Slight miss at idle (only) - 99 Villager


JWH46
09-08-2008, 10:36 AM
Howdy,

I gave my Villager a tuneup (60Kmiles) with new plugs and wires, and I still have this slight stumble at idle. Runs great at all speeds, but just at idle there is a slight miss. Any ideas what to check next?

Airjer_
09-08-2008, 11:08 AM
Is the check engine light on?

JWH46
09-08-2008, 11:30 AM
No, no check engine light. Runs like a champ otherwise. All maintenance done according to schedule. I ran a tank of Lucas fuel injector cleaner through it (at double strength) so the injectors should be kind of clean. It's not a horrible miss, but enough to annoy me. I might take it to my local independent mechanic, and have him throw a code reader on it.

Airjer_
09-08-2008, 11:54 AM
If the check engine light is not on then there likely is no codes so scanning may not reveal any problems. This would also lead me to believe it is more of a mechanical failure rather than a "computer" or "component" failure.

These are notorious for bad fuel injectors but again if it failed it would have flagged a missfire code and turned on the check engine light. It may be possible that this is the start of something bigger and it may have to wait until it gets bigger to solve.

Unless the guy looking at it has some personal experience with this symptom in the past, it is likely you will have to live with it until it gets bad enough to start surrendering some clues to its origin!

It does seem like these tend to run ruff anyways so it may be a characteristic of the vehicle?

JWH46
09-08-2008, 12:33 PM
I think you may have a point. I'm kind of a fanatic about my cars, and their maintenance, but I'd hate to pay for the mechanic to tell me they can't find anything.

JWH46
09-13-2008, 11:33 AM
Well, swung by Autozone today, and had the codes read. It came up with PO325 - Knock Sensor. I thought I've read somewhere that something else (O2 sensors?) may cause this code to show up. No other codes were indicated, and the check engine light isn't on.

Any advice would be appreciated (before I take it to my mechanic).

tempfixit
09-13-2008, 09:09 PM
The knock sensors rarely fail on these vehicles, something else is setting the code. Wish I knew the answer for you, you state that you changed plugs and wires. What about the cap and rotor??? Make sure the distributor does not play on the distributor shaft.

Here is another forum site that has a wealth of info and good people that could possibly answer your question:

villagerquest@yahoogroups.com

JWH46
09-14-2008, 02:58 PM
Well, I slapped a new distributor cap and rotor on it...and no change. It's gotta be a fuel injector or something else beyond my shadetree skills. I'll report back what my mechanic finds.

JWH46
09-16-2008, 03:04 PM
Mechanic tried a new distributor, and that didn't make a difference. His meters showed it running really rich at idle, so it's new injector time. I'm going to have to save up for this one. Wow. Cheapest injectors I see are $115, times 6 plus labor is big bucks.

Airjer_
09-16-2008, 11:38 PM
JW I'm not doubting your "mechanic" but I think I would get a second opinion before replacing all six injectors. Injector failures do occur on these but typically the injector will go dead and cause an obvious misfire, severe loss of power, and a check engine light.

There are many possibilities that can cause the O2's to go rich. Bad O2, Dirty MAF, pressure regulator, low compression, week spark, vacuum leak and EGR valve are some other possibilities. Just hate to see that kind of money spent with no results to show for it.

JWH46
09-17-2008, 08:25 AM
I know, I thought about that, but his point was that you might as well do them all, rather than have to tear it down again when another one goes bad. It's running a ton better simply with the NGK plugs in there instead of the Motorcrafts, and with a fuel injector cleaning. I'm going to wait off on the injectors since it's running so much better. I think the only other thing I should do is clean the MAF, but I bet it isn't very dirty, with only 58K miles on it.

Thanks for the tips.

Airjer_
09-17-2008, 09:29 AM
You would be surprised what can sneak past an air filter! There is a screen in front of the MAF that catches the bigger stuff. We get them quite often in late spring almost completely covered in cottonwood!

Dennis Steele
09-17-2008, 06:52 PM
We are having nearly the same problems on the same vehicle.
I tuned it up....plugs, wires, cap, rotor etc.

Misses at idle and sometimes dies.
We took it to a mechanic and they replace the mass air flow sensor, o2 and something else.

It ran ok but with a slight miss. After 2 days it was back to stalling at idle.

A freind scoped it and told me it was the knock sensor.

Well I picked one up but I can't figure out where to put it!
After reading the advice here I am not so sure that this will solve it but I might as well put it in since I have it.

Where does it go?


PS.
Hi Airjer! :-)

JWH46
09-19-2008, 04:01 PM
We are having nearly the same problems on the same vehicle.
I tuned it up....plugs, wires, cap, rotor etc.

Misses at idle and sometimes dies.
We took it to a mechanic and they replace the mass air flow sensor, o2 and something else.

It ran ok but with a slight miss. After 2 days it was back to stalling at idle.

A freind scoped it and told me it was the knock sensor.

Well I picked one up but I can't figure out where to put it!
After reading the advice here I am not so sure that this will solve it but I might as well put it in since I have it.

Where does it go?


PS.
Hi Airjer! :-)

Dude, take it back... I've heard it's very common on these engines to get the knock sensor code. All that means is the knock sensor was activated by something else, so that's probably not it. Have the codes run on your van, and see if anything else shows up.

On mine, there were no other codes, so just as you did, I gave it a full tuneup. I just cleaned the MAF yesterday, and that didn't fix it either. My good local mechanic spent half a day working on it, and showed me on his fancy meters how the fuel pressure gets funky at idle and it runs rich. Then, when driving, all is fine. So, for me it definitely is the fuel injectors. However, with everything I've done, it runs so well, the stumble at idle isn't really that bad.

rhandwor
09-20-2008, 01:26 PM
Pull the vacuum hose on your pressure regulator if its leaking replace it as with high vacuum its pulling fuel into the intake. I seriously all your injectors are leaking.

drcoffee
10-12-2008, 09:53 PM
The PCV on these vehicles pulls a lot of oil into the intake. Spray some throttlebody cleaner on the butterfly valve and wipe it clean with a paper towl until the carbon is clear all the way around it. On mine it would get sticky and also hold open the plenum if build up is too thick. Then after that do a top end cleaning. Buy a can of Seafoam from any local parts store. run the engine until its warm and the pull the brake booster line off and with a high idle at 2000 rpm, start pouring the seafoam in the brake booster line. You don't want it to stall but you want to get it in as quick as possible. Don't poor too quick either. Then when you have just a little left let the idle back to slow and feed enough to stall the engine. Let it sit over night. In the morning start the engine and goose the gas to get it to smoke. Take it for a drive on a clear road and make some WOT runs. loading the engine helps to burn out the softened carbon deposit on the pistons and cyl head. It will take about 15 minutes of driving to burn out the carbon. This should help with any pre-ignition you may be getting causing the knocking. i just did mine and it made a huge difference in idle and acceleration.

Now as for the tune up. I did a tune up with new plugs, cap and rotor but not wires. It ran fine but 90k miles I thought new wiress were a good idea. I put new wires on and it ran fine. In a week it start to stumble at idle and in a few more days it ran like crap. Cyl 5 was misfiring and barely would let the van run. I had the codes read and knock sensor and #5 were the problem. I replaced the wire set again and the #5 plug and al was normal again. You may have bad parts if it all started after the tune up. If the bad idle was there before the tune up, consider a dirty engine with carbon build up on the pistons especially if you use the cheaper gas. Seafoam will help. If you want to see how to do seafoam, go to youtube.com and watch a few hundred videos. Every yahoo on the internet has posted one.

Come back and let us know what worked.

JWH46
10-14-2008, 08:59 AM
drcoffee,

Thanks for the tip. I'm a Seafoam nut myself, and haven't done the upper cleaning. I took off the Idle Control Valve and cleaned it - nope. Sooo..my last shot is hoping Seafoam works some magic. I'll report back what happens.

JWH46
10-20-2008, 09:13 AM
The PCV on these vehicles pulls a lot of oil into the intake. Spray some throttlebody cleaner on the butterfly valve and wipe it clean with a paper towl until the carbon is clear all the way around it. On mine it would get sticky and also hold open the plenum if build up is too thick. Then after that do a top end cleaning. Buy a can of Seafoam from any local parts store. run the engine until its warm and the pull the brake booster line off and with a high idle at 2000 rpm, start pouring the seafoam in the brake booster line. You don't want it to stall but you want to get it in as quick as possible. Don't poor too quick either. Then when you have just a little left let the idle back to slow and feed enough to stall the engine. Let it sit over night. In the morning start the engine and goose the gas to get it to smoke. Take it for a drive on a clear road and make some WOT runs. loading the engine helps to burn out the softened carbon deposit on the pistons and cyl head. It will take about 15 minutes of driving to burn out the carbon. This should help with any pre-ignition you may be getting causing the knocking. i just did mine and it made a huge difference in idle and acceleration.

Now as for the tune up. I did a tune up with new plugs, cap and rotor but not wires. It ran fine but 90k miles I thought new wiress were a good idea. I put new wires on and it ran fine. In a week it start to stumble at idle and in a few more days it ran like crap. Cyl 5 was misfiring and barely would let the van run. I had the codes read and knock sensor and #5 were the problem. I replaced the wire set again and the #5 plug and al was normal again. You may have bad parts if it all started after the tune up. If the bad idle was there before the tune up, consider a dirty engine with carbon build up on the pistons especially if you use the cheaper gas. Seafoam will help. If you want to see how to do seafoam, go to youtube.com and watch a few hundred videos. Every yahoo on the internet has posted one.

Come back and let us know what worked.

Okay, Seafoamed it on Friday night, before a short trip to Michigan over the weekend. It smoked out quite a bit, which was good. However, made no difference in the idle/stumble. I didn't have time to get to the throttle body. On the trip, got 22/23 mpg going 80mph with a full load, and it ran great...except when stopped at an idle.

I read somewhere about a fuel pressure regulator valve/module. Is that something to try next?

drcoffee
10-20-2008, 08:38 PM
Quick question, did you buy double platinum spark plugs?? The newer cars actually spark in both directions so a single platinum plug or small electrode tipped plug may only be getting spark one way or half the need spark. My daughters Civic ULEV had Bosch single plats installed when we bought it new. I could not find a cause for the rough acceleration and rough idle until I pulled the plugs and found the reason. New NGK correct plugs and she hums along now. Not all expensive plugs are alike.

drcoffee
10-20-2008, 08:45 PM
One more idea before you spend a bunch of $$ on the fix. Run some Techron fuel system cleaner in the gas and that may just clean your injectors for you. The Corvette crowd swears by Techron (Chevron product). Walmart or any auto parts store should sell it.

Airjer_
10-21-2008, 12:46 AM
Quick question, did you buy double platinum spark plugs?? The newer cars actually spark in both directions so a single platinum plug or small electrode tipped plug may only be getting spark one way or half the need spark. My daughters Civic ULEV had Bosch single plats installed when we bought it new. I could not find a cause for the rough acceleration and rough idle until I pulled the plugs and found the reason. New NGK correct plugs and she hums along now. Not all expensive plugs are alike.

Your problem was more likely the BOSCH plugs! Since you honda is either conventional ignition with a cap and rotor or coil over ignition the spark would only go one way.

JWH46
10-21-2008, 08:26 AM
Quick question, did you buy double platinum spark plugs?? The newer cars actually spark in both directions so a single platinum plug or small electrode tipped plug may only be getting spark one way or half the need spark. My daughters Civic ULEV had Bosch single plats installed when we bought it new. I could not find a cause for the rough acceleration and rough idle until I pulled the plugs and found the reason. New NGK correct plugs and she hums along now. Not all expensive plugs are alike.

Thanks for the idea, but been there already. I originally installed Motorcraft single plats, but my local mechanic swapped them out for the stock NGK's or whatever brand double plats. In addition, he tested every wire I replaced, etc. so there's no way it's a tuneup issue. Also, I ran triple strength Lucas fuel conditioner through the tank, in addition to the Seafoam. Runs like a champ...... at anything besides idle.

Airjer_
10-21-2008, 11:24 AM
I still think this is a mechanical issue that is a characteristic of the vehicle. If thats the case than there is nothing you can do to fix it short of replacing the motor and hoping for the best. Another thought is that it may be possible that the motor mounts are in really poor condition and instead of isolating the motor they are allowing the vibrations to transmit throughout the vehicle.

JWH46
10-21-2008, 11:43 AM
I still think this is a mechanical issue that is a characteristic of the vehicle. If thats the case than there is nothing you can do to fix it short of replacing the motor and hoping for the best. Another thought is that it may be possible that the motor mounts are in really poor condition and instead of isolating the motor they are allowing the vibrations to transmit throughout the vehicle.

Airjer,

Thanks for all of your advice. I think I might be a little too anal about the idle. There really IS a stumble there, but I know many drivers would barely notice it. I guess if I'm getting 23mpg on the highway, it's gotta be running right.

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