Engine question

[nfpgasmask]

The "Alignment Mark on Timing Belt" (aka "dotted line") is suppsed to be lined up with the "Alignment Mark on Crankshaft Timing Pulley" (aka "green tick mark") which is 180 degrees from the "Groove on Crankshaft Pulley" (aka "notch") which is supposed to be lined up with the "Alignment Mark on Oil Pump" (aka "line on oil pump housing"). See image below.

OK yeah, this diagram shows it better. So how is it then that mine didn't line up that way? I mean, like you said, I removed the belt and put the new one on and I DID NOT turn anything while the old belt was off, so obviously I had no issues, same for Mark I am guessing. Is it possible that these reference marks are there for when you have the timing belt break and you need to get everything back right again? It's just weird to me, because when I turned the motor over by hand with the old belt on, the notch in the pulley always ended up at the 9:00 o'clock position when the LH Camshaft pulley and RH camshaft pulley were in the right spots....

Bart

[MSHardeman]

YEP, Bart, I followed your instructions and everything seems to be working for me too. When the left and right hand cam pulleys where lined up on their marks, the mark on the crank pulley was lined up with the mark on the engine and the notch on the pulley was 180 degrees away from that. Installed the new belt (Isuzu) with the marks on the cam pulleys lined up and the dotted line lined up with the notch on the crank (again 180 degrees from both the mark on the crank pulley and the engine case). I do remember reading something, somewhere on how to get your timing back if your belt broke and completely threw everything off, just can't remember where.

BTW, Bart, could you make some space in your PM box? Can't respond b/c it's full.

[nfpgasmask]

YEP, Bart, I followed your instructions and everything seems to be working for me too. When the left and right hand cam pulleys where lined up on their marks, the mark on the crank pulley was lined up with the mark on the engine and the notch on the pulley was 180 degrees away from that. Installed the new belt (Isuzu) with the marks on the cam pulleys lined up and the dotted line lined up with the notch on the crank (again 180 degrees from both the mark on the crank pulley and the engine case). I do remember reading something, somewhere on how to get your timing back if your belt broke and completely threw everything off, just can't remember where.

Yeah, I know the Isuzu video shows both the timing belt change if the timing is good and the timing belt change if the timing is broken. But yeah, what you described above is exactly how mine was.

BTW, Bart, could you make some space in your PM box? Can't respond b/c it's full.

Done, thanks.

Bart

[Scott Larson]

So confused! I followed Bart's how-to after perusing all the other how-to's on the subject and had no issues/questions whatsoever...great tech write-up Bart!! Still curious about the "Chocolate Monkey" though...

[nfpgasmask]

Still curious about the "Chocolate Monkey" though...

That was inserted by Tom, you'll have to ask him...

Bart

[SlowPro48]

Yes, Scott, it IS a great write-up. In fact I think it's the best I've ever seen as far as attention to detail, how methodical it is and of course all the pics are very helpful - so Bart I hope you don't think I'm picking on your How-To. Burlington Buffy asked if he had his shyte lined up right and I just pointed out it's 180 degrees from what Isuzu says to do. I've already presented my hypothesis as to why it works when lined up with #2 and #5 at BDC instead of at TDC like the manual says they should be - but I'll leave it up to someone else to come up with a definitive answer - or for all I care it can remain a mystery like that thing hovering in the back yard when I was a kid or the strange, strange pond with sides like glass in the woods near here....

That is all.

[nfpgasmask]

SlowPro, not at all. For me, it's just that I want my how-to to be correct, accurate, concise and NOT confusing. Most of all, I don't want to point anyone in the wrong direction and have them eff up something with their VX.

The "chocolate monkey" thing might just do that (), so I always point people to the original how-to here:

http://www.nofuture.com/myvx/how-tos/tb/tbelt.htm

The above link is from my website, and if I make any revisions, you will see them there, but not in the PDF that Tom made of my original how-to back when I originally posted it. In fact I do think there are some minor changes on my site that ARE NOT in the PDF currently. Plus, I think my website is a better format and easier to follow. While the PDF is easier for people to find, I encourage everyone to visit the instructions on my site over the PDF.

I think the most confusing part for me now, is I sit here wondering what would have happened if I was to:

A) remove the tensioner
B) remove the original belt
C) turn the crankshaft pulley to move the notch to the right side, aligned with the mark on the oil pump housing, with the green line on the top of the pulley on the other side
D) put new belt on

Would my timing be OK or off? It's just so weird in my head because with the original belt still on, when I turned the crank shaft pulley to align the LH and RH camshaft marks, the notch was ALWAYS at the 9:00 o'clock position and the green line always lined up with mark on the oil pump, so I figured I had it right.

Personally, I think the Isuzu shop manual sucks. It's vague, the illustrations are terrible (they look like 10th generation photo-copies), and it assumes you have been a mechanic for 25 years (can't fault them there though).

Are there any other folks besides Mark who have done the timing belt change themselves? I'd be curious to know how things look for different people. SlowPro, you did the swap yourself and aligned the notch in the back of the crankshaft pulley with the mark on the oil pump. So, when you did it, did your marks on the LH and RH line up as well? So weird.

Bart

PS - I started working on a new how-to for the tranny fluid change but my camera's flash crapped out in the middle of doing it.

[Buffy]

I wondered the same thing. I would think that you would want to pull a valve cover and see if the cam timing marks are lined up. If they are I would think you could do that. I am just going off what was said in the "Lost Timing Reference" video on the web. My passenger cover is only sitting on the head so I may back the pulley to the reference mark on the cover, pull off the cover and see if I see the cam timing marks.

[Scott Larson]

[QUOTE for all I care it can remain a mystery like that thing hovering in the back yard when I was a kid or the strange, strange pond with sides like glass in the woods near here....

OMG, you saw that too!!!

[psychos2]

I think the most confusing part for me now, is I sit here wondering what would have happened if I was to:

A) remove the tensioner
B) remove the original belt
C) turn the crankshaft pulley to move the notch to the right side, aligned with the mark on the oil pump housing, with the green line on the top of the pulley on the other side
D) put new belt on

Would my timing be OK or off? It's just so weird in my head because with the original belt still on, when I turned the crank shaft pulley to align the LH and RH camshaft marks, the notch was ALWAYS at the 9:00 o'clock position and the green line always lined up with mark on the oil pump, so I figured I had it right.

from what has happened to some on this site and from what I have read about getting the cams back in time if the belt breaks.
1st make sure the marks are lined up before removing the belt.
2nd don not turn the cams without the belt being on. if you were to turn the cam 1 turn and put the belt on the cam timing would be off.There is a TSB about retiming the cams take a look at it and it will answer the question as to what would happen. shawn

[Scott Larson]

For what it's worth, you can turn the cam sprockets all you want, just don't lose track of how much you move them from the initial timing marks. I rotated both sprockets to tension the cam lobes against the valve springs to aid in setting the belt to correct time. (It eliminated the need for a helper or breaker bar and bungie cords to hold them from their 12 o'clock off-lobe position as per Barts write-up.) Set the belt to the correct position on both cam sprokets and then rotate the sprockets back to time, tensioning the belt in the process.

[psychos2]

For what it's worth, you can turn the cam sprockets all you want, just don't lose track of how much you move them from the initial timing marks. I rotated both sprockets to tension the cam lobes against the valve springs to aid in setting the belt to correct time. (It eliminated the need for a helper or breaker bar and bungie cords to hold them from their 12 o'clock off-lobe position as per Barts write-up.) Set the belt to the correct position on both cam sprokets and then rotate the sprockets back to time, tensioning the belt in the process.

If the cam is out of time it can take up to 9 full turns to put it back in time.So if you were to turn it 1 full turn the cam would be out of time.Yes you can turn it a little to line up the belt but I would not move it anymore than that unless you want to make alot more work for yourself. shawn

[tom4bren]

The "chocolate monkey" thing might just do that (), so I always point people to the original how-to here:

http://www.nofuture.com/myvx/how-tos/tb/tbelt.htm

The above link is from my website, and if I make any revisions, you will see them there, but not in the PDF that Tom made of my original how-to back when I originally posted it. In fact I do think there are some minor changes on my site that ARE NOT in the PDF currently. Plus, I think my website is a better format and easier to follow. While the PDF is easier for people to find, I encourage everyone to visit the instructions on my site over the PDF.

Yerrrr Welcome!!!

I tried to be true to Bart's write up when I converted it to PDF (only took a little comic liberties). In retrospect, I should've added a hyperlink to his website so that any updates could be tracked. The PDF isn't supposed to do anything more than provide a copy for peeps to archive if they wish & print a throw-away copy to have in the garage whilst doing the repair.

Back on topic: Take the pix of the timing mark alignments to an authorized Isuzu repair facility (yes, those still exist) & find out if it appears out of spec to them.

IMHO, although the mark is obviously off slightly, it's not off by the amount that a 1 tooth adjustment on the belt would correct. If you adjust the belt by 1 tooth, the mark may actually be on the other side of the reference. This makes me think that it's a tensioner issue.

BTW, Chocolate Monkey:

[Ldub]

IMHO, although the mark is obviously off slightly, it's not off by the amount that a 1 tooth adjustment on the belt would correct. If you adjust the belt by 1 tooth, the mark may actually be on the other side of the reference. This makes me think that it's a tensioner issue.

Take a close look at the pic in question...the camera isn't lined up square with the end of the cam, giving the appearance that the reference mark is slightly off.
If the camera moved left slightly, so that the cam sprocket bolt was in line with center, everything would line up just right.

[MSHardeman]

When I helped Joh (VXorado) do his timing belt, his cam looked just like the picture above. We sat there and pondered whether his timing was actually off, or not, for a couple of hours. We moved the cams one tooth back and forth, but the marks never seemed to line up perfectly (they where that way with the old belt on too). In the end he left it, put it all back together, and it's been running just fine ever since.