Hi Martin!
It looks like we're both late LATE
LATE night types!!!
Looking at everyone's post dates I may be too late with this. It seems that the other posting members are all talking about knocking sounds, but I don't see any mention of this in YOUR post. please de-confuse me...
If you still have problems, read on, and if you don't please let me know here by posting another note. Want to sped things up? Reply here with a date and time to be here, and we'll set up a private chat to exchange phone #S +/OR Email addresses. I can TALK WAY faster than TYPE!
First off-
It sounds like you ACTUALLY have a glow-plug controller problem. The hard starting and big clouds of white fuel-scented smoke would both be symptoms. I'm reasonably knowledgeable on this subject, and electrical problems of ANY kind are one of my favorite things to hunt..... for further info we should just use a PHONE call.
What year is your truck? pre-to-early '87 uses the "FAST-START" glow plug control system, mid-to later '87 and newer uses the "SOLID-STATE" glow plug controller. The glow plugs are quite different as well, so make sure which system you have. I'm going to TRY to send you diagrams of both systems straight out of the Navistar engine manual. ( I paid $185 for this book, but it was ABSOLUTELY CRUCIAL to have because from early '87 to late '88 BOTH Ford and International made TONS of engine design changes and ONLY THIS PARTICULAR MANUAL covers all of them. It turned out to be THE BEST AUTO TECH MANUAL I've EVER PURCHASED, and I have bought MANY!)
Any way, in order to be as helpful as possible, please fill me in with the full story ( START with your truck's year and engine info. ( not mentioned in your post ) If please get the Vehicle Identification Number ( VIN ) on the printed tag inside the driver's side door jamb. For now
I'll call the engine serial # optional for OUR conversation, but it's so good for an owner to know for so many reasons you should get it and write it down somewhere for yourself.
You SHOULD find hiding right on top of the engine BLOCK ( NOT on the heads or manifolds etc... ). It's a hand-STAMPED #- NOT CAST.
You'll probably have to scrape off the grease to even find it, so to save you some sweat, here's a VERY precise description of where to scrape: CLOSE (1/2-3/4") BEHIND the timing
gear cover casting ( the injector pump is mounted on this ) on the DRIVER'S SIDE right between the injector pump itself and the cylinder head ( still on the driver's side ). there should be a sheet metal valley cover down there, so look or scrape ( or both ) right beside it right down to the engine block casting itself. The # itself SHOULD look something like this : 7.3 DA2 U 123456
good luck finding it. I took a few phone-based pics of mine, AND wrote it into my engine manual for future reference.
Sorry about getting so long-winded!
OOF!- I'm sounding kinda side-tracked, so back to the real meat of this post :
send me ALL the DETAILS, recalling WHAT YOU did WHEN and What happened as ( or just after ) you did it. and since I wasn't there, include sounds and smells as well, and WHEN in this process they appeared, they can be really good clues when combined with the rest of the info. Also add just how mechanically inclined you are, maybe we can chat on a higher level.... save us both some time.
Hope you give a call.
-Bob