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Hello all,

I've read a handful of posts on the W124 hard start, low rpm idle & stalling but could use some additional help. Fuel pumps & lines have been replaced as have the Engine Control Module and a handful of other small, accessible electrical items. Also seems to run rich.

First, can anyone recommend a knowledgeable, practical mechanic in the Albany-NYC corridor or NY/NJ/CT area? I brought the car to a specialist shop specifically for this issue. They called me back a handful of days later and said the car needs about $8,000 of suspension work. NOT what brought the car in for! I know it needs that work as well. But that's irrelevant if I can't get it started, and it stalls out a traffic lights & left turn lanes (scary!) even after it's been running for a while at 2000-3500 rpm.

They're encouraging me to give up & junk the car but I think at ~160K miles, it's got a lot of life left, and I'd like to take care of it.

Resources & recomendations welcome!

Thanks - Mark
 

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I second the disbelief regarding the $8k in suspension work. Sounds like they wan to replace *everything* LOL. I'm sure a big part of it is the hydraulic cylinders and accumulators for the self-leveling rear suspension.

The fuel system on these cars can be a real pain to diagnose. You need to be able to measure the upper and lower chamber fuel pressures at the fuel distributor. It's absolutely critical. As is setting the duty cycle of the EHA valve (electro-hydraulic actuator) which is held to the back of the fuel distributor by two screws. If that EHA valve shows any signs of leaking from the plastic body it's a goner and not cheap to replace. The fuel distributor is an extremely precision device with fuel passages smaller in diameter than a human hair. If a Benz with the CIS-E fuel system sits for a long time or is driven infrequently - watch out. It'll have problems, especially when run on fuel that contains ethanol.

You may want to check operation of the idle control valve which is on top of the intake manifold ahead of the fuel distributor/air inlet housing. The idle control valve has a two pin connector that you can disconnect/connect with the engine running. Idle speed should change when you do that. In fact the engine will probably stall when you disconnect the valve. If it doesn't the valve may be sticking.

Good luck. I've been working on these cars for over 20 years and fuel system problems are a real PITA to diagnose.
 

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I'm reminded of the cartoon that shows the guy with HFM hooked up to a diagnostic reader......while the guy with CIS-E has a hammer hovering over the FD.

I actually found a kind of flow chart for the CIS system.....at least it gives you some starting points. I think it was for a Porsche and/or a VW. Same principle as our cars. HD is fully capable of making a flow chart for this system, but doesn't want to...which is his prerogative.

What makes it so complicated is that it's mostly a mechanical system and the mechanical parts wear all over the system with mileage causing confusion, because you can't see the wear just by looking at things.

Kevin
 

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my CIS 300E2.6 suffered with random stalls when you gave it gas after a full stop, turned out to be the injector seals, and 2 of hte 6 injectors were in poor shape too, so we replaced all 6 and its run like a new car ever since. this is after I spent nearly 2 years trying everything else I could think of. I found a lot of things that were 'wrong' and needed replacing, like teh airflow potentiometer on the side of the air flow meter, the EHA, etc etc. each of those things would make it run 'better' but it still stalled until we fixed the injector seals.
 
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