So I have been noticing on cold morning that my engine idle pretty rough for a while and it sounds like there is either a bad piston ring or sticky injector. I did a crank test and did not notice any fast spots, so I hope I can rule out a bad piston ring. Does anyone have any advice on how to determine if it's a sticky injector or something else? Also, there is at least 1 non functioning glow plug, and probably more. Thanks in advance for the help!

 

You are probably talking about the "cold start" romps, that are relatively normal with these trucks. Running 100% functioning glow plugs/relay, in addition to a 5w40 synthetic oil helps reduce/eliminate it.

 

I thought that too, but i can hear a "puf puff" coming out of the exhaust, which i thought might be a sticky injector or a bad piston ring. also my truck blows a bit of blueish smoke for about 10 minutes after startup. when i started it yesterday after driving about 130 miles the day before, it was very rough and it almost sounded like a dead miss when i started driving. it did go away after about 5 more minutes.

 

Could be worn poppets in the injectors 5w40 may help that. Glow plugs should cut down on the smoke too.

 

so judging by the placement of the poppet valve, that looks like it'll need a replacement or rebuild on the injector. is there any way that you know of to find the malfunctioning injector?

 

Does the miss always go away when warmed up? You can unplug one of the four harnesses at the vc's at a time and start it. If its missing at the time, the one that makes the least difference will narrow it down to one of two injectors. Then you can pull the vc's and start it and unplug one at a time of those two and find it.


What kind of shape and what brand are your valve cover wiring harnesses?

 

http://www.google.com/url?sa=t&rct=j...83829542,d.aWw

 

The only other choice is to shim the injector, to get it back into spec. That is determined by removing the solenoid and trying to fit a 2 thou feeler under the armature plate on each corner. Clearance is supposed to be around 2-4 thous, and the valve gets warn. Once it gets around 2 thos or less then shims can be tried, but real fix is injector rebuild.

You can also remove valve covers to see if injectors are all releasing oil the same. A weak one should show up.

If I were you I would change the glowplugs and the relay (upgrade to a Stancor/ Western Plow)these are critical to good starting on these trucks, consider changing over to 5w40 Shell Rotella (if on an oil change interval). This makes sure that the known problems, to include old/sheared out oil are taken care of.

While you are in there you can checkout the oil spill, and using the results of that make a determination into if you feel like shimming is necessary/will work or rebuild is necessary.

I had this same concern and it went away when I switched over to 5w40 Rotella Syn. This is if you are referencing startup romps when cold.
Good luck.

 

thanks for the advice and the other thread! i'll definitely pull off the valve covers and check the oil flow. switching to 5w-40 sounds like a good idea. im about ready for an oil change too. the glow plugs are going to take a little while because of the cost but i know they need to be pulled soon.

 

You can also ohm them out at that valvecovers and replace them individually when you find a bad one. I don't do it that way, but if money is tight... Really though glow plugs are about the same price, maybe less, than an oil change to 5w40 Shell Rotella...

 

i have tested my passenger side glow plugs, and one is completely gone and the others are probably half gone. I may go to ford and get 4 or so. i dont know when i'll be able to replace them because of snow in the forecast and temperature.

 

so just an update, I changed my oil yesterday and I also changed my HPOP oil. after I started it, I could hear the difference immediately and it started much easier than usual. I sounded a lot quieter than it pretty much ever has, and there was no injector noise. I also added a quart of Lucas Oil oil stabilizer. hopefully this will put my injector problems at bay for the time being.