190E (W201) 1982-1993: 190E 2.3, 190E 2.6, 190E 2.3-16, 190E 2.5-16, 190 D 2.2, 190 D 2.5, 190 D 2.5 TURBO, 190E 2.5-16 Evolution I, 190E 2.5-16 Evolution II

2.5 16v stalling

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Feb 18, 2022 | 10:05 PM
  #51  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
You're welcome rufrob. 3rd shot was the worst form me too. It took me 3 days to get back to normal. Yet better than being incubated in a hospital....

Let me know how things measure with the AFM potentiometer after you are back to normal.

When you are done with all the AFM pot issue, we need to address your economy gauge as well. On a manual transmission that gauge needs to be pegged all the way to the left at anything over 700rpm with AC turned off and no heavy load on the Alternator (like aux fans running). If you have a working calibrated gauge that is 17inch-mercury of vacuum. I calibrated mine. Mine is pegged, and has always been accept in one occasion that I fixed. Let us not deal with that now, as we have bigger fish to fry and again, let's fix one problem at a time.

- Cheers!
Reply
Old Feb 21, 2022 | 04:20 PM
  #52  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Heart was willing but body was weak.

1 meeting yesterday was like a gremlin hit by water. Tuned into 4 meetings. Thankfully much got sorted out. 12-7 I couldn't eat. I was done by the time I got home. Had a beer and zoned out. I should get to it this evening time permitting.
Reply
Old Feb 27, 2022 | 12:18 AM
  #53  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
I've been crazy busy with work and project which has been on hold for parts. I've been dealing with rust bolts and fasteners, hard to access places, seized hydraulics and water pump. And of course hard to find replacement parts.
Attached Thumbnails 2.5 16v stalling-photo162.jpg   2.5 16v stalling-photo785.jpg   2.5 16v stalling-photo316.jpg   2.5 16v stalling-photo322.jpg   2.5 16v stalling-photo247.jpg  

2.5 16v stalling-photo771.jpg   2.5 16v stalling-photo705.jpg   2.5 16v stalling-photo553.jpg   2.5 16v stalling-photo910.jpg   2.5 16v stalling-photo630.jpg  

Reply
Old Feb 27, 2022 | 12:36 AM
  #54  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
I'll get back to the 16v when the F3 race car is running.
The pedal box and front hydraulics are done next find or rebuilt the water pump. I already have the timing belt and tensioner.
Then the fuel system and properly clutch.
Reply
Old Feb 28, 2022 | 12:19 PM
  #55  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Impressive. Are you repairing for someone or are you racing the F-3?
Reply
Old Feb 28, 2022 | 05:34 PM
  #56  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Repairing it for someone.
Told you here they give me the jobs no one else wants.
Reply
Old Mar 5, 2022 | 08:51 PM
  #57  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
I pulled the AFM and I noticed strange marks on it. I looked used since it's dirtier than surrounding components.
And one of the arms which touch the AFM was bent.
I got the following measurements

Ignition on
6-2=12.08
3-2=3.67
Cold idle
6-2=13.76
3-2= 8.28
Then it stalled an wouldn't restart.
It started doing the same thing. The sensor plate would go down at start then pop up and the engine stalls. If I adjust the throttle too tight to keep it open it would idle but it wouldn't rev and would stall.
Attached Thumbnails 2.5 16v stalling-photo500.jpg  
Reply
Old Mar 5, 2022 | 10:44 PM
  #58  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
I wish you had just followed the instructions in post #49 first before removing it. Now that you have put it back together. Can you take those measurements and report them?
#49. With the bent contactors of the AFM plate lever replacing the AFM pot would be futile.

Mercedes only sells the entire AFM assembly (with the AFM pot on it) for good reason. It assures the contactors are not in bad shape.
Unfortunately that assembly costs $500. AFM pot is $200.

But Before jumping to conclusions first take the measurements asked in #49 so we know what is going on from a far.

- Cheers!
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

New Mercedes-AMG SUVs Arrive With NEW V8 Engine: 12 Things You Need to Know

 Verdad Gallardo
story-1

8 Oddball Mercedes Ideas That Actually Made it to Production

 Verdad Gallardo
story-2

Dubai Tuner Gives the Mercedes G-Class An Entirely New Look

 Verdad Gallardo
story-3

Six Gift Ideas Your AMG Loving Dad or Grad Will Cherish

 
story-4

7 Craziest Things AMG Gas Ever Built

 Verdad Gallardo
story-5

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-6

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-7

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-8

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-9

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
Old Mar 6, 2022 | 02:09 AM
  #59  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Yeah sorry I muffed that. I blame terrible hay fever, meds, and inpatients
Reply
Old Mar 7, 2022 | 01:16 PM
  #60  
190Efan's Avatar
MBWorld Fanatic!
5 Year Member
 
Joined: Feb 2020
Posts: 2,002
Likes: 398
1991 190E 2.3
Originally Posted by rufrob
Yeah sorry I muffed that. I blame terrible hay fever, meds, and inpatients
As a fellow allergy sufferer, I'm totally sympathetic on that issue. It also sounds to me like previous owners of your car have used lots of questionable, mystery, aftermarket parts and that could also be part of the problem. This is why my engineer father always taught me to use OEM parts only. OEM parts were specifically designed to work with your car and they are more durable and they last longer, saving you money in the long run. I think my money is still on the EHA as your problem given my recent hard starting experience with my own W201. However, it's really important to go through a step by step check list to test every possible scenario in order to find the true culprit part. Dolucassi has provided a really good road map for doing just that so I would urge you to follow that road map and then let us know what your findings are. That will give us the best chance to help you diagnose the problem.
Reply
Old Mar 7, 2022 | 07:21 PM
  #61  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Thanks for the message.
The battery ran down from cranking. I charged it and will go through the checklist again.
Reply
Old Mar 11, 2022 | 01:41 PM
  #62  
190Efan's Avatar
MBWorld Fanatic!
5 Year Member
 
Joined: Feb 2020
Posts: 2,002
Likes: 398
1991 190E 2.3
Originally Posted by rufrob
Thanks for the message.
The battery ran down from cranking. I charged it and will go through the checklist again.
This is pretty obvious but make sure you don't burn out your starter with all of the cranking.
Reply
Old Mar 13, 2022 | 07:19 AM
  #63  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Finally got to check the resistance between 1-2 for the AFM Pot. 1-3.56 at WOT
Resistance moves gradually.
Attached Thumbnails 2.5 16v stalling-photo503.jpg   2.5 16v stalling-photo984.jpg  
Reply
Old Mar 13, 2022 | 07:44 AM
  #64  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
IGN off
6-2=12.3
3-2=0
IGN on
6-2=12.2
3-2=3.7
I have to keep my finger on the sensor plate to get it to idle
Attached Thumbnails 2.5 16v stalling-photo380.jpg   2.5 16v stalling-photo20.jpg   2.5 16v stalling-photo960.jpg  
Reply
Old Mar 13, 2022 | 01:07 PM
  #65  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by rufrob
Finally got to check the resistance between 1-2 for the AFM Pot. 1-3.56 at WOT
Resistance moves gradually.
Thank you. The 3.56 value is a little lower than spec at WOT but that is not your problem.

(1) And are there any discontinuities in the readings as you sweep?
(2) Please also measure resistance from pin 3 to pin 1 on the AFM pot. And during the sweep that should not change at all.
Reply
Old Mar 13, 2022 | 01:10 PM
  #66  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by rufrob
Finally got to check the resistance between 1-2 for the AFM Pot. 1-3.56 at WOT
Resistance moves gradually.
Thank you. The 3.56 value is a little lower than spec at WOT but that is not your problem.

(1) And are there any discontinuities in the readings as you sweep?
(2) Please also measure resistance from pin 3 to pin 1 on the AFM pot. And during the sweep that should not change at all.
Reply
Old Mar 15, 2022 | 12:58 AM
  #67  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
1-3=1.84. No change when sweeping
Attached Thumbnails 2.5 16v stalling-photo777.jpg  
Reply
Old Mar 15, 2022 | 01:22 AM
  #68  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Warmed up engine running
3-2=8.20v
6-2=13.69v
Hard to rev past 2000rpm as it backfires
Reply
Old Mar 15, 2022 | 01:41 AM
  #69  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
I richened it up and now it rev freely. Next wait and check the cold start.
Reply
Old Mar 15, 2022 | 12:09 PM
  #70  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by rufrob
1-3=1.84. No change when sweeping
All your values are less then half of mine. Does not seem right
You are measuring these with AFM pot unplugged right?
Are something is wrong with your meter.
I was expecting an open or a short but that is not the case.
It is possible there is something wrong with your wiring to the ECU or the ECU itself
Reply
Old Mar 15, 2022 | 12:12 PM
  #71  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by rufrob
Warmed up engine running
3-2=8.20v
6-2=13.69v
Hard to rev past 2000rpm as it backfires
ECU is still telling you the AFM pot is not working and it will not adjust fuel mixture properly in this state
Reply
Old Mar 15, 2022 | 12:18 PM
  #72  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by rufrob
I richened it up and now it rev freely. Next wait and check the cold start.
Futile. If your ECU is not working good luck adjusting that screw.
You need to first diagnose and fix the AFM pot issue.
Unplug the ECU and repeat those measurements (between pins 1-2-3 of the AFM pot) on the ECU side to vindicate the wiring.
Make sure your meter is not uncalibrated somehow as well by measuring a known resistance (in the car our elsewhere)

Like I said previously your resistances are half of what they should be. Never heard of that before unless something went wrong with your measurements or the meter is busted.
Reply
Old Mar 16, 2022 | 07:52 AM
  #73  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
Sorry I made a mistake. I took the afm pot reading from the harness toward the firewall not at the meter itself
At the afm pot 1-3=1839 some change when swiping but at wot the same.
1-2=1
Gradual increase while swiping then 0 from halfway
Reply
Old Mar 16, 2022 | 12:04 PM
  #74  
dolucasi's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Your results suggest you are taking the measurements with the harness plugged in. Unplug it, and re-take the measurements carefully and recording results in detail.
1-3=1839 ohms is not the right value.
Gradual increase for 1-2 is also not correct as it should go form ~1.5K ohm to almost 10.0K ohms during the sweep.

Unless you can converge on what is going on with the AFM pot you will not get very far in fixing your issues.
Reply
Old Mar 17, 2022 | 03:25 AM
  #75  
rufrob's Avatar
Thread Starter
Member
 
Joined: Feb 2013
Posts: 202
Likes: 13
From: Tokyo
W210 E55T
1-3=1.45
Wot=4.40
1-2=1.84
I realize for some reason 2&3 outputs on the afm pot were swapped.
Terminal x
2-6=12.28v
2-3=3.72

Idle
2-6=13.72
2-3=2.83
Reply


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 09:18 PM.

story-0
New Mercedes-AMG SUVs Arrive With NEW V8 Engine: 12 Things You Need to Know

Slideshow: Mercedes-AMG's updated GLE 63 S and GLS 63 bring a new-generation V8, subtle design revisions, and familiar supercar-rivaling performance figures.

By Verdad Gallardo | 2026-06-17 12:52:51


VIEW MORE
story-1
8 Oddball Mercedes Ideas That Actually Made it to Production

Slideshow: Mercedes has never been afraid to experiment, and some of its strangest ideas turned out to be surprisingly successful.

By Verdad Gallardo | 2026-06-10 17:43:40


VIEW MORE
story-2
Dubai Tuner Gives the Mercedes G-Class An Entirely New Look

Sideshow: A Middle Eastern tuner has transformed the Mercedes-AMG G 63 into an open-top special, replacing nearly every exterior panel in the process.

By Verdad Gallardo | 2026-06-10 15:29:50


VIEW MORE
story-3
Six Gift Ideas Your AMG Loving Dad or Grad Will Cherish

Slideshow: Six gift ideas your AMG loving dad or grad will cherish.

By | 2026-06-03 17:26:18


VIEW MORE
story-4
7 Craziest Things AMG Gas Ever Built

Slideshow: Sometimes AMG builds fast sedans. Other times, it builds twin-turbo V12 land missiles and six-wheeled off-road monsters.

By Verdad Gallardo | 2026-05-26 17:59:58


VIEW MORE
story-5
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-6
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-7
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-8
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-9
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE