Jump Timing and the causes

[Hondasi88]

Ok i have a problem my car keeps on jumping timming.The balance Shaft belt is fine ......but the camshaft to crankshaft timming belt even though properly tensioned keep jumping
what can cause this?

The timming marks keep switching what the hell is going wrong?

 

[PieEyedPiper]

Hmm, its gonna be hard to say.
Old belt?
Cracking belt?
Stretched belt?
Bad tensioner?
Incorrect tension?

When is it jumping? Once a month? Everytime you start the car? Have you bent any valves? What are the condition of your belts, pulley's, tensioners, and cam gears?

 

[Hondasi88]

New belt
New rebuilt head
New water pump
New balance shaft belt
all new belts

new tensioners........................ All the marks are fine i just timming this time by just starting up the car for a few. I heard some grinding noise in the head area but everything checked out so I finally pulled the mount and cover and again the timming was way off.

 

[acsbmx_1]

How far off does the timing have to be before the valves get bent? If its more than one tooth your probably bent the valves again. I had this same problem. I'm still in the same situation you are kind of, but my car wont start and run. Did you follow the Tech Article on vfaq.com for replacing the timing belt?, and tensioning? Or did you have someone do the timing for you?

 

[FORMONTOYA]

You mentioned new tensioners.....does that include the tensioner pulley? If so, one of the things I noticed that was always missing from the VFAQ (it alludes to it, but doesn't specifically mention anything about it) and SHOULD be there for pulley replacement:

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This is one of the "extra" things I do during a TB job.

 

[talonTSIDriver]

I am having that exact same problem with my talon project. I replaced everything, timing belt, all the tensioner pulley's but one thing I did not replace is the hydraulic tensioner. I out it in a vise with little tension, and after a little while it will go in. I am 99% sure that's the problem. I would recommend you check that out as well.

 

[laserspeeddemon]

You mentioned new tensioners.....does that include the tensioner pulley? If so, one of the things I noticed that was always missing from the VFAQ (it alludes to it, but doesn't specifically mention anything about it) and SHOULD be there for pulley replacement:

You must be logged in to view this image or video.

This is one of the "extra" things I do during a TB job.

Ah damn it, I drew a picture. By the time I got it drawn you had posted yours.

 

[laserspeeddemon]

Oh don't forget to retension the belt after about 1500 miles. New belts will stretch

 

[FORMONTOYA]

Ah damn it, I drew a picture. By the time I got it drawn you had posted yours.

I usually "lose the race" because someone comes around and wants me to actually work at my job in stead of "jacking around" on the net (imagine that). You guys are actually lucky (???) that we observe NWS....otherwise I'd be looking at porn 8 hours a day.

 

[90_EAGLE_TALON]

My car is doing the same thing. I have had to rebuild my engine 3 times in less that 250 miles. The timing was installed corretly and the auto tensioner replaced each time. This time I am also replacing the idler pulleys. Do you think that this will solve my problem? My car also has the balance shafts removed.

 

[steve]

Note that in both the diagram and the picture the holes are shown in the starting position before the belt is actually tensioned (pre-loaded). When you tension the belt you will be rotating the holes either above or below the bolt depending on if it's a 6 bolt or a 7 bolt (or maybe its a 1G or 2g, I forget).

Steve

 

[toybreaker]

^^^^Excellent suggestions^^^

I especially like the picture of the tensioner pulley showing the correct starting orientation of the two adjusting holes. Getting the correct amount of belt wrap around the cams is very important.

I had a few thoughts on some other things to check, as well.

Do the camshafts turn freely? I could see how there could be some skippage if the cams don't turn nicely. To verify that they turn nicely, without causing additional trauma, we've got to get the pistons out of the way. With the t-belt off, if you are starting at tdc #1 on the crank and cams, turn the crank backwards (counter clockwise) until the keyway on the crank is at about ~9 o'clock. Now the pistons can't be hit by the valves, and the cams can be rotated freely. Spin them (one at a time) all the way around a couple of times with a 17 mm socket and a ratchet on the cam gear bolts. Beware, they will get easier/harder to turn, and on the backside of the lobe, they'll have some energy stored up, and will try and jump away from you. If the cams don't spin well, pull the valve cover and inspect the cam caps. Are they installed in the correct locations, facing the correct direction? tease: I've done that, and I've also mixed and matched parts from other heads,, I mean I've seen it done....)

While the valve cover is off, inspect all the other components.

If the cams turns well, lets turn our attention to the oil pump/rear balance shaft. It should turn fairly freely by hand, but the definative test is with a cordless drill. Chuck up a 14mm socket in your drill. Spin the oil pump drive clockwise at a moderate speed. You'll hear the drill bog down as it starts moving oil, but it should be able to spin the oil pump drive at a reasonable speed. You can verify oil delivery to the head if you have the valve cover off when you do this. (You will also make a mess if you don't cover the little bleeder holes at the end of the lifter rail with your fingers, as oil will geyser up out of them.) or so I've been told... )

Please, do not use an impact, or even an air ratchet to turn the pump. Due to the resistance of pumping the oil, you can seriously overtighten/snapperfy the oil pump nut/drive stub using power tools.

If the pump doesn't turn well, it could be a pump issue, or it could be a balance shaft issue. (For those of you that still have them.)

If the pump turns nicely, you're going to have start examining the individual components, one by one.

Are the teeth worn on the timing gears? This can happen from running with the covers off in dusty climates, as well as on higher mileage motors.

Are the timing cover gasket strips all accounted for? You know, those little strips in the cover that seal the cover against the motor. I could see how you could skip a tooth or two if they got in between the gears and the belt.

Good luck, and let us know what you find.

 

[Hondasi88]

Thanks for all the replies.........actually my friend is doing the job for me and believe me he checked EVERYTHING! I am printing this out and the write up on the tech files so he can look thing over. I told him to just reg and post so he can ask all the questions directly.

 

[Hondasi88]

A little update so i went out and bought everything new from mitshi.......all the timming tensioners and pulleys so we will see what happens.