Rough Running after Timing Belt Install

[kpaske]

OK, I've finally completed my Timing Belt install, but I think I've got a big problem! After it warmed up for a few minutes, the engine runs fairly smooth, but the check engine light is on, and the exhaust is back-firing and smells WAAAY too rich. I took it for a very short drive, and it feels hesitant upon acceleration and there is a lot of vibration when it's in gear.

I'm pretty sure my timing isn't out of phase - I followed the directions that VCrossfan provided me, along with Randy's HowTo, and I thought everything went fairly smoothly. I'm really hoping that maybe the computer just needs some time to readjust, but I don't want to run it too much without consulting the experts here.

Please, any advice would be appreciated.

[raver_boi_88]

well your timing could be off but if it isnt then mabee you have a bent valve? Did you actually break the belt or was it just that time of year to replace it? I know when I broke mine, I had a simalar problem and I had to replace both my timing belt, and three valves...

[kpaske]

I was just doing the standard maintenance. In fact, my original timing belt appeared to be in pretty good shape.

I'm pretty sure I lined up the timing marks how the directions indicated. I really hope that isn't the problem or else I'll have to do the whole job over again. ARG!!

[kpaske]

Just so I'm clear, let me describe how the marks lined up. If you are looking at the motor, and the top center is 12 o'clock, the passenger side pulley lined up at the 10 o'clock mark, and the drivers side and crank shaft pulley's both lined up at the 2 o'clock. Is this right?

[Joe_Black]

Since the 6VE1 is a non-interference engine you at least don't have to worry about bent valves. The timing belt removal/replacement is pretty clearly outlined in the shop manual, including the timing reference marks.



Number 8 on the diagram is a blow-up of the reference marks for the camshafts, numbers 2 and 5, while number 7 is a blow-up of the timing mark for the oilpump shaft, number 1. All three should align to those marks.

Also note, from the manual: When timing is performed, the number 2 piston will be at TDC.

When changing the timing belt the battery should have been disconnected (for safety) which would force an ECU reset as well.

Check your timing against the reference marks and let us know your findings. Good luck!

[kpaske]

Joe -

Yes, I think that is how I did it. The only part that looks unfamiliar is item 8 - I didn't line anything up on the left side of the cam shaft pulley, I just located the notch on the pulley (I'm pretty sure there was only one), and it lined up exactly with the mark at number 7.

Now the instructions mentioned having to crank the pulleys around several times (up to 9) in order to get them to line up. My cam shaft lined up after one rotation. The driver's side took about 3 or 4 full rotations, and the passenger side lined up after 1 or 2. When I say they "lined up", they sort of "popped" right into place.

I really think I lined it up correctly, and the diagram you just showed me is reassuring (because I felt the guide I was using was a little vague about where to line up the passenger side pulley). So why does my VX run so crappy now?? I've had a dead battery before - probably for a week or more when I was out of town - but I'm not sure if it was dead enough to reset the ECU. When I removed the battery to have it tested and recharged, it was probably disconnected for several hours. It didn't seem to have any issues readjusting then, and that was only a few months ago. The only real difference is that the whether was warmer, but this past week hasn't been too bad. This time I had the battery disconnected for about 4 days, so I know for sure that it should be reset. Should I just let it run for 15 or 20 minutes, or do I need to start driving it around? Is it most likely just going to improve with time? The vibration and back-firing have really got me worried.

Kyle

[kpaske]

Vcrossfan - You're absolutely right - the instructions you used never made mention of the left side alignment marks on the crank shaft pulley. A little bit confusing when compared to the Isuzu shop manual, but as I said before, I think if you flip the belt upside-down, it would line up correctly that way. The actual mark on the crank shaft pulley is very hard to see, but it's there. As you can see from the diagram above, #8 is a blow-up of the marks on the belt, showing where they should line up. The stock belt has a dotted line instead of the Gatorback's double line, but other than that, everything else is identical.

Just an update for you guys... I took it to a local repair shop, where they've torn it down and put it back together several times. They can't figure out the problem either. They're telling me that all three cylinders (1,3,5) are NOT firing. They've got spark, they've got compression (190 lbs I think they said), but nothing is happening on that side. Can anyone here explain that one??? I'm baffled...

[Amnesia]

SOLUTION outlined:
I have around 222,000 miles on my VX and had previously replaced my belt twice with no issues. The 3rd time I recently replaced my belt, I ran into this issue. The FSM / CD have the procedure wrong. Apparently the 3rd time I did it, I deviated (or followed too closely) the instructions about rotating the cam sprockets up to 9 times to get them in the correct position... I found a video on youtube that outlines the correct phasing procedure.

In a nutshell. Line up your crank as indicated. Line up the notch on the passenger cam pulley as indicated, by rotating until the notch "snaps" into place at the 12'oclock position and lines up with the mark on the cyl head. BUT... BUT - the passenger pulley MUST be rotated until it "snaps" into place with the notch at the NINE o'CLOCK position. THEN rotate it an additional 90' clockwise until the notch lines up with the mark on the cylinder head. Now install the belt as indicated and all will be well.

And yes, the job goes MUCH faster the 2nd time through!

Hope this helps!

[Scott Larson]

This was all covered in Bart's timing belt replacement write-up years ago, you do realize that you're responding to a thread that is over six years old...Just sayin'.

[Amnesia]

I didn't do a search, but figured even if it had been covered elsewhere - it couldn't hurt to add a final resolution here for those that find this first. More places it's mentioned, the better the odds of someone coming across it I figure.

[Scott Larson]

You've got a good point there, my bad...

[Greasemonkey]

Just to give a good tip -
Line up the crank to TDC using the timing marks on the out side of the oil pump which is a notch and the cut out on the inner side of the crank sprocket then mark the cams with tip-ex correction fluid - this way you know they are spot on - I also mark them in three places along with the crank sprocket - when removing the old belt push the long section of the belt in hard using a lever and pin the tensioner - then remove the tensioner - the cams will flick round once the tension is removed - but try to let them loose slowly using a spanner on the cam bolts - use bulldog clips or clothes pegs to hold the new belt in the right place on each cam and cable ties on spanners to hold them against the springing action works great - fit the tensioner and pulley assembly to the right torque and lever the new belt to release the pin on the hydraulic tensioner - turn over three times jobs done
cheers
Steve
PS removing the power steering pulley helps with removing the timing covers too