New plugs, still white smoke & no start

[HardCorps79]

So, after a long, cold hard winter and burning up my plugs, I got some new ones. Ordered direct from indusadist. Pulled the old plugs which were all pretty blackened and rusted, but none were swollen. Installed the new ones without incident. (All Wellman 070s)

But nothing changed. I'm still only getting white smoke. Engine cranks and cranks but won't catch and fire up, even with temps in the high 70s.

Some of the connectors seem a bit loose, so I'm going to replace all of those, but I wonder if there isn't something else going on. If it were a GP issue, shouldn't it still fire up with temps close to 80 outside?

Also, the wait light comes on and stays on for way too long. Relay clicks on, stays on for a long time, then finally clicks off, but over a minute later. Never really stayed on for more than 10-15 seconds before this past winter. Also, when it does fire up periodically, sometimes the wait light comes on for a few seconds while running right after start-up.

All plugs still show proper resistance (most are right at 1.5). Relay shows 13v at top post and 25v at bottom when activated.

From my searches on here, I'm thinking possible solutions are:
-new GP connectors
-GP relay
-bypass GP control card (haven't checked if it's burnt up yet, we'll see)
-Replace lift pump (AC Delco 43254?) & Install new check valve (HPCA off IP?)

Any other thoughts? I don't quite get the "bypassing the resistors on the firewall" mod. Not sure if that would apply to my situation.

Sometimes after trying to cycle through 4 or 5 times and shutting it off to let the starter cool down, it will finally catch and then it runs like a dream (other than a serious vibration at speeds over 55mph, but that's another issue for another post...). Once it's warm and pumping fuel, it will be fine to drive around town. But if it sets for more than 4 or 5 hours, it goes back to hard starting.

Seems like the problem I'm having isn't unique, but the causes are wide and varied. Any suggestions?

 

[cjtroutt]

After it off for an while sounds like the return lines in the inj if they suck air it will be hard to start.
Here is the photo of return line & inj.

 

[Ken_86gt]

Most of these trucks still need glow plugs to work to start easily even in warm weather. It sounds to me like you are still having a glow plug issue based on your comment about the time that the light stays on. As a test, try using a jumper wire directly from your 12V battery + to the wire that goes to the glow plugs -after the relay, for 6 or 7 seconds and then immediately start it. It should fire right up. If not that only leaves the plugs themselves (or bad connections at the plugs) or the fuel system.

 

[Shop Rat Fab]

With the white smoke it appears you are getting fuel into at least some of the cylinders or maybe all of them. See if you are getting 12 volts to all the glow plugs if you are and you know your fuel is good there could be a concern with your base engine compression being low I.E. worn out engine.

 

[jimmy-90]

Dang man!!! If your glow plugs are staying on for like a whole minute or so I would definately just say ta-heck with it and wire them manually at that point. I would have guessed that if they stayed on for that long the tips would have over heated and broke off. If you do the manual gp. conversion and make sure that your plugs are still good and still have a real hard time starting it I would look for air in the fuel lines.