YACT: Ruff idle on start...possible causes

[PricklyPete]

OK to start this off, I have a '99 Mazda Millenia S with close to 60K miles on it.

With that mileage, I know it will need some general maintenance (fuel filter, spark plugs, new timing belt, etc.). Just recently the car's engine runs a bit on the ruff side for a few seconds while in idle immediately after starting. As soon as I get the car moving, the ruffness goes away...and stays away even when the car goes back to idle. This behavior does not occur every time I start the car, but occasionally (1 out of 4 starts).

When I say ruffness, it seems like the engine is having difficulty staying in a running state. It's like it is hiccuping almost.

My question is, what is the probable cause? My guess is that the spark plugs need to be replaced...but I really have no clue and I didn't know it this was some signal that another component was about to fail.

One last note: This has been happening for about a month. It is happening more often than before though. The first time it happened was after the car had sat idle for about a week. When it finally got started, the problem above happened. The engine check light came on as well. I checked my owners manual and it said that 4 things could be causing the light to go on:
1. The car was out of gas (was not a problem...it was low, but not out).
2. The car's gas cap was off (also not true).
3. The "ROOM" fuse had blown. Apparently this fuse connects to the guages and clock. (the fuse was not blown).
4. A general electrical problem has occured (if this is not a catch all, I don't know what was).
Since the car was running fine after it got going, I ignored the engine check light and after a day, it went away. Well, it came back on about a week ago after a similarly ruff start, but went away about half a day later. Finally, on a 45 minute drive the other day, the light came on about half way through the drive and has stayed on ever since.

Any suggestions on what might be causing the ruffness and whether you think it is directly related to the engine check light, let me know. I am debating whether to try and do some of this work myself (save the timing belt...I really don't feel like tackling that).

Edit: Good god a lot of typos

 

There are just too many possible causes for me to tell you exactly what the cause is, but I can tell you to check for trouble codes first, then tune it up.

 

[PricklyPete]

Originally posted by: Roger
There are just too many possible causes for me to tell you exactly what the cause is, but I can tell you to check for trouble codes first, then tune it up.

How do I check for trouble codes? Sorry if this is a really ignorant question?

 

[CraigRT]

I wouldn't even worry about it.. cars have quirks.. if it runs fine, and no codes, it's likely fine

probably just something small anyways.

 

Your vehicle has OBD II, it is not possible without a scanner, as the general population in OT like going to Autozone to have thier codes checked, I suggest you go there too

 

[PricklyPete]

Originally posted by: Roger
Your vehicle has OBD II, it is not possible without a scanner, as the general population in OT like going to Autozone to have thier codes checked, I suggest you go there too

Thanks. I'll try to stop by on Saturday. How much does a service like that usually cost?

 

[PricklyPete]

Originally posted by: CraigRT
I wouldn't even worry about it.. cars have quirks.. if it runs fine, and no codes, it's likely fine

probably just something small anyways.

No...I know...I've had my share of cars with "quirks", but this one has been driving as smooth as silk up to this point. If I can get it back to running like silk...I'd like to do that. Of course I'd rather not be bum raped by the dealer at the same time.

 

Free

(as you can see, Ot'ers are cheap bastards)

 

[PricklyPete]

Great I'll definitely try to check that out this weekend then.

 

After they retrieve the codes (If there are any) get back to me and I will do my best to diagnose your troubles.

 

[StageLeft]

Originally posted by: PricklyPete

Originally posted by: Roger
Your vehicle has OBD II, it is not possible without a scanner, as the general population in OT like going to Autozone to have thier codes checked, I suggest you go there too

Thanks. I'll try to stop by on Saturday. How much does a service like that usually cost?

At a mechanic $30-60. At autozone...FREE! Just go to the counter and say you need your codes checked. The guy will bring out a scanner and hook it up under your dash and scan them for you

 

[PricklyPete]

Originally posted by: Roger
After they retrieve the codes (If there are any) get back to me and I will do my best to diagnose your troubles.

Thanks, I appreciate it. I will try and do it ASAP.

 

[Scarpozzi]

My Jeep had this problem. It idled rough and almost stalled a couple of times for the first few mins of it running. Believe it or not, it turned out to be the battery.

If you have another vehicle and some jumper cables, you could jump your car off and see if it still gives you those problems. The issue with my Jeep was that the voltage of the battery was enough to start the vehicle, but voltage dropped so much after the engine turned over that it couldn't power all of the ignition systems fully until the alternator charged the battery back up. It didn't make a lot of sense to me because I would have guessed the alternator would provide enough power as soon as it started to turn over.... I guess it just doesn't push the same current as the battery.

Other than the battery, check your spark plugs for carbon build up and see if you can clean the car's throttle assembly. It could always have something to do with the fuel/air intake. Before I replaced my battery, I got some carbrator-type cleaner. (even though my jeep is fuel injected) and I scrubbed the whole assembly with an old toothbrush. That'll clear up a lot of small issues of carbon deposits and gunk and make sure everything is running clean.

 

[PricklyPete]

Originally posted by: Scarpozzi
My Jeep had this problem. It idled rough and almost stalled a couple of times for the first few mins of it running. Believe it or not, it turned out to be the battery.

If you have another vehicle and some jumper cables, you could jump your car off and see if it still gives you those problems. The issue with my Jeep was that the voltage of the battery was enough to start the vehicle, but voltage dropped so much after the engine turned over that it couldn't power all of the ignition systems fully until the alternator charged the battery back up. It didn't make a lot of sense to me because I would have guessed the alternator would provide enough power as soon as it started to turn over.... I guess it just doesn't push the same current as the battery.

Other than the battery, check your spark plugs for carbon build up and see if you can clean the car's throttle assembly. It could always have something to do with the fuel/air intake. Before I replaced my battery, I got some carbrator-type cleaner. (even though my jeep is fuel injected) and I scrubbed the whole assembly with an old toothbrush. That'll clear up a lot of small issues of carbon deposits and gunk and make sure everything is running clean.

I apppreciate the advice...I'll take that into consideration after I get the codes checked.

 

[dabuddha]

Originally posted by: Skoorb

Originally posted by: PricklyPete

Originally posted by: Roger
Your vehicle has OBD II, it is not possible without a scanner, as the general population in OT like going to Autozone to have thier codes checked, I suggest you go there too

Thanks. I'll try to stop by on Saturday. How much does a service like that usually cost?

At a mechanic $30-60. At autozone...FREE! Just go to the counter and say you need your codes checked. The guy will bring out a scanner and hook it up under your dash and scan them for you

Tried it twice but both times I was told my car was too old to hook up (94 Accord) My check engine light has been coming on for the last 30000 miles or so. My friend's dad told me if it's an American car, you're fscked, if it's a Japanese car, you're safe

 

[Soybomb]

My friend's dad told me if it's an American car, you're fscked, if it's a Japanese car, you're safe

So your dads friend knows nothing about cars is the point?

 

[Ornery]

"With that mileage, I know it will need some general maintenance (fuel filter, spark plugs, new timing belt, etc.)."

"I am debating whether to try and do some of this work myself (save the timing belt...I really don't feel like tackling that)."


Why not slap your plugs and wires in there? There's probably a whole bunch of service due at this point. Check the owner's manual and take care of everything due at this point. Get all the fluids changed and filters for sure. I doubt any of these things are the problem, though. Since that check engine light came on right at the same time the trouble kicked in, it likely is electrical related. I'm curious what that computer is actually able to monitor. Would it sense that a plug or wire was no good or arcing? If the fuel injector was clogged? Well anyway, wouldn't hurt to perform the scheduled maintenance yourself.

 

[StageLeft]

Originally posted by: Ornery
"With that mileage, I know it will need some general maintenance (fuel filter, spark plugs, new timing belt, etc.)."

"I am debating whether to try and do some of this work myself (save the timing belt...I really don't feel like tackling that)."


Why not slap your plugs and wires in there? There's probably a whole bunch of service due at this point. Check the owner's manual and take care of everything due at this point. Get all the fluids changed and filters for sure. I doubt any of these things are the problem, though. Since that check engine light came on right at the same time the trouble kicked in, it likely is electrical related. I'm curious what that computer is actually able to monitor. Would it sense that a plug or wire was no good or arcing? If the fuel injector was clogged? Well anyway, wouldn't hurt to perform the scheduled maintenance yourself.

The computer can pick up a whole whack of things - I think it can do misfiring spark plugs for instance.

dabuddhaIt's possible that they don't have the equipment for your car. For my 00 maxima the first autozone I brought it to could not pull a code (the light was on; I knew there was a code). The baffoon there thought maybe my computer was bad. I brought it to another autoznoe and they had a better scanner, and pulled the codes fine. In fact I think the first one the guy was doing the wrong thing (OBDI vs. II for instance).

 

[PricklyPete]

Originally posted by: Ornery


Why not slap your plugs and wires in there? There's probably a whole bunch of service due at this point. Check the owner's manual and take care of everything due at this point. Get all the fluids changed and filters for sure. I doubt any of these things are the problem, though. Since that check engine light came on right at the same time the trouble kicked in, it likely is electrical related. I'm curious what that computer is actually able to monitor. Would it sense that a plug or wire was no good or arcing? If the fuel injector was clogged? Well anyway, wouldn't hurt to perform the scheduled maintenance yourself.

I may just do some of this myself, but I have to admit, this is not a fun car to work on at all. As much as I appreciate the extra power I get with the SuperCharger, it is a mess just trying to get to the spark plugs. What should take 30 minutes to an hour looks like it could easily take 4-5 hours. The intercooler is completely blocking the front row of spark plugs and the back row is nearly invisible behind a number of items...none too easy to take out. I may still end up trying to do it myself, but it definitely is going to be a hassle.

I totally agree though that there is a lot of maintenance that needs to be done anyway, so I should do most of that and see if I'm still having a problem.

My plan of attack is:
1. Get my engine codes checked at AutoZone. Depending on what the results of this are, I may have a better idea of what needs to be done.
2. Check to see if battery needs to be replaced.
3. Do scheduled maintenance like spark plugs, filters, belts.

Hopefully 2 and 3 will be all that is needed, but step 1 might indicate a larger problem that I will have to take care of. Thanks for all the input guys.