I just switched out the glow plugs on my pig and I was wondering if you can read them kinda like spark plugs.

2 were wet looking and the others were ashy looking. They were autolites so Im glad I got them out of there. I figure ashy is the norm but does the wet ones mean leaky injector?


My other question is,,I am going to switch out the return lines tomorrow and was wondering should I pull the injectors and take a peek? the truck only has 97k miles on it.

If I do pull the injector should i replace the copperwasher? what about the olives at the pump. The olives are not leaking so I didnt know. thanks

 

i am not sure about reading the plugs. yes, if you remove the injectors then you should get new copper washers. if nothing is leaking though i would not bother with the return lines or olives at the pump.

 

The back left 2 are leaking and pooling up so thats why I am doing the lines. I left that part out lol

 

it's pretty much time for a new set of injectors anyway.
mine were pretty bad due to age and plowing hours on the truck at just 50k miles when i got it.didn't really know how bad they were until i put a set of remans in (from U-Haul inventory sale.i kinda think they were new old stock not reman but no way to know i guess.)
smoothed right out and got bump of the key quick starts instead of a few seconds cranking.
ideally they should be replaced every 100k miles.or imho every 10 yrs whichever comes first.sooner if it's a plow truck/lots of off road and or idle hours.

 

I'd replace them as well. I'm just doing mine for the first time, 26 years. I only have 130K on the truck, but I'm doing everything. Its ran bad for a while now so its time. It sat alot. Injectors are cheap for these trucks. Not like the powerstrokes.

Chet

 

In my experience, you see wet injectors but not so much GPs due to one of three reasons. Keep in mind that injectors do not seal via the threads in the upper head.

The first and somewhat common scenario is the introduction of fuel/oil/solvents into the cavity before removing the GP or injector. If you have a pool of fuel from a leaky return line and you go ahead and remove the injector, you can expect that fuel to drip down the injector as you loosen and remove it; this usually occurs when spilling fuel while removing a return cap.

The second and most common scenario is similar to the first but happens over a longer period of time. Leaky return lines will pool fuel above the injector and eventually seep down through the top threads of the injector and be caught in the head between the top threads and the crush washer. Water will also get caught here and will cause the injector to rust. Water does not need to be present to know it was there. Water will eventually boil off, leaving only rust as an indicator (very common in trucks that have sat for a long time or are not driven regularly). The Diesel fuel that gets in the injector cavity will also evaporate smaller carbon chains thus losing its smell of Diesel but retaining a light oily viscosity.

Lastly and least common, due to the torque between the injector threads and the nozzle, is internal leaking from an injector. If you have an injector that seems to leak and pushes fuel up from the top threads, this may be the issue. I would attribute this scenario to poorly manufactured injector, improper torquing, or severe neglect.

Glow plugs however, are not like injectors, if they are wet, you are looking at it from inside the cylinder or contamination during removal.

 

Thanks for the input. I did the return lines today and noticed the injectors were stamped remanufactured 1996 on them.
After I did the return lines I am still getting fuel leakage on the same 2 injectors.

I know the cups are seated well so does this mean what? The fuel looks like its coming from the flair where the fuel line screws on but the flair and threads look good.

Sorry for all the questions. On my atv/sxs and rock crawlin sites I can answer most questions but I am a newbi on this old iron.