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  #31  
Old 04-25-2003, 11:00 AM
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Location: Colorado Springs
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engine off key on
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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  #32  
Old 04-25-2003, 11:03 AM
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no power
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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  #33  
Old 04-25-2003, 03:59 PM
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Join Date: Mar 2003
Posts: 64
Hi,

I had exactly the same symptons as you last weekend when I replaced my Air flow meter. The Zero position of the plate was not set on the new meter and therefore the idle period between that and the correct basic position was way off, and of course so was the duty cycle. I was seeing fixed readings at X11 pin 3 like you. So I adjusted the zero postion as outlined in the thread below. Zero being the plate at the top edge of the vertical cylinder in the air flow meter and basic being the lambda adjusted to the bottom of the vertical cylinder. When you depress the plate from zero position you can feel the resistance increase when the arm contacts the control plunger. The period between zero and the contact of the control plunger is the idle period. If there is no difference in resistance then it is likely the lambda is well out of adjustment and you need to set the basic position by lowering or leaning out the lambda until resistance is felt at the basic position, the bottom of the vertical cylinder. This at least will get everything set in the right position to begin tuning.

The idle period between zero and basic is max. 2mm. Set at 2mm my car wouldn't start, richened up a bit to about 1.5mm (ish!) I see 50% +/- 10%.

Setting new Airflow Meter - 190 16V

The old airflow meter I replaced also had the same problem, it's zero position was also incorrectly set. If zero is out you cannot set your lamda correctly. If you can't get the correct duty cycle within the idle period spec of 1-2mm you will have to investigate the control plunger seal clearance.

FWIW if the zero position is wildy out of spec (like mine) the idle can surge up and down like it's possesed. If you've also got hesitation under way, it could very well be a stuffed air flow meter potentiometer. Hey, I got lucky, I had the entire kit and kaboodle go west on mine. In the end it "only" cost me 300 because I was stubborn enough not to go to the dealer. I can really recommend reading the Bosch Fuel Injection & Engine Management by Charles O. Probst. ISBN 0-8376-0300-5

HTH
Neil
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  #34  
Old 04-25-2003, 05:47 PM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
ukevo

Thanks for the info, I thought I was doing something wrong, I am glad i am not the only one. I have everything hooked back up and my hesitaition is almost gone but still there only on acceleration from start. But no stall any more. I did nothing to change this so I have to now assume either the idle potentiometer or my Zero position is not in the right spot. Guess I have some playing around to do. Does anyone have the potentiometer settings for a 560 idle as I assume they may be different from the 190 16V.
thanks
m
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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  #35  
Old 04-25-2003, 06:04 PM
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Join Date: Mar 2003
Posts: 64
Hi Martin,

I'm not saying it's definitely the problem, just something to check - fingers crossed tho! Hesitation could be caused by many things such as fuel pressure, injectors, ignition etc.

I wouldn't worry about the pot readings specifically. Set your meter up to 20K ohmns scale and read pins 1-2 (from memory). I'm not sure on the 560 but you'll probably have a short harness that runs from the actual pot on the AFM to a main wiring harness connector located to the side of the fuel metering head/distributor. You can simply remove the connector plug and test the resistance values here, much more accessible than directly at the pot - well at least on my 16V the pot itself is virtually inaccessible under the intake manifold. So long as you have continuity in that short harness you'll be sweet. Don't need power to the unit to measure resistance.

Depressing the AFM plate, on mine I see 1K approx at zero position through idle period until I hit the control plunger then the values start to rise. If you can see a increase in resistance, no dropping out etc, no going infinity then at least the potentiometer is working to some degree. Finding the actual values might be very difficult, I couldn't even find them in the actual Bosch literature for my AFM, but I found a voltage chart instead. Be aware that the pot is not just for idle but also for running and if it's not working properly then you will get hesitation at cruise etc like I had. The worst thing about mine was the constant stalling, especially when turning, and the pyschotic idle 500-1500, 500-1500 ad infinitum!! LOL

HTH
Neil
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  #36  
Old 04-25-2003, 06:20 PM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
thanks. I am at a loss on my hesitation as it is new. Everything was fine then one day it starts doing it. Mine runs like a champ at speed so it is only on acceleration from a stop that you feel it once above 1000 rpms never felt it. I will do the ohm test tomorrow. It is incredibly easy to read on mine as the potentiometer so at least that is easy. I think I need to fix the X11 and EHA signal, If I can get mine to fluctuate again I will be very happy, and I think it will fix the problem.
Drving to Denver tonight to watch the Rockies Play the white Sox it is not cricket but it is still a load of fun.
I will update this weekend with where this is at.


m
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

Last edited by mhingram; 04-25-2003 at 06:54 PM.
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  #37  
Old 04-28-2003, 12:40 AM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
update

Okay, so either I am a moron or my new $25 harness (102-509-04-63-00) does not work. I used the harness on the eha, I got weird numbers. So I tried to use it on the idle control valve like Steve said, when connected my idle was about 1300 rpm the same as if it was not connected. SO steve you are right I am not getting a circuit. I have attached a picture of how I have this connected on the car. I am using my multimeter in mA setting.
My throttle switch is working great, Thanks for the plug break down Steve.

I also tested the idle potentiometer I am posting a picture and discussion seperately.
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

Last edited by mhingram; 04-28-2003 at 12:52 AM.
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  #38  
Old 04-28-2003, 12:48 AM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
part 2

On UKevo recomendaton I thought I would test the idle potentiometer. I pulled the plug and checked the ohms between plug 1 and 2. Very nice start at 1.5 then as depressed it increased very nicely, until suddenly it went from 3.98 to 42 then it went back down to 4.02 so I figure I have a bad conntact. I pulled the potentiometer after marking its position on the casing. I took a picture of it but it did not turn out as well as I would like, anyway the area highlighted is silver the rest of the arch is all a black colour, so I assume it is worn out.

thanks for any input.
m
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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  #39  
Old 04-28-2003, 06:35 AM
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Join Date: Jan 2002
Location: England
Posts: 1,841
Re: update

Quote:
Originally posted by mhingram
Okay, so either I am a moron or my new $25 harness (102-509-04-63-00) does not work. I used the harness on the eha, I got weird numbers. So I tried to use it on the idle control valve like Steve said, when connected my idle was about 1300 rpm the same as if it was not connected. SO steve you are right I am not getting a circuit. I have attached a picture of how I have this connected on the car. I am using my multimeter in mA setting.
Don't mean to insult you here, but everyone needs reminding of the simple things occasionally:

Secondary school physics - remember amps are read between 2 points, not across point like voltage

I'm sure you had it right anyway..! I've made that mistake before

Russ
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190E's:
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  #40  
Old 04-28-2003, 08:36 AM
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Join Date: Mar 2003
Posts: 64
Apparently you can try cleaning it with an eraser, but I'd just replace it myself. Also apparently, you can get a new pot without spring for the whole new airflow meter but it is difficult to calibrate it. That said I know a dutch guy who did it with no problem at all. I replaced the whole AFM - about 300.

As for the EHA current you need to put one probe into one socket and the other probe into the other socket. To test current through the multimeter. But I guess you are doing this already. You will notice the idle change when you do this as control back to the EHA or idle speed regulator resumes.. I find it utterly useless BTW to measure these sorts of things with a digital meter, thats why I have two - the analog one you can see trends with and they are cheap as chips so maybe get yourself one of these?

So anyway it sounds like the pot could be part of your problem, be sure to check duty cycle when you have it all back together as per Steve's article.

Cheers,
Neil
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  #41  
Old 04-28-2003, 01:30 PM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
Pentoman,
None taken, actually you got me thinking so I redid the test. Same results and you can tell it is getting something cause the idle changes between the connect and no connection, I also tested continuity and it is good. But my readings are all off, even checked with the old analog multimeter I have. The Part number for my Potentiometer is 3437224035 read it directly of the potentiometer I assume this is the bosch part number. Steve can you let us know when yours comes in if it is the replacement for this part. If it is could you order me one I would be happy to pay you a facilitation fee.
thanks
m

UKevo,
Thanks for the advice. I was testing all correctly. The idle potentiometer seems the guilty party.
thanks again for getting me to look here.
m
__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

Last edited by mhingram; 04-28-2003 at 01:37 PM.
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  #42  
Old 04-28-2003, 08:07 PM
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Join Date: Mar 2003
Posts: 64
Yes replace the pot or the AFM, but make sure to check the zero position and then the duty cycle. Fingers crossed!
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  #43  
Old 04-30-2003, 12:05 AM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
Potentiometer

Steve,
Any chance that the potentiometer you ordered came in. Is it as you expected?
thanks
m
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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  #44  
Old 04-30-2003, 09:32 AM
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Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Based on the way I ordered it, I only expect it this week. I ordered it in a way that didn't incur me any special charges other than shipping and I had it sent ground.

I'll double check that it is in process today.
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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
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  #45  
Old 05-17-2003, 01:20 AM
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Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
depressed

Well, I put the new potentiometer on the old girl this evening. Had no effect at all. I am bummed I thought I had found my problem. The eha still gives the same screwy readings as does the x11 with no flutuation at all. The only way to make the car work safely is to disconnect the eha, Idle is slightly rough but not bad and start takes about 5 secs. She then drives fine but my gas mileage is down to about 15 instead of 16. I have to find out why my circuit is screwed up and am open to any suggestions.
As a pointer with the eha connected the car stalls as soon as I accelerate warm or cold,once moving she is fine but I can not live with the stall.

What to check next for circuitry as I am convinced once that is fixed she will be happy again.

thanks
m
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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
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