Reset Timing

[Marke525]

I just replaced my timing belt and water pump. The problem is that the idle is rough and idling low (550 rpm). I think the problem may be one of the cams is not aligned properly.

My question is how do I check to make sure the cams are aligned properly? One has a timing mark and I thought the other one had one, but it was very faint. If the timing mark isn't there, is there an other way to make sure the cam is aligned correctly?

[landar]

I just replaced my timing belt and water pump. The problem is that the idle is rough and idling low (550 rpm). I think the problem may be one of the cams is not aligned properly.

My question is how do I check to make sure the cams are aligned properly? One has a timing mark and I thought the other one had one, but it was very faint. If the timing mark isn't there, is there an other way to make sure the cam is aligned correctly?

I do not believe there is any way to check other than removing the cam pulley covers to inspect the marks on the pulleys themselves.

The mark has a slight indentation that you should be able to find. Then you can re-mark it with some paint or something.

I would think that running rough because of cam timing would throw a code. What year do you have?

[Marke525]

It is a 1992 LS400.

Thanks for the input. I ran it for a couple minutes and the check engine light didn't turn on, but I'll check with the code reader anyway. I figured since it runs but not well that the timing being off a tooth would be most likely. I'll keep you posted.

[RDM]

The first 1UZ timing belt I ever did the crank gear was off one tooth, the check engine light didn't come on until the customer had picked it up and driven it home, about 20 miles. Often times the ECU stores a fault but won't trip the light until it's certain there is a problem. I'd verify the marks and reset the belt anyway since it's probable that's the issue, there's not a lot else you could do during a belt job that would cause erratic operation.

[Marke525]

The first 1UZ timing belt I ever did the crank gear was off one tooth, the check engine light didn't come on until the customer had picked it up and driven it home, about 20 miles. Often times the ECU stores a fault but won't trip the light until it's certain there is a problem. I'd verify the marks and reset the belt anyway since it's probable that's the issue, there's not a lot else you could do during a belt job that would cause erratic operation.

Thanks for the reply. I'll start tearing it apart this weekend, again :cries:

[landar]

The first 1UZ timing belt I ever did the crank gear was off one tooth, the check engine light didn't come on until the customer had picked it up and driven it home, about 20 miles. Often times the ECU stores a fault but won't trip the light until it's certain there is a problem. I'd verify the marks and reset the belt anyway since it's probable that's the issue, there's not a lot else you could do during a belt job that would cause erratic operation.

Thanks for the reply. I'll start tearing it apart this weekend, again :cries:

Look for some simple things too. Like the distributor caps/rotors and wires. Maybe something is not quite right in that department.

It is not uncommon for those items to give problems after being disturbed. Double check vacuum lines, sensor connectors (and connections).

Hopefully, you changed the caps/rotors while you were in there?

[Marke525]

The first 1UZ timing belt I ever did the crank gear was off one tooth, the check engine light didn't come on until the customer had picked it up and driven it home, about 20 miles. Often times the ECU stores a fault but won't trip the light until it's certain there is a problem. I'd verify the marks and reset the belt anyway since it's probable that's the issue, there's not a lot else you could do during a belt job that would cause erratic operation.

Thanks for the reply. I'll start tearing it apart this weekend, again :cries:

Look for some simple things too. Like the distributor caps/rotors and wires. Maybe something is not quite right in that department.

It is not uncommon for those items to give problems after being disturbed. Double check vacuum lines, sensor connectors (and connections).

Hopefully, you changed the caps/rotors while you were in there?

I did change the caps and rotors. I hadn't thought about double checking the vacuum lines and electrical connectors.

I'll start there. Thanks for the thought.

[curiousB]

Make sure you have the proper marks on the gears aligned to the new belt markings. For some reason Toyota chose to put unrelated markings near the important ones leading to possible confusion. This link has photo's, not sure it’s the same model as yours but still may be useful.

http://www.flickr.com/photos/landar/413860...57622886015670/