Hi Guys!

I have a stock 1998 GS Automatic, and I have problems. It takes 12 seconds to reach 0 to 60 mph. I think it's too slow, even for a GS auto... correct me if i'm wrong. I think there are problems with the ignition system, but i don't know which part gone bad. I hooked up an OBDII reader with the digimoto software. It says that the ignition timing advance is at 6 degrees constant, or it's moving randomly between 2 - 8 degrees at idle. The service manual says that it needs to be 12 degrees constant at idle. There are no trouble codes at all. I changed the timing belt, bearings, hydraulic tensioner, water pump, and the timing marks are aligned correctly. I changed the spark plugs, the ignition coil pack, spark plug wires, and the problem is still unsolved. I suspect one or more sensors. Any ideas? What should I change, or repair? I hope I don't need to change all of the sensors to get this solved.

The second problem is that the idle speed is unstable. It's "jumping" rapidly between 550 - 850 RPM, and this "jumping" effect comes, and goes out randomly. The engine starts fine, never had any problems starting it, cold or warm engine, it doesn't matter. After the cold startup mode ends (the RPM falls below 1000-1100 to the normal idle range), then it starts this "jumping", but not always. Sometimes it idles normally. Please help me if you can, and sorry for my bad english! Thanks!

You have a dousey here buddy.

I would first start with checking the IAC motor.

Also, with a jump idle as well, I am wondering if you possibly have a vaccum leak? You said you replaced the timing belt, are you sure you didnt split a vacuum line or forget to connect one back up?

Originally posted by eclipse982nrRST
You have a dousey here buddy. I would first start with checking the IAC motor. Also, with a jump idle as well, I am wondering if you possibly have a vaccum leak? You said you replaced the timing belt, are you sure you didnt split a vacuum line or forget to connect one back up?

Thanks man! I'll check the IAC motor and the vacuum hoses. I'm sure they are connected back, but some of them are rather old, it's possible that one could "break" like some kind of plastic. The PCV Valve hose did the same thing 2 months ago, so i had to replace it.

And what about the timing advance? Vacuum leaks can cause something like that, or i possibly have a faulty sensor? What do you think?

As Mike said check for vacumm leaks and then double and triple check.
Whats your vacumm reading in the intake manifold?
Check the EGR and make sure its functional, it can give you a massive leak.
You say it started happening when you changed the timing belt?
Check the timing and then a few more times.

Originally posted by rstare
As Mike said check for vacumm leaks and then double and triple check. Whats your vacumm reading in the intake manifold? Check the EGR and make sure its functional, it can give you a massive leak. You say it started happening when you changed the timing belt? Check the timing and then a few more times.

I'll check the vacuum hoses as soon as I have some time. I don't know exactly the vacuum reading. Digimoto displays the manifold pressure, but I didn't wrote down the values. Next time I'll check that too.

The EGR system is ok now, I'm sure. 2 years ago, when I bought the car, it had a trouble code, and the CEL was always on. The OBDII reader displayed only one code: P0401 "EGR Insufficient flow detected". The problem was a clogged EGR system, and a broken EGR vacuum hose. I cleaned the valve and the EGR tubes, and the vacuum hose was replaced. Then the CEL was gone, and it didn't come back anymore, so the EGR system is now ok. I checked the timing marks, they are aligned correctly, and this whole problem was started before I changed the timing belt, not after that.