Starting issues
 

Hello, everyone.

I've searched the forum and found similar issues, but none exactly like this so...

I have a 77 240D W123 Automatic. When the car is cold in the morning (I mean on a warm spring morning), the car won't crank unless I shoot a touch of starter fluid into the air intake (I know, I know, shouldn't use starter fluid).

Now, when the car has been running for a few minutes, it will crank up just fine. I did some running around yesterday and, after finally getting it started, I made several stops and the car started normally each time. Went back out several hours later? No start. But, again, starting fluid worked.

I did change the primary and secondary fuel filters just before this happened. Could it be air in the fuel lines? I feel like I pumped it up plenty before starting it. If it is air in the lines, how do purge it?

Thank you!
elcaBob

I am guessing the 240d is diesel... You didn't mention the glow plugs. Is the glow plug system working correctly?

Seems to be. Everything was fine until I changed those fuel filters.

Hi Bob,

I am not a diesel expert. There are a few diesel experts that follow the Vintage forum. There are way more diesel experts on the Diesel Discussion section of this forum. You may want to post your issue there if you don't get a quick response here.

Diesel Discussion - PeachParts Mercedes ShopForum

I moved the thread to DD for you. I'd agree that it sounds like Glow Plugs, and you'd probably want to test your GP circuit, but I will defer to people with actual Diesel experience :)

Probably has the "loop" GPs so one stuffed one stuffs them all. Highly recommend changing to pencil plugs. You'll never have that trouble again.

If it starts on ether it won't be a fuel problem :)

Also, crank means the engine will rotate, not start ;)

Thanks for moving this to the correct forum!

I just wonder why the glow plugs would pick just that exact time to start being problematic.

did you express all the air out of the system when you changed the filters, back in my diesel days I struggled a bit with my 300D after a flter change, they can be a bear to get rid of ALL the air, she would not start until I did.

I opened each connection , cranked until I had good flow, and moved up the line, it was messy. Did you fill the canister fuel filter prior to replacing ? Are you sure you are not sucking in air? Look also at your manual fuel pump connection , is it sucking air in?

if you do have the old style loop plugs, then testing them is easy; open the hood and start glowing. do the loops get red hot? i'm guessing not.

I don't know the old loop plugs. The pencil plugs are easy to test. Periodically, I remove the GP connector and measure resistance to ground of each of the 5 pins (<10 ohm means not broken). With plug connected, I verify 12 V (from gnd) at each plug while the GP relay is actuated (20 sec after key turned to "run"). You can get a free multimeter at HFT w/ a coupon.