1993 190E 2.6 Runs for 3 minutes upon starting, then dies. Limp mode maybe?
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1993 190e 2.6I
1993 190E 2.6 Runs for 3 minutes upon starting, then dies. Limp mode maybe?
Hey guys! I'm new to the forum here. I hope I can gain some valuable diagnostic advice and insight on this. I've searched far and wide for info regarding what I'm dealing with, only to find dead threads with no useful answers. I'd like to think I have a fairly okay understanding of the KE-Jetronic system and CIS.
This is all of the recent parts replacement and preventative maintenance that has been performed to up-keep for peace of mind and potentially solve this issue. Spark plugs, plug wires, distributor cap and rotor, fuel injectors, OVP relay, MAS module, Fuel distributor rebuild with ultrasonic cleaning of all engine fuel likes and FPR. Extracted and replaced all old fluids.
I bought the car in an attempt to revive it from sitting for for 4 years. She idled great ,even before I replaced anything, but the issue was there to begin with and I'm kind of stumped.
The car runs and idles for approximately 3 minutes before shutting off on a cold start. It starts without any issue afterwards, but the time is dramatically shortened to about 10 seconds. During driving, maximum rpm is limited to about 3000-3500 and throttle is only responsive for about 25-40% of application. Any more than that and it'll fall flat on its face and bog down. When external power source is applied to the fuel pumps (in an attempt to bypass whatever is commanding the pumps to shut off), I can drive for a longer period but the speedometer stops working and it eventually bogs down regardless of amount of throttle being applied. I want to say this is "Limp mode" but can't say for certain.
I'm grateful for any input you may have. Thank you in advance.
This is all of the recent parts replacement and preventative maintenance that has been performed to up-keep for peace of mind and potentially solve this issue. Spark plugs, plug wires, distributor cap and rotor, fuel injectors, OVP relay, MAS module, Fuel distributor rebuild with ultrasonic cleaning of all engine fuel likes and FPR. Extracted and replaced all old fluids.
I bought the car in an attempt to revive it from sitting for for 4 years. She idled great ,even before I replaced anything, but the issue was there to begin with and I'm kind of stumped.
The car runs and idles for approximately 3 minutes before shutting off on a cold start. It starts without any issue afterwards, but the time is dramatically shortened to about 10 seconds. During driving, maximum rpm is limited to about 3000-3500 and throttle is only responsive for about 25-40% of application. Any more than that and it'll fall flat on its face and bog down. When external power source is applied to the fuel pumps (in an attempt to bypass whatever is commanding the pumps to shut off), I can drive for a longer period but the speedometer stops working and it eventually bogs down regardless of amount of throttle being applied. I want to say this is "Limp mode" but can't say for certain.
I'm grateful for any input you may have. Thank you in advance.
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Joined: Mar 2016
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From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Quite the opposite, it appears you are not in limp mode at all, which is why whatever the culprit is causing you trouble after the car warms up and the ECU starts the closed loop emissions operation.
Before diving into a diagnosis I would first test out my claim above. Put is in limp mode intentionally.
Start the car and run it till it dies after 3 minutes. Unplug the ECU or OVP whichever is more convenient for you and re-start the car. How does it run now?
Depending on the results we can dive into a Diagnostics cycle later.
- Cheers!
Before diving into a diagnosis I would first test out my claim above. Put is in limp mode intentionally.
Start the car and run it till it dies after 3 minutes. Unplug the ECU or OVP whichever is more convenient for you and re-start the car. How does it run now?
Depending on the results we can dive into a Diagnostics cycle later.
- Cheers!
Thread Starter
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Joined: Oct 2022
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1993 190e 2.6I
Quite the opposite, it appears you are not in limp mode at all, which is why whatever the culprit is causing you trouble after the car warms up and the ECU starts the closed loop emissions operation.
Before diving into a diagnosis I would first test out my claim above. Put is in limp mode intentionally.
Start the car and run it till it dies after 3 minutes. Unplug the ECU or OVP whichever is more convenient for you and re-start the car. How does it run now?
Depending on the results we can dive into a Diagnostics cycle later.
- Cheers!
Before diving into a diagnosis I would first test out my claim above. Put is in limp mode intentionally.
Start the car and run it till it dies after 3 minutes. Unplug the ECU or OVP whichever is more convenient for you and re-start the car. How does it run now?
Depending on the results we can dive into a Diagnostics cycle later.
- Cheers!
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Your welcome, and if you decide to unplug the ECU make sure the ignition key is in your hand. You do not want the unplug/hot plug an ECU.
- Cheers!
- Cheers!
Thread Starter
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1993 190e 2.6I
I've let it run for 3 minutes and die on its own. Pulled the keys out of the ignition and disconnected the ECU. Started her back up and she ran a bit rougher but not very noticeable. The car dies in about 15 seconds. I repeated the same process with the OVP relay and got the same result but the ABS light came on since it wasn't energized.
Today, I came across a forum thread that had somewhat similar issues but not exact, and it points towards the FPR. But before any accusations, let's break this down from what we have so far.
Today, I came across a forum thread that had somewhat similar issues but not exact, and it points towards the FPR. But before any accusations, let's break this down from what we have so far.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
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From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Ok, so your car is also failing to run in limp mode. So it seems you have 2 issues going on (at least). Unfortunately no low hanging fruit here.
The fact that it runs ok in the first 3 minutes suggests that in open loop mode it is fine.
When you removed to OVP and/or the ECU and it ran for 15 seconds or so, what was the rpm like. It should idle at high rpm like 1200, does it?
For it to be an FPR issue, it would have to start to not regulate after some time.
Who did your FD rebuild/cleaning?
It seems measuring your fuel pressures at this point is not a bad idea, since the car sat for 4 years. That is murder on this system. Things start deteriorating after 6 months, perhaps sooner.
Do you have the equipment needed to take the system and chamber pressures?
Good thing is the car runs for 3 minutes. That's all you need to measure the fuel pressures and also observe if something goes wrong after 3 minutes.
The fact that it runs ok in the first 3 minutes suggests that in open loop mode it is fine.
When you removed to OVP and/or the ECU and it ran for 15 seconds or so, what was the rpm like. It should idle at high rpm like 1200, does it?
For it to be an FPR issue, it would have to start to not regulate after some time.
Who did your FD rebuild/cleaning?
It seems measuring your fuel pressures at this point is not a bad idea, since the car sat for 4 years. That is murder on this system. Things start deteriorating after 6 months, perhaps sooner.
Do you have the equipment needed to take the system and chamber pressures?
Good thing is the car runs for 3 minutes. That's all you need to measure the fuel pressures and also observe if something goes wrong after 3 minutes.
Last edited by dolucasi; Jun 26, 2023 at 03:25 AM.
Thread Starter
Newbie
Joined: Oct 2022
Posts: 5
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1993 190e 2.6I
Ok, so your car is also failing to run in limp mode. So it seems you have 2 issues going on (at least). Unfortunately no low hanging fruit here.
The fact that it runs ok in the first 3 minutes suggests that in open loop mode it is fine.
When you removed to OVP and/or the ECU and it ran for 15 seconds or so, what was the rpm like. It should idle at high rpm like 1200, does it?
For it to be an FPR issue, it would have to start to not regulate after some time.
Who did your FD rebuild/cleaning?
It seems measuring your fuel pressures at this point is not a bad idea, since the car sat for 4 years. That is murder on this system. Things start deteriorating after 6 months, perhaps sooner.
Do you have the equipment needed to take the system and chamber pressures?
Good thing is the car runs for 3 minutes. That's all you need to measure the fuel pressures and also observe if something goes wrong after 3 minutes.
The fact that it runs ok in the first 3 minutes suggests that in open loop mode it is fine.
When you removed to OVP and/or the ECU and it ran for 15 seconds or so, what was the rpm like. It should idle at high rpm like 1200, does it?
For it to be an FPR issue, it would have to start to not regulate after some time.
Who did your FD rebuild/cleaning?
It seems measuring your fuel pressures at this point is not a bad idea, since the car sat for 4 years. That is murder on this system. Things start deteriorating after 6 months, perhaps sooner.
Do you have the equipment needed to take the system and chamber pressures?
Good thing is the car runs for 3 minutes. That's all you need to measure the fuel pressures and also observe if something goes wrong after 3 minutes.
I rebuilt the FD myself with detailed instructions from multiple sources. Differential pressure after EHA adjustment was 0.42 BAR. Flapper moves about 3mm before hitting the FD plunger with fuel pressure applied.
I feel confident that everything mechanical wise is nominal. Then again, I could've missed something.
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MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
How well does it run when cold?
Are there any diagnostic information / fault codes? At the X11 duty cycle port or the 16 pin OBD1 port?
Rebuilding an FD would not be something I ever considered when there are experts out there but kudos to you. Hopefully it went well.
I assume you tested it after you rebuilt? meaning you measured delivery from each port is equal, etc. etc.
Are there any diagnostic information / fault codes? At the X11 duty cycle port or the 16 pin OBD1 port?
Rebuilding an FD would not be something I ever considered when there are experts out there but kudos to you. Hopefully it went well.
I assume you tested it after you rebuilt? meaning you measured delivery from each port is equal, etc. etc.
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Thread Starter
Newbie
Joined: Oct 2022
Posts: 5
Likes: 0
1993 190e 2.6I
How well does it run when cold?
Are there any diagnostic information / fault codes? At the X11 duty cycle port or the 16 pin OBD1 port?
Rebuilding an FD would not be something I ever considered when there are experts out there but kudos to you. Hopefully it went well.
I assume you tested it after you rebuilt? meaning you measured delivery from each port is equal, etc. etc.
Are there any diagnostic information / fault codes? At the X11 duty cycle port or the 16 pin OBD1 port?
Rebuilding an FD would not be something I ever considered when there are experts out there but kudos to you. Hopefully it went well.
I assume you tested it after you rebuilt? meaning you measured delivery from each port is equal, etc. etc.
Yes, I got hardline and plugged all 6 ports with the lines running into test tubes. Using the hardwired button I have installed for the fuel pumps, I ran the pumps with the car off and pressed the flapper to induce fuel flow to the injection ports. All fuel ports deliver evenly.
I'll provide more updates once I get codes.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
You should also check the Duty cycle until it stalls. The ECU put's out a code in duty cycle as it is running as well.
Let us know when you have some numbers.
Let us know when you have some numbers.
MBWorld Fanatic!
Joined: Feb 2020
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1991 190E 2.3
I think Dolucassi has made some very good suggestions. In addition, here are some additional things that I'm wondering about. Have you checked your engine air filter? Have you checked to see that your fuel filter and fuel lines are all clear of debris? You might also want to check all of your engine electrical connections to make sure there's no dirt in them that could contribute to the problem. You might want to have a look at your new spark plugs to see if they've been fouled in any way. I'm also wondering if there might be some carbon build up in your engine that could be contributing to the problem. Have you taken your car on the highway and stomped on the accelerator multiple times to blow out any carbon build-up?
Junior Member
Joined: Nov 2009
Posts: 25
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1990 190E 3.0
For the car to run, you need three things: fuel, air, and spark. Since the car will run for 3 mins, every time, like clock work, we can rule out the spark and air, because neither of those will change once the engine is running. So issue is narrowed down to fuel. Several components control the fuel output and the amount of fuel: temperature, air flow potentiometer, throttle, etc. systematically check these systems to find out the cause.
