I've recently overhauled the top end of the engine compartment of my 1990 190e 2.6. I picked it up as a project car. It was barely running and smoking when I bought it, but the body and interior are in great shape. I've been restoring it's mechanical condition. I started with a valve job, which went rather well. It had a cracked valve and lot's of "I don't change my oil" sludge build up. I have close to 10k miles on the rebuild now and some things are still lingering. I replaced the timing chain and cam gear while I had it all apart and am not entirely certain that I installed them correctly.

I don't know how this car is supposed to run as I have not driven one that is running properly. However, since I put this scrap heap back in to the likings of a vehicle, it has started poorly. It starts, jumps up to 1500 rpm then bucks and kicks at 500 rpm for a few seconds then smoothes right out. Obviously this is not an internal engine issue, so I have been living with it for some time. Under heavy acceleration and higher RPM it runs very smooth, but I can tell it's lacking it's potential power.

I replaced the fuel pressure regulator and the fuel pumps & filter and adjusted the mixture for optimum results.

I know there's a cold start valve, but am not sure how to check if it's working.

I'm starting to think I may have put the timing chain together one tooth off. When I shut the engine off, the slack of the timing chain is on the drivers side opposite of the tensioner. I didn't note which side had slack when I originally disassembled it.

Also note: I am suffering with really slow acceleration when the AC is on. With the accelerator to the floor, I can count to 4 sometimes 5 before hitting 10 miles per hour in heavy summer traffic.

Is there an easy way to check the timing chain installation and the cold start valve?

Thanks!

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1990 190e 2.6 (About to have a Kompressor )