Hi,

I have a 98 Neon DOHC auto and I'm having trouble with the timing belt. The timing belt broke on the engine forcing me to replace the head which I did.
After getting everything put together, it seemed to run fine with the exception that it stumbled every so often.
After my 3rd time out testing I got a CEL warning of P1390. This makes sense because it does feel like the timing may be off ever so slightly.
It says it may be off 1 tooth or more, judging by how well it runs, I'm assuming it is probably 1 tooth off.

The question, how do you know which way to move the timing belt 1 tooth forward or 1 tooth back. What is the best way to determine how to properly place the belt.

When we installed the belt in the first place we made sure we aligned everything as indicated by Mitchell's and Chilton's turned it over a few times manually and everything seemed to line up properly.

But having done all that I guess we were slightly off. So I don't want to take it further out out time.

1 tooth forward or back??

Thanks

 

There is no 1 tooth adjustment option. You basically have to do it again. Sorry.

What probably happened is that did not have the bottom pulley 1/2 tooth (3deg BTDC) behind the mark on the block when you put the belt on and so when the belt was put on and the slack removed and tensioned, you were off by at least that much. That happened to me twice while I was getting the hang of putting it on as it does take a little bit of skill to get it right.

Either that, or it was not properly tensioned the first time and when you put it under a load, it slipped.

In any case, you have to redo the whole job anyway if it is truly out of time. There are no tweak a tooth options that I know of.