J30 timing belt problem

[trissdv]

I have a couple of questions. Myself and my roommate who has mechanic experience have been trying to change the timing belt on my '94 J30. I got it used, and don't have much in the way of it's service history, but at 113k miles (got it at 103k) I'm going to assume it was time for the timing belt to be changed, possibly way passed due. And in fact there was a hole eaten in the middle of it so good thing too! My questions will follow in the later portion of this post.

Anyways the roommate is the one doing most of this, my knowledge is limited, and he didn't take a lot of precautions when tearing everything apart since he's familiar with the procedure (I'm sure just with domestic brands mostly though). We've tried several times to get this to work but the timing hasn't been right. Someone did paint some marks on it, and has been in the engine before he is certain. We finally got the belt on at what we thought may be right, and the car starts but idles high now with occasional dip and surge and when accelerating it sputters and acts like it wants to stall after letting up on the gas. I haven't put it on the road, it's still jacked up, so this was just testing. Now come to find out someone thinks it may have a '93 engine in it for whatever reason and says the belt is entirely different and longer. Things no matter what, if lined up with the marks ON the belt is a tooth off. He claims he let it be off one tooth but kept the mark on the sprockets and back cover lined up for that almost successful attempt.

We got the belt for a '93 and are trying that but ran in to the same problem. It isn't any longer it seems and still wants to be a tooth off. This time he's putting it together with the marks on the belt matching the sprocket, but one sprocket being a tooth off from the back cover to see if that's any better. This way the tooth count as laid out in the procedure found here and what is in the instructions is correct.

First, is there any way to tell what year the engine is? Second, does anyone have any insight about the timing? The marks don't line up, so what can be recommended? Thanks!

[Mkiisupra]

Your roommate should have paid attention to what he was doing when he took things apart. There is only 1 timing belt for the engine no matter what year. There are marks on the cam gears and the timing covers to set the timing correctly. Line them all up properly or you may damage the engine. You might consider finding someone who actually knows what they are doing. I replaced the timing belt and water pump on my 95 just a few months ago, I assure you the timing marks do line up when you do the job properly.

[trissdv]

The part number at every parts store I've checked is different for a belt on a 93 and a 94. If they are the same belt then why a different part number?

Also having used belts listed for either year, no matter what, the sprocket and mark on the cover either must match up with eachother and not the marks on the belt, or else one must match with the belt but not the other, on my particular J30, regardless of however else everything else was done. It absolutely can't match each other and the marks on mine. Matching the sprocket to the cover (and not the mark on the belt) did not work previously. We've now advanced it one tooth so it matches the marks on the belt and the car runs fine. This was also the only way to get a proper tooth count between sprockets as listed in the procedure and on the instructions included with the belt. The only issue is he thinks it is not running with quite as much accelerating power as before. I'm going to take it around tomorrow and see for myself. We did also clean the MAF and throttle bodies, so he said it's possible that the sensor was causing it to run too rich before and the amount of accelerating power currently is what it's supposed to be at (not that it's running poorly, just less ballsy)

[trissdv]

I've also read of some other J30 owners having to advance the timing by 5 degrees when changing their belt, I can point out one instance specifically on this forum. So I can't say that it's incorrect. But if there are any other adjustments (cam angle sensor...etc) that might need to be done, any advice is helpful.

[yodawill2000]

the 93 J30 and the Z32's came with a 60K belt. 94J and up came with a 115K Kevlar belt. Thus the different part #'s.
Did he make sure the dots on the sprockets lined up "After" tightening up the tensioner ?
I found that when tightening up the tensioner, the passenger side sprockets would turn one tooth counter clockwise.
If i set the sprockets one tooth to the right before tightening , everything lined up spot on.
Also make sure the crank sprocket is lined up proper.

[jester4666]

the 93 J30 and the Z32's came with a 60K belt. 94J and up came with a 115K Kevlar belt. Thus the different part #'s.
Did he make sure the dots on the sprockets lined up "After" tightening up the tensioner ?
I found that when tightening up the tensioner, the passenger side sprockets would turn one tooth counter clockwise.
If i set the sprockets one tooth to the right before tightening , everything lined up spot on.
Also make sure the crank sprocket is lined up proper.

that is some good information. my car has 203k on it and i'm not sure when the belt was changed on mine. might be something that i'll look into.

[trissdv]

the 93 J30 and the Z32's came with a 60K belt. 94J and up came with a 115K Kevlar belt. Thus the different part #'s.
Did he make sure the dots on the sprockets lined up "After" tightening up the tensioner ?
I found that when tightening up the tensioner, the passenger side sprockets would turn one tooth counter clockwise.
If i set the sprockets one tooth to the right before tightening , everything lined up spot on.
Also make sure the crank sprocket is lined up proper.

That's really good to know. I wasn't with him when he last tightened the tensioner, and I recall him saying something to that affect, so I'll double check. But I think you are absolutely correct that it probably happened that way. Thank you for the good info.

[trissdv]

So I have a new issue after having gotten the timing belt on. I have tried explaining this to the friend who'd put the new belt on but he doesn't seem to understand what I mean, and I don't know in any sort of mechanical jargon of what to say or understand exactly how to phrase it to him.

Previously when the gas pedal was floored while driving, after about a second or so the car would shift itself (around 4000 to 5000 rpms) with what I describe as just a small little jerk, the engine would have a somewhat deeper rumble, and it would really start hauling while maintaining a reasonable rpm. It just felt like the car had more power to it, a pull of sorts. It was ideal for climbing hills especially. NOW when you press the pedal fully all it does is raise the rpms and the engine sounds high. It hit about 6500 before I let up. In normal driving conditions (not flooring it) it is shifting itself, just not when you floor it. It gains speed just fine still. He claims it seems to be working fine, but -I know- it is not working the same. Not as powerful.

Other than that it purrs, it idles great, there is no issue that would indicate the timing is off. All we did was change the timing belt, idlers, tensioner, and cleaned the MAF and throttle bodies.

[trissdv]

Of course I could be entirely wrong and maybe previously the car wasn't functioning how it should be and now it is (the friend maintains this is the case). But since I was getting what seemed like way more engine power from flooring it after whatever it was engaged, it just doesn't seem logical.

[yodawill2000]

You may need to check the codes on the ecu to see if your getting a knock sensor code.
If its bad it will retard timing up to 3K.
If you stomp on it you will feel the torque kick in right about at 3K rpms.