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Discussion Starter · #1 ·
My 95 T100 has been sitting up due to a previously discussed transmission issue. I finally brought it home from the mechanic's shop yard (maybe will fix it myself now), but when I started it up this time, it is mis-firing. It began right away, like a stuck valve. After running rough long enough to warm up, it's still not cleared up. Any suggestions to get 'er loosened up?

The heads were re-worked about 3500 miles ago, but as I said it has been sitting up, and the last time started was probably at least 3 months ago. Now I at least have it where I can get to it, and even work on it.

Should I try some Marvel Mystery Oil or something? Is there something that would have a more direct effect on it?

Thanks
 

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1998 T100 SR5 2WD
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If it's a stuck valve that yer suspecting...you might consider doing a compression check to see which one it might be.

Is the check engine light on? If so, what codes did you pull? ;)

It could be something as simple as a loose/leaking/broken vacuum line or something mechanical. You should take some piccies of the engine bay and post them up...we might be able to see something yer missing. ;)
 

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Discussion Starter · #3 ·
Thanks to all you guys for jumping in quickly with suggestions whenever anybody has a problem! I couldn't spend any real time with the truck this weekend, but did add some MMO and run it again. you can definitely hear a chuffing in the intake, so it sounds like a valve. Hopefully next weekend I can do some more extensive tests, like compression tests, etc. I gotta buy a code reader...

All-in-all, despite ongoing problems, I am glad to have my truck back in my possession, and will just do the work myself from now on. I had forgotten how much I love my T100, sick or not! :)
 

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'97 TC & '97 T-100
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Hello,

Mine has low compression in 3 of the 6 cylinders. Low compression is considered everything that lower than 15% of good ones. Readings are as follows:
#1 180; 185 wet;
#3 160; 190 wet;
#5 110; 125 wet;
#2 70; 80 wet;
#4 120; 145 wet;
#6 180; 205 wet
Wet compression check differ from dry by just adding a squirt of oil straight into a cylinder before you take a reading. That will give you a better indication,
whether your piston rings are any good.

It doesn't misfire after re-timing engine, however, it still causing rough idle & noticeable engine vibration.
I finally got to it, pulled valve covers & was hoping to see that there is no valve clearance at intake and/or exhaust valves at those cylinders with low compression.
If that would be a case, I prepared to adjust those shims to nominal valve clearance or little larger, but not smaller.
With my luck, unfortunately, it is not a case.

I guess I am at pulling heads off now & re-doing whole valve job, right?
 

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'97 TC & '97 T-100
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Mine has an exhaust valve on #1 stuck open. Has anyone tried to get one unstuck without pulling the head? This thing runs pretty good for a only hitting on 5 cylinders.
I wonder if you can bring that cylinder to TDC, release valve keeper & work that valve manually. Add oil there etc.
On the other hand, once you gonna be that deep in the engine anyways, might of pull whole head out (in case if you will have to replace valve or guide bushing)
 

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KS
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Yes a simple compression test would be the place to start if you are thinking its a valve.

However i would start by pulling the plugs to see if they each have spark. You can do it the old fashioned way by pulling the plug and grounding it out to see if you get spark while cranking, or get a tester, should be a few bucks. This way you can check the condition of the plugs.

also I would give it a shot with some seafoam in the intake, that can free up a stuck valve as well. I do mine via vacuum line from the brake booster.

How old is the gas in there?
 

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I wonder if you can bring that cylinder to TDC, release valve keeper & work that valve manually. Add oil there etc.
On the other hand, once you gonna be that deep in the engine anyways, might of pull whole head out (in case if you will have to replace valve or guide bushing)
Its stuck bad. It looks like I will have to pull the head to get it freed up. I might try to pull the exhaust cam and see if I can twist the valve stem and get it loose that way. I'll keep ya posted.
 

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'97 TC & '97 T-100
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Its stuck bad. It looks like I will have to pull the head to get it freed up. I might try to pull the exhaust cam and see if I can twist the valve stem and get it loose that way. I'll keep ya posted.
Don't forget to install service bolt onto exhaust cam before you pull it. It will save you some time later.
The rest is pretty much straight forward pain in the rear disassembly: exhaust manifolds, timing belt, etc.
 

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Don't forget to install service bolt onto exhaust cam before you pull it. It will save you some time later.
The rest is pretty much straight forward pain in the rear disassembly: exhaust manifolds, timing belt, etc.
I've had the exhaust manifold off twice on that side so it comes off fairly easy. Thanks for the reminder on the cam service bolt. I'll probably dive into it next weekend.
 

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1995 T100 2WD & 1993 MR2
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My 95 T100 has been sitting up due to a previously discussed transmission issue. I finally brought it home from the mechanic's shop yard (maybe will fix it myself now), but when I started it up this time, it is mis-firing. It began right away, like a stuck valve. After running rough long enough to warm up, it's still not cleared up. Any suggestions to get 'er loosened up?

The heads were re-worked about 3500 miles ago, but as I said it has been sitting up, and the last time started was probably at least 3 months ago. Now I at least have it where I can get to it, and even work on it.

Should I try some Marvel Mystery Oil or something? Is there something that would have a more direct effect on it?

Thanks
Sitting for 90 ays doesn't seem like a big deal but I'm curious to hear what would cause a valve to hang-up, especially after recent work being done so few miles ago!
 

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Sitting for 90 ays doesn't seem like a big deal but I'm curious to hear what would cause a valve to hang-up, especially after recent work being done so few miles ago!
I had a Yamaha TTR 230 that had been parked about that long and the stuck valve on it had what looked like tar on the stem. I tapped it out and cleaned it with carb cleaner and it was fine. It's still running strong. My theory is it was ethanol related.
 
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