190e Code 11; Hesitation from Idle
 

Hi Folks,

The CEL light came on with Code 11 (air injection) and I discovered that one of the vacuum lines was disconnected. Checked for other vacuum leaks and no other leaks found. Reset Code and car started right up with no problem.

When I step on the gas, I can feel a slight hesitation from idle. When pass 1K the hesitation goes away. The hesitation is more pronounced as the car gets to full operating temperature from accelerating from 1K. At one point, the car died at idle when stopped. Car started and it felt like fuel deprivation at lower RPMs but okay at higher RPM when accelerating; managed to get home.

I will check the plugs, rotor, cap and ovp later after the car cools down. Is there a correlation with Code 11 and what I'm experiencing right now? I'm inquiring so I can be more efficient with my troubleshooting. Thanks in advance.

Well, Interesting enough Code 11 came back on the CEL codes. Is that a broken pump at this point? Any ideas?

unless the air pump is constantly pumping air into exhaust while running then it should not be an issue.

The weak point of the M103 is the ignition system.

- Clean the hard buildup in the cap with a hard tool (I have to do this every 2 months, also M103)
- check the resistance of your plug wires (1k just the wire, 2k from the cap to the plug)
- check what plugs you have in the engine and what they look like, clean

- If after all this you still have running problems then get a cheap $20 ignition coil off ebay and see if it helps because the insulation in them goes bad sometimes and it shorts out internally and it's hard to test stuff like that

I checked the cap, the wires, and the plugs are all in good condition. Using a code reader, I was able to determine that the MAS controller to pull the following codes:

Code 3 - TN/TD signal (RPM) interrupted
Code 5 - Output for air injection pump control defective
Code 13 - Excessive A/C compressor clutch slippage

Code 3 - i am not sure what this code refers to and it is probably attributed to the hesitation that I am currently experiencing when the car is at operating temp.

Code 5 - bad air/vacuum pump? Can anyone confirm for sure before i purchase a new one?

Code 13 - well, probably a bad compressor? I have no AC for a long time.

Code 3 - TN/TD signal is picked up by a rear crank sensor to the EZL and then the EZL sends it to the CIS ecu and the MAS relay. You can check for missing ignition signals with an oscilloscope. This stuff rarely fails.

Code 5 - maybe the clutch is disconnected/shorted out or a switchover valve for the checkvalve is disconnected/bad. I believe that the purpose of this exhaust air pump is to only run when the car is warming up. If it's turning when the car is warmed up it could create the problem you're experiencing

Code 13 - Clutch problem? These compressors have an rpm sensor in the back that's for emergencies when your compressor seizes up MAS relay will disconnect the clutch so that you don't throw your belt.

anyway the exhaust air pump, ac clutch are all controlled by the MAS relay. The fact that all these problems are kind of connected to the MAS relay could point to that relay.

Check your battery voltage when running

I still recommend replacing the ignition coil and checking the coil wire (No resistance for the coil wire).

Getting the CIS-E car with EGR and Air injection through the notorious CA smog every year must be a challenge. Glad I don't have emissions where I live. Good luck.

check out page 44 of this pdf:

https://www.startekinfo.com/StarTek/outside/11832/Resources/201Create/PDF/01002.pdf

Using this diagram you can check connections/Resistances

cleavster, when were the fuel filter and Oxygen sensor replaced last? Old ones could cause acceleration hesitation. You may want to inspect condition of the air filter also.

Here are the latest updates....

After more testing and rechecking, the code reader came up with another code on the MAS controller - Code 2.

Code 2 - Fuel pump relay (circuit 87) not functioning

If this code was true, I would not have been able to start the car and drive around without stalling completely. At this point, I was convinced that I may have a failing MAS Controller. Also, Christuna suggested that this may be a problem too on a previous post.

Changed the controller and codes 2,3,5, and 13 were gone. These codes were replaced by another code.

Code 11 - A/C compressor engagement signal missing (87Z)

Will this code engage the CEL light? I may have a real bad A/C compressor at this point? As I mentioned I did not have any A/C for a very long time. I have a leak somewhere.

Now, the car does not hesitate and no issues so far. I drove the car for an hour on the freeway and around town. However, The pesky air injection pump Code 11 is still appearing on the CEL.

Here are my observations:

(1) The CEL light comes on when the vacuum cycle through not the first time but on the consecutive vacuum checks. For instance, I'm idle on a traffic light and then you can hear the pump and the CEL comes on.
(2) There is no back pressure on the Fuel Tank when I added fuel today. Usually, I will hear a vacuum sound.

The only components that I have not checked are the following:

(1) Fuel Tank Purge/Regeneration valve (107-470-08-93-M22) - this valve is connected to the throttle body, charcoal canister, and to a solenoid switch.
What is the best way to check this? Can I just pull it out? Not sure how it is all connected inside the inner fender.

(2) Air Pump Check Valve (000-140-78-60-MBZ) - this valve is connected to the engine. It requires a large wrench size and I'm not sure what is the best way to remove and test the valve. The wrench I have will encompass the two threads so you will not be able to place one wrench to go one way and the other wrench the other way. Hope this makes sense.

Any ideas on this one?

BTW, battery voltage is at 14.3V when running.

There are ways to check it.

The fuel tank vent valve is supposed to hold 0.7 psi of pressure and up to 0.5 in-hg of vacuum (not much). Depending on the situation your fuel tank can be under pressure or under a very slight vacuum.

Sometimes what happens is the charcoal canister can get clogged and you will get weird issues like a gas station pump shutting off (happened on my car) or in an extreme case your fuel tank will collapse:

https://www.benzworld.org/threads/screwed-by-a-charcoal-canister.1712285/

This valve is usually located near the rear axle and from there it goes to the charcoal canister and from the canister to the throttle body and some models have a thermostatic vacuum switchover valve on the cylinder head.


To test it you can check for a vacuum leakage with a vacuum gauge to check for a torn diaphragm.

Of course check the vacuum line routing and an electrical connection to the switchover valve.


That's perfect