My 1990 F-250 needs new glow plugs, are they easy to replace if youve never done it before?

Also I have diesel leaking out as well, its leaking on the passengers side of the engine and it drips just in front of the oil pan, I just had new fuel lines put in two weeks ago, its leaking about the size of a 1 gallon milk jug bottom in 12 hours, someone told me it might be my lift pump going out, would this be correct?

 

They can be but sometimes the ceramic tips swell up and can break off inside the cylinder just be careful.

 

Glowplugs - deep 3/8" socket is what you need, 1/4"-drive is best cause two of the plugs are kinda under the injector lines and you gotta fish the socket between said lines (loosen all the line clamps before you attempt this). Usually a pretty easy and straight-forward job, unless you get a plug that's so stuck it feels like it's holding on to the head for dear life - if you encounter one or more of those do not force them, instead soak them with PB blaster and allow it to do its thing, then slowly turn the plug back-forth a little bit to help the PB blaster go through the carbon buildup. Do you know what plugs you have in there now? Motorcraft/Beru is what's best, so that's the only plug you should install - Autolite is NOT Motorcraft, they are a different brand and they are junk cause they like to swell up and die and then promptly break tips off when you attempt an extraction operation. Bosch is pretty much the same junk as Autolite, my truck came with a set of Wellmann plugs tho and they seemed to work pretty good and last decently long and then came out very easy...

On the fuel leak - your lift pump is in the front passenger-side corner of the engine, yes, however there is also a rubber hose that runs between said lift pump and the steel fuel line on top of the frame rail - that hose gets hard with age and mileage and cracks, sometimes it also develops leaks. Do you have a hard start condition also?

 

Never sieze is your friend for glow plugs.

I never had any issues changing glow plugs on a 1992 F250. But I always applied never seize to the threads.

The glow plugs are easy to check...just hook the ground end of a test light to the positive bat cable, and touch the glow plug terminals...if the plug is good..the light will light.

I always had more issues with the glowplug relay that set on the glowplug controller box at the back of the engine(mine was a 1992 7.3). I replaced the relay several times...and if I recall...the parts stores and dealerships at the time would try to sell you a complete controller/relay assembly for a couple hundred bucks...when all that was bad would be the relay itself(like an $11 part).

 

The thing with the glowplugs relay, is that while it looks very much like a fender-mounted starter relay it's actually much heavier-duty on the inside, contacts are much more massive - at least they are in the relays these trucks left the factory with, the newer aftermarket and even OEM parts could very well be inferior in internal design...

As for the plugs, you really wanna test their resistance, you need an ohm meter for that - one lead the meter on the stud of the plug, the other on the threads, IIRC under 4 ohms each is what you want...

 

LOOK FOR THREADS ON COLD STARTING PROBLEMS, ALOT OF INFORMATION. WHEN I TESTED THE GLOW PLUGS WITH AN OHM METER THEY TESTED AT .8 OHMS WHEN THEY ARE REMOVED FROM THE HEAD, THATS GOOD AND THROUGH THE WIRING HARNESS I GOT 20 OHMS BETWEEN PIN 1 AND ENGINE GROUND (FIVE PIN CONNECTOR ON VALVE COVER, THERE ARE TWO CONNECTORS PER VALVE COVER) SAME GOES FOR PIN 5 AND ENGINE GROUND; YOU HAVE TO HAVE THE KEY TO THE ON POSISTION TO TEST BETWEEN PINS 1 AND 5 TO PIN 3 WHICH IS THE COMMON GROUND, THIS IS THE HALF THAT PLUGS INTO THE VALVE COVER HALF OF THE CONNECTOR, DO THIS TEST WITH THE VOLTMETER SET FOR DC AND WILL TELL YOU IF THE COMPUTER IS SENDING THE GROUND AND THAT PINS 1 AND 5 ARE HOT, I GOT JUST OVER 10 VOLTS AT PINS 1 AND 3 AND 5 AND 3, NOT SURE WHAT THE ACTUAL VOLTAGE DROP MAXIMUM IS.