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7.3L IDI Diesels (Not Power Strokes) Technical discussion of topics related to vehicles powered by the 7.3 Liter In-Direct Injection Navistar engines.

Thread: what is this gizmo? Reply to Thread
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  Topic Review (Newest First)
02-11-2019 04:41 PM
RT Check your private messages. I found you a new one!
02-11-2019 09:55 AM
Steve83 So, which JY were you talking about being 120mi? Lost Mt.? Marietta? Hunter? Have you checked Call's on Main St. (Woodstock)? It's not nearly as big, but it looks decent-sized, assuming they have some recent wrecks under all those trees.
02-11-2019 07:03 AM
dirtyBob Good idea. The truck is advertised locally for sale also, if anyone wants to message me about it.
02-10-2019 10:59 PM
Steve83
Quote:
Originally Posted by dirtyBob View Post
...to the junk yard (120 miles round trip)...
Put your location in your profile - someone might be close enough to help you.
02-10-2019 03:59 PM
LMJD You're welcome.
Quote:
Probably mine has air in the lines despite trying every trick known to man to cure that, return lines, olives, washers, on and on,
Yeah, like I stated above, mine starts real quick, but it also lets me know real quick-like when I suddenly develop a air problem in the drainback system. I can't remember and I could be wrong but I think the cold timing advance is governed strictly by one of the 2 coolant temp senders like the fast cold idle is.
And if your starter is due for an overhaul, getting it rebuilt will make a big difference in cranking speed and quicker startup.
02-10-2019 10:26 AM
Mark Kovalsky
Quote:
Originally Posted by pnose View Post
I believe it to be a barometric pressure switch...it's purpose is to adjust air mixture relevant to the elevation your at.
On a diesel? How would that work?

On a diesel the airflow into the engine isn't controlled, it's wide open all the time. Power is controlled by how much diesel is injected. The injection pump is all mechanical and is controlled by the cable from the accelerator pedal.
02-10-2019 10:11 AM
dirtyBob
Quote:
Originally Posted by LMJD View Post
Not true, back in the day FoMoCo stated the cold advance and cold fast idle are strictly to lessen cold engine smoke complaints. Bought my pickup new in '91 and disconnected the timing advance about 2 weeks later. With the advance on, it sounded like the pistons were going to fly through the hood. Can't be good on an ice-cold engine. And with starting, glow plugs and fuel system in A-1 shape mine will start in 3 seconds at 10-20. According to the shop manual, the component you have circled is the low vacuum warning switch.
Ding ding ding. That's it. Part identified (thank you). Apparently it is wired to the idiot light for brakes so you know the vacuum is low if it is. I just don't understand why the cold timing advance is not working now, but maybe it's because when I threw out this smoking low vacuum warning device, out I also left the vacuum tube disconnected and the cold advance is run by that. It's nice to know it won't make the engine easier to start (thanks). Probably mine has air in the lines despite trying every trick known to man to cure that, return lines, olives, washers, on and on, also probably a somewhat worn starter and weak-ish batteries now. I might try and replace the (now identified) low vacuum warning switch since power brakes are handy on these trucks. I bet I'm headed to the junk yard (120 miles round trip) for one.
02-10-2019 09:56 AM
LMJD
Quote:
Originally Posted by pnose View Post
I believe it to be a barometric pressure switch...it's purpose is to adjust air mixture relevant to the elevation your at.
I'd be interested in knowing just how that works??
02-10-2019 09:10 AM
pnose I believe it to be a barometric pressure switch...it's purpose is to adjust air mixture relevant to the elevation your at.
02-10-2019 09:04 AM
LMJD
Quote:
It needs the cold timing advance to start. You can start the engine but without the timing advanced its hard on batteries. This thing apparently controlled it.
Not true, back in the day FoMoCo stated the cold advance and cold fast idle are strictly to lessen cold engine smoke complaints. Bought my pickup new in '91 and disconnected the timing advance about 2 weeks later. With the advance on, it sounded like the pistons were going to fly through the hood. Can't be good on an ice-cold engine. And with starting, glow plugs and fuel system in A-1 shape mine will start in 3 seconds at 10-20. According to the shop manual, the component you have circled is the low vacuum warning switch.
02-10-2019 08:31 AM
dirtyBob Here's a picture of the missing gizmo. This is from a 1985 with the 6.9.

Attachment 126614

This close up pic was taken from a 1996 7.3 powerstroke engine bay. Apparently this mysterious highly confusing strange bizarre wonderful missing mystery gizmo was used to control timing advance from about 1982 to the late 90s. Nobody owns one?
02-10-2019 08:17 AM
dirtyBob It's not a canister. I broke the old one open and it had this spring in it, thermal type of spring. There was a diaphragm too if I recall. Here's the hose. A vacuum hose routing diagram would really help. Without this mystery gizmo from the 80s of the ford diesel pickup truck world, starting the truck is very hard. It needs the cold timing advance to start. You can start the engine but without the timing advanced its hard on batteries. This thing apparently controlled it. Does anybody know what this thing is called and what one can do to replace it when it burns up, as did mine? It's like out of production by 20 years at this point I am guessing. And yeah, I know I need a newer truck.
02-09-2019 05:52 PM
RT
what is this gizmo?

Take a picture where the hose goes. Looks small to be a vacuum canister.


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02-09-2019 11:56 AM
dirtyBob Bump. Doesn't anyone know what it is?
02-06-2019 11:51 AM
Steve83 The first few posts in this thread explain how to post pics anywhere regardless of post count:
How do I post pictures, sounds, and or videos? | SuperMotors.net Forums | SuperMotors.net
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