Hiya,
My '76 245dl does the following: on cold start (no pedal, just turning the key) I get a nice fire up, 1500 rpm for about 3 seconds, then coughing, sputting, and the engine dies. The second attempt is usually less successful. If I give it ANY pedal during the (brief) nice idle, it seems to sputter and die quicker. If I start with a bit of pedal pressure, it doesn't even get to that nice, brief idle point. On the other hand, warm starts are easy.

It sure feels like flooding to me. Since my head is immersed in my B18 rebuild, at the moment, I'd really appreciate the lowdown on this CIS cold start problem. My head can handle only so many engine details at a time!

thanks,
Tom in Charlottesville
'76 245dl
'73 1800es
'67 122 wagon
'65 122 s

I think your running too lean rather than flooding the engine on you cold starts. The nice 3-second idle you are getting is due to the cold start injector injecting extra fuel while the starter is turning. But once that EXTRA fuel is used up it is back to a poor idle. I would first check for vacuul leaks anywhere and everywhere. Next remove and clean your Control Pressure Regulator (CPR) located below the intake manifold (rectangle type box with two fuel lines). This devices helps richen the mixture on a cold engine in order to allow the engine to run smooth and warm up ASAP. After I cleaned my CPR my car always started up on the first try and kept the high idle until the engine warmed up. Run a search for CPR or Control Pressure Regulator. Good Luck!

Sincerely,
--
Julio Meza

1979 264GL B27F 125K --> BW55->M46, CLS, IPD Sway, 81+ Dash, Gauges, Flat Hood & E-Codes

1979 262C B27F 160K --> Restore Project w/Possible B280F

1984 245DL 214K -->Wifemobile

Thanks Julio, that was the detail that I was lacking. I'll give it a try--gotta do something, since the condition is definitely getting worse.

tom

"It sure feels like flooding to me"

Why guess? Pull a couple of plugs next time you try it. With a car that old, there are too many possibilities to start guessing. But Mario's idea to check for some known suspects can't hurt.

I use Propane to test for vacuum leaks (less messy than carb cleaner or other sprays). Take the nozzle tip off a propane torch and replace it with some snug fitting rubber hose about 2 feet long. Practice with the valve to get a moderate gas flow (not a roaring blast).

With the engine at a warm idle (or barely running if that's all it will do), open the gas valve and poke the end of the hose around each injector for a couple of seconds. If the seals leak, you should hear an RPM change when the propane gets sucked in and burned.

Do the same around any other suspected areas, like hidden vacuum hose ends and the intake manifold gasket itself.

To block the breeze from the fan, lay a piece of cardboard from the fan shroud to the engine.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Would a can of Aerostart be suitable for this test? I'm trying to track down a leak myself.
--
Drive it like you hate it

"Would a can of Aerostart be suitable for this test?"

I'd say No, if it's an ether-based starting fluid. If it's just a combustible volitile like carb cleaner, maybe.

I just don't like sparing and fogging that stuff around a running engine. IMO, the propane method is safer because the combustible volume is smaller and can be directed more accurately. Sort of a revolver vs. shotgun analogy as I see it.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Hello,

Check for vacuum leaks and bad injector seals. My 82 had cold start issues until I changed my seals.

Mario