTW, ours also has 160K miles.

yikes !
I was hoping to go on a road trip this week - close to 1000 mile round trip
- maybe not such a good idea
accumulators, pressure regulators
relays

sounds like a couple of Saturdays ......under the hood and scratching my head