Car: 1991 560 SEL, 103500 miles
Problem: hard to start

It does not matter what time of the day is, it always take me three turns to get the car started. On first try, the engine will be on for 1 second and die. On second one, only starter will turn but the engine will not even catch. On the third turn, it will come on but only at 300 to 400 rpm for 10 second. At this time, I would step on gas and everything will be fine from there on. I know the plug wire, rotor, cap are all new. I will pull a plug out tomorrow to check the condition. What else should I check?

It will start right up within 5 minutes of turning engine off. If I park the car for 1 hour, it will again take me three tries to get it started. I know it takes air/spark/fuel/compression to get a car started but I need tips for a step by step diagnostic.

many thanks in advance.

Bad accumulator, next to the fuel filter or the pressure regulator. Pressure bleeds off and makes it hard to start.

This can be checked by monitoring fuel pressure --it should stay up quite a while if not indefinitely with the engine off. If it drops in 30 min or so, you need to either replace the fuel pressure regulator next to the fuel distributor of the accumulator.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter, thanks for coming to the rescue again. How do I "monitoring fuel pressure"? Will change fuel filter help? Since I don't have service record on this car, I am thinking about changing the fuel filter. It is the last filter I have not changed since purchase.

BTW, what size socket should I use to take out the spark plug?

It sounds like fuel pressure is bleeding off and allowing vapor to form in the fuel lines.

Possible causes are leaky fuel pressure regulator, bad fuel pressure accumulator, or a leaky check valve in the fuel pump outlet fitting.

Hi, Kebowers. You are not suggesting that I need to replace all of them, right?

Based on what I read from a search, I would go to dealer next week to do a fuel pressure check. Will appreciate any tips on how to intepret the data?

My search on the "fuel pump relay" found this statement from you: (check for fuel leaks on the "bleed line" of the regulator -- if there is fuel in there, replace). Which one is the bleed line?

I think he means the "vent line" - the 4 mm off white nylon tubing that routes to the PCV system.

If this line has liquid fuel in it, the regulator is leaking and needs to be replaced.

Duke