Rough Running after Timing Belt Install

[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

[Joe_Black]

I'm beginning to think one of your cams is out of time. Each cam has a "number 8" reference mark, where the "number 7" in the diagram is for the oil pump shaft (number 1). Did you verify that the #2 piston was at TDC when you rotated the cams to time? That's the crank reference. With all the backfiring and rough running you could have maybe two pistons out of time even, hopefully though it's just a pair of valves. I'm not intimately familiar with the 6VE1's sequence so am just generalizing.

If it were me I'd re-time from scratch using the Service Manual procedure, letter for letter.

[kpaske]

Each cam has a "number 8" reference mark, where the "number 7" in the diagram is for the oil pump shaft (number 1).

Joe, I don't understand what you mean here. The marks that I lined up were:

On the passenger side cam pulley there was a line on the front with a little bit of green paint on the edge. I lined this up with the mark on the block at about 10 o'clock.

On the driver side cam pulley there was also a line etched on the front with green paint on the edge. I lined this up with the mark on the block at about 2 o'clock.

The crank shaft pulley didn't have marks on the front, but a single notch on the back edge of the pulley. I lined this up with the mark on the block at about 3 o'clock.

To line these up, I basically just cranked them clockwise until they "popped" into place, meeting the mark exactly.

Did you verify that the #2 piston was at TDC when you rotated the cams to time? That's the crank reference.

What is TDC, and how would I verify this?

With all the backfiring and rough running you could have maybe two pistons out of time even, hopefully though it's just a pair of valves. I'm not intimately familiar with the 6VE1's sequence so am just generalizing.

If it were me I'd re-time from scratch using the Service Manual procedure, letter for letter.

Well, that's what I have to do if that is really the problem. I just need to understand what my mistake was so that I don't repeat it. I thought I had followed the instructions exactly...

[mbeach]

I gave advice based on this paragraph:

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.

The point is, you turned various shafts independently of each other. It's too easy to miss the mark this way. If you want to spend days moving your cog(s) one tooth to the left/right than that's fine.

Here's another thought:
Where'd you get your replacement belt? If it's too long (would you know?) then it doesn't matter what you did right, your timing will wander from spec.

The RLTW was not a dig -I recall you mentioned that you were in 2d Batt before. I was being courteous.

[kpaske]

So if it is, in fact, 180 degrees off, it should be relatively easy to put it back in phase, right? I'm guessing that one cycle of the #2 cylinder is what it would take? In other words, rotate the drivers side cam until the piston moves from TDC, to the bottom, and back to TDC?

I don't think I'm one tooth off though - I took extra care to ensure that everything looked exact, and lined up the double line on the belt with the mark on the crank shaft pulley, leaving little doubt. I drew a little line on the belt tooth that corresponds to that mark so it would be easy to see when it lined up, and the lines on the cams line up fairly easily. Also, the cams sort of "pop" into place, so I think it's hard to screw those up.

The belt is a Gatorback, which is what several other members have used, so unless it is defective, there shouldn't be any issues with fitment.

If you guys are pretty sure it is 180 degrees off, if you could just confirm what the best way to make absolutely sure everything is lined up correctly, I've got no problem tearing it down and putting it back together. Third time's a charm, right?

P.S. Mbeach - I didn't think the "RLTW" was a dig, I just wasn't sure if there was some other meaning to the acronym, as I didn't think most people knew it to mean what I know it to mean. I'm surprised you remembered I'm with 2nd Bat.

[psychos2]

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.

i was looking at the cd manual and noticed what you had said in an earlier post.the reference to 8 in the diagram is for the crank not the cam pulley.and i also noticed that in the manual it says to make sure the writing is facing so you can read it from the front of the vehicle.so my question is did you line the crankshaft mark on the belt to the drivers side or the passenger side of the motor? because you line up the mark on the drivers side with the mark on the crank pulley and then you line up the mark on the belt with the mark on the passenger side of the crankshaft gear.
do not know if this is what you did ,but i was confused when i first looked at the diagram.hope this helps shawn

[kpaske]

Yeah, I meant to say the crank shaft pulley... I'm not sure if I did it right the first time around, but the second time I'm positive that everything was lined up correctly. On the gatorback, there is a double line that lines up with the 9 o'clock position of the crank shaft pulley, and two single lines that each line up with the marks on the cam shaft pulleys. I'm beginning to think that maybe I had a defective tensioner, but at this point I'm so busy I really don't have much time to screw around with it. I'm going to take it to a shop and get it fixed, but I'll be sure to give everyone an update on what the problem was, so nobody else runs into a similar problem if they try to tackle this job themselves.

[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...

[Dare2Dream]

This is probably not much help, but maybe you should just try the OEM belt to reduce any 'possible' doubts with the gatorback. Obviously, gatorback has worked fine for others, maybe you just have a fluke!

[VCrossfan]

Good Idea Dare2Dream..I did have a friend that installed a non-OEM timing belt (not sure the brand) and the timing/alignment marks on the belt weren't even close. It was several years ago..but it does happen...