Slow start at 47 °F ... Glow plugs?

[rhkcommander]

2 seconds to restart is fine when cold.

Yes verify the glow plugs are good. The wiring to them can be bad too, as well as corroded connections, bad fuse links, etc.

If it took several seconds the first try and 2 on an immediate restart, i would assume air intrusion. If you make a toggle switch with a large and a small ring terminal you can attach it to the starter relay big batter post and sense little post to crank while under the hood. You can then see if air comes out of the fuel filter Schrader or fuel right away. My old engine acted this way, always would have air hissing when cranking with key on until fuel built up. Wouldn't start till purged, then would start great till sitting 24+ hours

 

[rhkcommander]

Just watched your videos, pretty sure it's fuel intrusion like my old engine. Second video in you can hear it try to light for a split second then keep cranking on. That and the fact that a cold restart is so much faster than the first start. You haven't built enough heat to be worth a damn, but you would have built up fuel in that amount of time.

Yes these engines run on compression, but at 40F I haven't seen one of these start without some heat assistance or ether.

I was suggesting bypassing the glow plugs because the automated system can be temperamental. Just 1 bad plug will have it spazz out and be ineffectual. Your engine can start with 7, maybe even as few as 5 plugs depending on engine heath and other things. But not with the automated controller! A quick test for this is to manually cycle them and try to start. No change? Not the plugs. Starts in a couple seconds, probably some bad plug(s) and the controller $#!+ the bed. If you don't know what kind of glowplugs are in there, wouldn't be a bad time to take them out and see. If you are sticking to the automatic glowplug controller I would only use motorcraft beru zd-9 if they have the bullet plugs, and zd-11 if they are the spades I believe. If you go manual, I found that the motorcraft beru take at least 7-10 seconds to build enough heat for reliable ignition, whereas Bosch plugs were like 5 seconds. Some people like wellman, but I only ever trusted Bosch or Beru. If they are champion or autolite plugs toss them immediately! Those guys like to burn the tips off, swell, make your life hell.


If you unhooked the automated controller you could easily test if it's air intrusion without removing anything else: unplug the controller, floor the pedal, crank it for a good 10 seconds, then glow it and try to start. Does it still take 10+ seconds or 2?


Leaky oil has nothing to do with starting or running, unless we are talking about a runaway situation



As for the source of air intrusion, hell anything from the tanks to the engine. Most of the time it's either the return line system, loose or cracked fuel lines between the IP and injectors, loose fuel filter, leaks by the manual lift pump, etc. I think there may be a one way valve to prevent leak backs too, if so that was probably my problem since everything else was dry as a bone...

 

[nelstomlinson]

So, maybe my plugs are just old and need replaced? Why jump right to mechanically toggling the plugs? Is there a benefit here vs. just replacing plugs?

Lift the wire off the top of each glowplug, and read the resistance from the top terminal of the gp to the battery negative terminal. It should be well under 1 Ohm, probably about 0.5 to 0.1, should be about the same for all of them.

If you get no reading or a definite zero reading, that's a bad plug, replace it. This is so easy you should do this first, always, anytime there might be a glowplug problem.

 

[Farmer Rock]

The easiest way to determine between GPs and air intrusion is use the block heater or pull the filter.We are running in circles here




Rock