Crank, no start except with starter fluid

[malpana]

Hi, all. Apologies if this has been covered but my thread search didn't catch it. The 6.5 in my sig has had intermittent trouble starting lately. Today I cranked it several times with no luck. In the 80's outside, good battery voltage, cranking fast enough, could hear the lift pump running while waiting to start, good flow with the fuel T valve open (both with the terminals in the relay block jumpered and with the relay installed), had been driven about 1.5 hours earlier, plenty of fuel in the tank. Right after I gave it a couple of squirts of starter fluid, it fired right up and ran just fine all the way home - no stalling, no stuttering/hesitating, normal smooth acceleration. Turned it off and then fired right up a couple of minutes later. Before I start tearing into it, any clear avenues to pursue? Many thanks in advance.

[DmaxMaverick]

Welcome aboard!

First off, don't use "starter fluid", ever, outside an actual emergency (about to be run down by zombies or the wife/significant other is going into labor). It likely killed whatever was left of your glow plugs, among other bad possibilities. When your truck was new, it had a sticker under the hood that warned bad things would happen if you did. The original issue was likely related to the glow plug controller/relay, or possibly a fuse. Many 6.5's don't like to start warm without the plugs working well. Hot, like shortly after a shutdown, it hot, and will usually start just fine. Cool off for a bit, and no go. Dump the ether and work the problem. Check that all the plugs have continuity to ground, and they are all getting 12V when you turn the key, before, during and after the starter does it's thing. Pull the plugs you can reach and test them. Put 12V to them for a few seconds. They should "glow", hence the name. They'll also burn the hair off the devil's butt, so be careful about that.

[arveetek]

Ditto what Maverick stated above. Sounds like a glow plug issue to me.

Casey

[Robyn]

Just an added perk.

The RH side plugs are not hard to get to... Jack up the RH front place safety blocking/jack stand
Remove RH tire/wheel.

Carefully remove the retainer buttons on the rubber inner fender flap.

First 3 glow plugs are staring at you.....#8 is a pain and must be accessed from under the rig.

Leaving one dead one is no biggy things will be fine.

Use 60G plugs ....These are far better than any of the earlier ones.....

Sit on a box and go at replacing the plugs
Could be a bad glow controller.

Have a helper operate the ignition key while you check voltage at the plugs.
With wait to start light on you should see battery voltage at the plugs.

Another possibility....The late model 6.5 had a glow inhibit built into the glow controller.

Before we tear into things....Use a jumper that can jump the large terminals on the glow plug relay (Manually apply 12 volts to the plugs) Apply voltage to the plugs and have your helper hit the starter 15 seconds on the plugs should be enough......
The glow plug controller should click when the key is turned on...If it is silent...Not good.....
Check it out

Good luck

[malpana]

Thanks for the help, and sorry for the delay - I got swamped with other stuff. I should've checked for codes before I disconnected the batteries to check if they could hold a charge and pass a load test individually. I'm going after the glow plugs as soon as I have a chance.

[Robyn]

Keep us in the loop

I fully understand about "The other stuff"