Rough Idle after changing timing / drive belts
 

2003 DX. 140,000 miles. Just had Midas change the timing and two main drive belts [replaced the valve cover gasket too]. After driving away from the shop it began to lose rpms at idle [but hasn't died]. It also seems to have a lag / slightly jerky at acceleration. Once at cruising speed it's fine. I've only driven it less than 40 miles and will take it back to the shop on Tuesday but any clues what's going on? The hose that connects into the air box filter broke and was doing something similar but since rigging it with a tie-down cord has been running just fine until I had this work done. TIA.

They may have forgotten to re-connect a vacuum line. You may actually be able to find it yourself.

They have miss-timed/aligned the timing belt.

Thanks Tan & Grim. Well, I took it back today and they said needed to replace the ignition coil. Well after keeping it for 7 hours the car actually runs worse now then when I took it in this morning!

Other than the issue with the hose / air box my car has never exhibited these problems until they replaced the timing / drive belts! Taking it back in the morning.

The reaper is probably right. I had the same issue with my 92 when I got it. Did a basic tune up and fuel filter with no improvement. It ended up being the timing belt was off a tooth at the crank and it was running the valvetrain /timing too advanced. ran strong near redline though. I hope they don't charge you for that ignition coil.

Yes, they did charge me! Are you saying that when they changed the timing / drive belts it had something to do with the ignition coil going bad?

Moth:
I actually had the same issue with my '98.
The book shows how to align the intake camshaft sprocket with the exhaust cam shaft sprocket with two arrows or triangle pointing perfectly to each other like http://www.2carpros.com/forum/automo...9_mazda1_1.jpg

except in the real world they almost line up. And you have to decide if you pull the inlet back one tooth or forward 1 tooth. I don't recall which way I corrected it.(I think I set the intake cams clockwise by 1 tooth and the tensioner pulled it back to a close match)
I thought I messed up the coil because it misfired so bad and replaced the distributor that has the coil in it. That didn't help, so I checked the alignment of the marks and corrected them.
I can't completely blame them for getting this wrong (if it turns out to be that way) but they are professionals......

Mine is running great with the timing belt and new distributor. But I didn't have to pay labor!

Thanks tan! I'm printing that off and will give it to them. I'll ask them to fish my old coil out of the trash [since they never gave it to me] - maybe it's still good! The shop manager was out yesterday, I'll speak with him this morning.

They said the problem was a dead spark plug which killed the ignition coil. Car is running better now.

It's running MUCH better but still not the same as before I had the belts replaced. It's still running a touch slow on RPMs and ocassionally sputters at idle [does it more when the A/C is running]. What could be going on now that they haven't caught the 1st three times!

I think what the problem may be is that they take the car for a short test drive - it runs fine - and they assume it's fixed. I had to drive it for maybe 20 miles before it started acting up. Of course, now it you could probably witness the symptoms [with the A/C running] but going around the block a few times.