y33 idle jerk / hesitation discussion (lets fix this!!)

[UM97Q4.1]

bean, I had the same mysterious dead battery thing about 3 months ago. Replaced the alternator and like you said everything was running great...............for about a week, then back to the same old crap.

I just got my car back on Friday (did not have it for a week,had some suspension work done) used it all weekend and it has not acted up once yet. I just cant figure this car out, it will run great for a few days then fall apart for 2.

Q45tech, I really appreciate all that you provide but seriously, no disrespect intended, you may as well be writing in Chinese. If I understood half the stuff you were talking about I would have had this fixed long ago.

[beancan]

The ecu via Consult or OBD2 data scanner shows the actual voltage provided to ecu in real time.

As to AC ripple riding on DC alternator, VOM contains an AC position that allows this ripple to be accurately measured. Sure it is an average ripple not a peak as observed via an oscilloscope, however this can be estimated accurately.

If 13.8 volts is produced then 1.38 volts ac superimposed ~-20db and 138 millivolts ~ -40db ripple

http://www.labscopes.com/pg09.htm

"Typical AC ripple on a healthy alternator/battery system is about 10-20 mV as read on a DVM. A single open diode can produce in the “Y” diode matrix, anywhere from 200 mV to 800 mV ripple depending on the age of the battery. A shorted diode will produce much higher ripple until the shorted diode is blown open by excessive current draw.

Also the age of your battery is a factor in Alternator whine. Alan had mentioned that your battery is a large capacitor and this is true. The frequency reactance of a battery to alternator whine changes with age. The battery impedance increases with age and your battery will become less of a filter as the years pile up. Buying a new batter will reduce the effects of alternator whine but that is masking the problem for a properly working alternator should produce very little AC output ripple. ........."

Understood, were on the same page. I know what to do now.

[beancan]

Q45tech, I really appreciate all that you provide but seriously, no disrespect intended, you may as well be writing in Chinese. If I understood half the stuff you were talking about I would have had this fixed long ago.

Q45tech is VERY smart, and if you ask him what time it is - he will tell you how to build a watch.. He reminds me of the "stig" from top gear.. Mysterious, unknown, but the best at what he does..

Everything you need to know about what were talking about can be easily learned and researched on google - take that extra step and expand your mind.

If we all keep brainstorming and working like this, there will be a solution.. thats what this place is for, and without brains like q45tech - it would be useless

Thanks to all of you, and I will keep you informed of my findings.

[Q45tech]

The difficulty is not with the mechanical aspects in any component of a vehical design but with the electronics and software which require a different mindset from the mechanic of yore.

An automotive technican attempts to bridge the two disciplines, however what is taught in even the best techical college is woefully inadquate for modern cars.

Years ago electronic techican had to deal with suddenly complex IC and microprocessors the results were not pretty for those that refused to go back to school and become engineers.

[beancan]

OK - Check this out.. what should be the normal voltage at the battery at idle with all accesories turned on?

AND - if the voltage was say... 12.5 at that point.. could it cause a missfire?

I think I found my problem!-Bean

[bdijanni]

Bean, I am so glad your all over this problem, because this is my girls car, and its so bad that we are thinking about getting ride of it, but I cant give up and either can you. So we have got to figure this out! I did the KS' and the top two o2 sensors not it! I was wondering about a couple of things? EVERY ONE THAT HAS CHANGED THEIR PLUGS AND EXPERIENCED THE PROBLEM, I need to know what kind of plug you are using. Every one that is having this problem what kind of plug are you using??? I need the exact plug model that you guys are using? Also does anyone that is running an after market Ignition system have this problem? PLease if you have anything other then a stock Ignition system please tell me, Will help with a lot of questions and theories that I have? Plus the lady is driving me crazy about fixing this! UM97Q4.1 have you notice the problem since you got your car back?

[bdijanni]

Oh yeah I have a stupid question. You guys were talking about changing out your alternator's! How did you get the Alt braket to stay on as you feed the hold down bolt through the alternator? You know Im talking about the bolt at the bottom of the alt the braket just falls off at the back of the alt I cant figure out how to get that thing to bolt back up?

OH YEAH, My car has been throwing codes!!! First it was the p0303 the KS' and also had the o2 code. Fixed those and nothing was still giving those codes for awhile. Just checked the codes last weekend and it gave me a p0300 code which is Mult cylinder miss fires? What does that mean? My car does feel like its miss firing? But goes away with the stumble??? Anyone know what this p0300 is? And what should I be looking into?

[UM97Q4.1]

UM97Q4.1 have you notice the problem since you got your car back?

yes, it is back just as bad as ever. Was hoping to replace MAF this past weekend but the suspension mod took a little more time and money than I thought.

[bdijanni]

What kind of plugs are you running??

[bullittandy]

Oh yeah I have a stupid question. You guys were talking about changing out your alternator's! How did you get the Alt braket to stay on as you feed the hold down bolt through the alternator? You know Im talking about the bolt at the bottom of the alt the braket just falls off at the back of the alt I cant figure out how to get that thing to bolt back up?

Tape it.

[emoq45]

When i shift it kind of feels jerky? could it be a transmission problem?

[bdijanni]

Guys, I need to know what kind of plugs you are running I have a theory about our problems!!! I need to know what kind of plugs all of you are running in your stumbling Q45?? I have the bosch platnum plus'

[UM97Q4.1]

just went to check the plugs and could not get the hood open , every time I let go of the latch I can hear it click back and lock. I am probably gonna have to get someone to help me get it open

[Q45tech]

Failure to utilize oem as specified plugs often causes SERIOUS PROBLEMS.

When we find non oem plugs as part of diagnosis we INSIST they be replaced even if 1 week old before we agree to proceed further.

[bdijanni]

So no one has answered the question. Bullittandy what kind of plugs are you running???

[beancan]

I'm sure, he is running the proper plugs.. You know, the ones that CAME in your car. OEM.. They are specified in the owners manual, the fsm (which I recommend you download from phatg20.net) and READ THEM ALL..

I will help, because... well just because..

You need to run ONLY the OEM plugs NGK PFR5G11 PERIOD..

Ive heard ok things denso PK20PR-11, but - I say NO.. only the NGK's

[bullittandy]

I'm runing the Iridium version of the stock plug, previous plugs were stock and had 30K miles on them.

I expereinced this problem a couple of times shortly after I bought my car but it was so slight that I didn't think about it. Its been away for 35K or so and I've done all the required maintainence except hot tanking the intake.

[dodiho]

BullittAndy...I think you might be on to something with my '99 q...The TCS/SLIP/ABS dash lights are all on and they came on at one time in a severe rain storm with my cruise control on..it now doesn't engage and the lights stay on....You told me to change the relay,but which one as there are 3 of them near the ABS pump on the firewall....or do you mean ALL three? I will order from the fellow in Arizona-?- forgot his name...Thanks,Doug(dodiho) in Texas

[bdijanni]

I'm sure, he is running the proper plugs.. You know, the ones that CAME in your car. OEM.. They are specified in the owners manual, the fsm (which I recommend you download from phatg20.net) and READ THEM ALL..

I will help, because... well just because..

You need to run ONLY the OEM plugs NGK PFR5G11 PERIOD..

Ive heard ok things denso PK20PR-11, but - I say NO.. only the NGK's

There is no reason to be rude or condescending about this man! I simply asked what everyone is running I realize that I need to change out my plugs, But wanted to see if anyone else was running non OEM would have made some scents if it was the plugs. Oh And I do have the FSM and I have read it, was AGAIN JUST ASKING A QUESTION. Trying to figure this mess out! I have been working on this longer than you Bean! SO you need to read up on older threads and realize that doing the KS' and O2's is not the problem here. And I've tried telling you this a couple of times.

[beancan]

There is no reason to be rude or condescending about this man! I simply asked what everyone is running I realize that I need to change out my plugs, But wanted to see if anyone else was running non OEM would have made some scents if it was the plugs. Oh And I do have the FSM and I have read it, was AGAIN JUST ASKING A QUESTION. Trying to figure this mess out! I have been working on this longer than you Bean! SO you need to read up on older threads and realize that doing the KS' and O2's is not the problem here. And I've tried telling you this a couple of times.

I was not being rude.. I was simply stating that the spark plugs are not going to be an issue (unless they are CRAPPY plugs) I had the rather expensive denso's in my car, changed to (ngk) with no difference.. Still missfired.. The reason for my answer is because people ask THE SAME questions and come across totally DUMB about the Q and its workings. If you go back, read ALOT, even on OTHER CARS Missfiring.. You can learn ALOT. We would be MUCH more advanced if EVERYONE read the @*&#&*@#(*&!@# FSM through and through.. You may have got something I missed.. ECT..

You may have been working on this longer, but I know I work harder.. Thats because im a physco and the problem is on my mind EVERY DAY.. I have gone through everything in my head 100 times an hour.. for 2 months now and tried everything.. Ohmed EVERY sensor, solenoid and connecter.. Cleaned them all, ran grounds everywhere.. I know its not the freakin o2's.. I know its not the KS's .. Its not the freakin coil packs either.. Thats why I haven't replaced ANYTHING on my car but the plugsWhats the only thing I didn't check??

I am 99.9% sure that I have found the cause of MY misfire.. I'm just waiting on my VERY expensive part to arrive so I can install it.. GUESS.. ?

Information to everyone else..

My car -- no MIL - no stored codes.. NOTHING.. Never had any either. Runs great.. Randomly skips at idle.. Thats it.. All the other BS it was doing went away when I changed the plugs.. (GO NGK GO!!) 17 mpg in the city!!! Which is good considering the traffic i sit in..

The story of how a broken part yells @ you to fix another..

My power antenna is broken, and when you turn the radio off - the motor runs.. For a while.. It goes VRRRRRRRRRRRRRRRRRRRR. Its consistant, and I notice it when I turn the car off.. well, I was at a light and it started jerkin, and It (%$*($%#@ me off.. So I turned the radio off.. Just to hear that DAMN antenna motor VRRRRRRRRR... Well, everytime the car skipped, the power antenna motor slowed for a split second then back to normal.. Everytime it jerked it would do it..

Keep in mind my cars RPM's dont drop but -+50 rpm when it skips...Sometimes not at all... just a "bump"

Now, playing with the antenna vrrrrrrriiinnggg... I turn on other accessories to hear the load.. BAD..

Out comes the voltmeter.. AGAIN.. this time from the cigarette lighter.. It wont missfire if im under the hood.. ever.. and wont do it when I have the voltmeter handy..

Now verified, by a broken part singing an un even tune when the car missfired..

the ALT is bad.. Confirmed officially "bad" by the machine at advance..

I mean, I knew it was weak.. but not that weak.. it made less than 30 ampsAnd trust me, the cables are REALLY good

[bullittandy]

This is an interesting idea-bad alternator. I've got 233K miles on my car and the orginal alternator was replaced by dealer (recall) at abour 100K so I must be getting close to the end of the second one. I'll be interested to hear what you discover.

[beancan]

I will let you and everyone know the results when it arrives

PS - car stops like a DREAM now. thx for the rotors!

[UM97Q4.1]

well, as I stated on page 1, I replaced my ALT 3 months ago and.........well read my post.

[beancan]

well, as I stated on page 1, I replaced my ALT 3 months ago and.........well read my post.

Its "known" bad so i'm not loosing anything.. My misfire may be different from everyone elses.. It has to be it. Ive done everything else!!!

The only other thing I can think of... It may sound crazy.. .But I don't remember the car doing it till I changed the oil...

I gave it castrol 5-30 ... Might be a bit thin for down here.. Silent as can be, but what if an HLA isnt pumped up as good as its supposed to be.. Or I have a sticky valve.. or a weak spring??

Jeez.. I wish my mind would rest...

[96Qowner]

What's the resolution on Consult software? Sampling rate, etc. Someone should hook up their laptop and drive around. If the sampling rate is high enough, something would show up, wouldn't it?

[bdijanni]

I was not being rude.. I was simply stating that the spark plugs are not going to be an issue (unless they are CRAPPY plugs) I had the rather expensive denso's in my car, changed to (ngk) with no difference.. Still missfired.. The reason for my answer is because people ask THE SAME questions and come across totally DUMB about the Q and its workings. If you go back, read ALOT, even on OTHER CARS Missfiring.. You can learn ALOT. We would be MUCH more advanced if EVERYONE read the @*&#&*@#(*&!@# FSM through and through.. You may have got something I missed.. ECT..

You may have been working on this longer, but I know I work harder.. Thats because im a physco and the problem is on my mind EVERY DAY.. I have gone through everything in my head 100 times an hour.. for 2 months now and tried everything.. Ohmed EVERY sensor, solenoid and connecter.. Cleaned them all, ran grounds everywhere.. I know its not the freakin o2's.. I know its not the KS's .. Its not the freakin coil packs either.. Thats why I haven't replaced ANYTHING on my car but the plugsWhats the only thing I didn't check??

I am 99.9% sure that I have found the cause of MY misfire.. I'm just waiting on my VERY expensive part to arrive so I can install it.. GUESS.. ?

Information to everyone else..

My car -- no MIL - no stored codes.. NOTHING.. Never had any either. Runs great.. Randomly skips at idle.. Thats it.. All the other BS it was doing went away when I changed the plugs.. (GO NGK GO!!) 17 mpg in the city!!! Which is good considering the traffic i sit in..

The story of how a broken part yells @ you to fix another..

My power antenna is broken, and when you turn the radio off - the motor runs.. For a while.. It goes VRRRRRRRRRRRRRRRRRRRR. Its consistant, and I notice it when I turn the car off.. well, I was at a light and it started jerkin, and It (%$*($%#@ me off.. So I turned the radio off.. Just to hear that DAMN antenna motor VRRRRRRRRR... Well, everytime the car skipped, the power antenna motor slowed for a split second then back to normal.. Everytime it jerked it would do it..

Keep in mind my cars RPM's dont drop but -+50 rpm when it skips...Sometimes not at all... just a "bump"

Now, playing with the antenna vrrrrrrriiinnggg... I turn on other accessories to hear the load.. BAD..

Out comes the voltmeter.. AGAIN.. this time from the cigarette lighter.. It wont missfire if im under the hood.. ever.. and wont do it when I have the voltmeter handy..

Now verified, by a broken part singing an un even tune when the car missfired..

the ALT is bad.. Confirmed officially "bad" by the machine at advance..

I mean, I knew it was weak.. but not that weak.. it made less than 30 ampsAnd trust me, the cables are REALLY good

Okay Man, no harm no foul... I am simply the same way I think like you are! I am constantly thinking and working on this problem its driving me crazy!!!! And I got to thinking about the plugs and couldnt remember if anyone said anything about them. So thats why I was asking. I've read so many threads and posts about this that every thing is starting to run together. And all the stupid questions and ideas are killing me! My car is doing the exact same thing accept I am getting a code for mult miss fires, and you said that by changing out your plugs for the NGK's everything else went away! Thats probably part of my problem. So your saying that you think it might be your Alt?? I should get mine checked out then? I did the volt meter test and seemed fine so I never thought about it again

[beancan]

Okay Man, no harm no foul... I am simply the same way I think like you are! I am constantly thinking and working on this problem its driving me crazy!!!! And I got to thinking about the plugs and couldnt remember if anyone said anything about them. So thats why I was asking. I've read so many threads and posts about this that every thing is starting to run together. And all the stupid questions and ideas are killing me! My car is doing the exact same thing accept I am getting a code for mult miss fires, and you said that by changing out your plugs for the NGK's everything else went away! Thats probably part of my problem. So your saying that you think it might be your Alt?? I should get mine checked out then? I did the volt meter test and seemed fine so I never thought about it again

My car has never iluminated any light on the dash, or had any codes. So I think my condition is ever so slightly different than everyone elses.. My alternator should be in soon, and I will let you all know of the results.. I recomend having the charging system tested any time you work on a fuel injected vehicle.. Low volts / amps can or AC ripple can cause all sorts of wierd things.. Its free, and they load test it well - some machines will even look for diode waveform oddities (advance auto parts machine did) Good place to start!!

With your multiple cyl missfire, it *could* a number of things.. I would definately check out your EGR system.. And Vac leaks. That seems to be the #1 cause of that.. Hell, could be the CAS too.. At least your car was kind enough to tell you something is wrong.. My car thinks its perfect.. It's concieted ...

[bdijanni]

Okay I replaced the plugs with the most expensive ones the NGK laser iridiums, now the car is only stumbling at an idle and sometimes during acceleration. Happens when you let off the gas for a second to coast then press the gas again. But thats it

[beancan]

Well.. The alternator seems to have solved it.. For today.. Ill keep you informed. Car runs MUCH better too

[bdijanni]

I had mine checked at advanced no problems at all with the bat or alt