My rebuild thread (2 Viewers)

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alrighty, did a little more work today. I dropped the Injectors off to be tested, so we'll hear results of that hopefully soon. Popped the cam' into each cylinder, and there's no bits down in them and theres only light carbon marks of valves on a few of the cylinder number 3 and 4 respectively, which seems to be "normal" in terms of my research on the 1hdt. sorry for the dirty screen in the one photo.

I then drained my oil and saw no bearing flakes, thank god! I tried to get the cam up there to look but it's a crappy one so I couldn't see much. I'm still preparing to do BEB's just for s***s because why not.

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Also, I'm prepping for the ACSD removal and have a few questions I can't seem to quite find the anwser to. I remove the vac valve off the top which has the cold idle adjustment, and do i remove the solenoid over by the battery as well and plug the vac port down on the vacuum pump?

I think some of my confusion is all the photo's I see are possibly cruise control model rigs and have a bunch of other / different things down there.

I see conflicting information on plugging the two coolant lines versus hooking them together. does it actually matter?

I want to make a fresh writeup on this when I do it since a lot of the old ones are missing photos. Just want it to be correct to help out future issues with other people.

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Hey @mattimooseprime , I saw that you're going to be removing your ACSD from your injection pump. If it helps, see the following link from a post I made when I removed my ACSD from our 1991 1-HDT injection pump. It's at: ACSD Removal 1HD-T

I just connected the two coolant ports together with about 15-16 inches of coolant hose and some smaller hose clamps to hold the ends on. The crux to this whole ACSD removal is how tight/stuck your hex key bolts are that hold the ACSD onto the injection pump. If they are not crazy tight then removal is pretty straightforward. If they are stuck you end up having to be 'creative' I guess.

Hope this helps you out! We don't have cruise control on our 91 HDJ81, but it a manual (5-speed) as well, so perhaps there may be some differences.
 
If no4 still doesn't hold compression, squirt a couple of teaspoons of engine oil into the cylinder, and try again. If it hold compression with oil in it, it suggests bad rings, if it does not it suggests a cracked piston, or f***ed rings

The theory is good (the oil gets around the rings and helps seal) but if the pistons have deep domes in the middle (eg direct injection) the oil never makes it to the rings.
 
I doubt it's actually a compression issue, pretty sure it was due to not being able to get the quick connect on it effectively. I'll be able to do it again soon, when my new tester arrives in the mail.


On an unrelated note to compression and back to the acsd - the Allen /hex head bolt struggles most people have kinda make me lol a bit. Not in a mean way, just a "lol I know thenstruggles". I work with stainless hex daily so I was pretty prepared. They came out smooth :)
 
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results from my injectors came in, they're pretty much shot. Going to the shop tomorrow to discuss rebuilding them, or buying new. also hopefully picking up a acsd blockoff plate as well.

Other than that, I haven't really progressed much. weather's been s*** and work's been busy.
 
Well......Bad news. Lol.

The injectors were NOT the main cause of the issue, but I can definetly tell they were needing repair. it Idles better! I also got everything primed right up from the ACSD removal, and it only took combined about 5 seconds of cranking over between 3 separate start attempts to pull fuel.

This video should sum it up - Watch the belt. needless to say I was surprised. I'm thinking fuel pump. What are your thoughts? I instinctively pulled the belt off immediately after that video but forgot to set TDC (whoops - no big deal, I can do that later) and the fuel pump seems to have a "clunky" amount of movement too it. Hard to explain it other than that, it's like a tooth's worth of slop, but it's hard to make it move.

 
The injection pump is gear driven off the crank. The timing belt drives the cam off the injection pump so if your trying to turn the injection pump, you're trying to turn the whole engine. I personally don't think its the root cause.
 
That's what I thought. I expected a little bit of backlash, but not a clunky "popping" feel. I'll try and snag a video of what it's doing.

I've never seen a tensioner jump like that, has anyone else? I laughed when I saw it the first time. they're just spring tension and not oil pressure driven, why would it move?

I'd expect if my belt skipped a tooth that I would have already destroyed all my valves, yes?

I'm trying to avoid pulling the pan - if I have to get that deep into it, I'll take it to a shop. I have a gravel driveway and currently don't have the means to get this done as cleanly and efficiently as I'd like. the way it smokes when it runs just points towards fuel, so I am having a hard time getting past that.


The two dowel pins are NOT required for the tensioner to function correctly, are they? I found one of them on the ground the other day BEFORE pulling my belt. I was just doing some reading and saw a picture of one, and that answered a question I had about what it was. I found it on the ground after pulling the ACSD because I dropped a spring so I assumed it was from that, but apparently not! It must have fallen out when I pulled the timing belt cover off.
 
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Back to work! I replaced my idler pulley, which was bent! Waiting on a new timing belt to come in. Pictures soon to follow. I'll be curious to see if my timing belt stretched and if I skipped a tooth. I did notice a small ding in my IP gear, and a similarly matching ding in the idler dowel pin. Tossing around the idea that it fell out, went into my belt, and caused it to jump a tooth and bend the idler. Unlikely, but fun to think about nonetheless.

Once the belt comes in and is on, I'll be timing the fuel pump. TDC has been set and I am waiting to wrap this up.
 
The two dowel pins are NOT required for the tensioner to function correctly, are they? I found one of them on the ground the other day BEFORE pulling my belt. I was just doing some reading and saw a picture of one, and that answered a question I had about what it was. I found it on the ground after pulling the ACSD because I dropped a spring so I assumed it was from that, but apparently not! It must have fallen out when I pulled the timing belt cover off.

That is interesting, as are the marks you found that seem to match on the pin and pulley.

If the pins are needed or not would be in individual call. It can be interpolated as pictures of the replacement oil seal cover from Toyota (if you needed a new one for whatever reason) shows no holes for pins. A fellow from the Philippines posted up photos of his engine which has no pins on this thread.

Any further progress?

hth's
gb
 
Good news! With the new timing belt, everything is back together and it is RUNNING LIKE A CHAMP.

I'm guessing the root cause was a weak tension spring and the obvious bend in that pulley. with my injectors rebuilt it's got gobs more power, which is fantastic. I did remove my aneroid pin to inspect it, and I'm 90% sure it went back in exactly the same direction, but i'm going to bring the truck to a shop and have them give that a once over and check timing on the pump while they're there. I've been driving it nonstop the past few days to "stress test" everything and other than a few starts where it chugged for a couple seconds, it's been flawless.


I'm so happy that it's back and it wasn't something more severe. I spoiled myself and bought a new stereo for it to celebrate lol. I will post updates on fuel pump timing when it gets done, too.
 

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