w124 94 e320 failed nj emissions please help
 

Hello all! long time no post for me as car was behaving :). Now car has failed state inspection for 2 parts of the emissions test and i kindly request your assistance. Standard for HC is 100 and car was emitting 121, standard for CO% is 0.50 and car was emitting 0.59. These figures are from the failed inspection printout performed at 2395 rpm. I have searched and read many posts for other similar situations with 94 and 95 e320's. Car does have a hard start when cold and over the past few weeks has required twice holding down the gas pedal a little to start. Car always cranks, but those 2 times would not idle and would shut off right when would release the key after trying to start it. Car does have a rough idle (when car has warmed up) and at times when trying to pass someone on the highway feels like drops a cylinder and i barely make it past the person. At that moment, it feels like i am running over train tracks (as car is violently shaking) and without letting go of gas pedal car eventually operates like normal providing good power to pass. I am not sure what the status of the wiring harness is, but the car does have 127000 miles and i purchased it with 111000 a little over 2 years ago. The check engine light is not on but I have done the led code reader numerous times. Got a total of 4 codes, but only decided to clear one. Pin 14 gives codes 2, 4, and 11. One time I got code 49 on pin 8 which i cleared and has not returned.

PIN 14 CC/ETA
code 2 - EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or Stop lamp switch or Cruise control switch or Actual value potentiometer or Starter lock-out/back-up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in EA/CC/ISC control module

starter lock-out has been bypassed by previous owner and the reverse lights do not always activate ever since the NSS was replaced which may be reasoning behind code 2

code 4 - Cruise control switch (S40)

cruise control works for me 9 times out of 10 and once deactivated itself when i hit a pothole

code 11 - Closed throttle recognition signal to engine control module (HFM-SFI or Left LH-SFI) Fuel safety shut-off to engine control module (HFM-SFI or left or right LH-SFI)

throttle cable/assembly has too much play which i have since greased up a little, but may soon take to mechanic for assistance. another member mentioned his throttle return spring was missing which may also be the issue here (don't remember if that car was a w124, but i could not find a return spring when i looked at my car)

and code 49 on pin 8 is Voltage supply at engine control module implausible/low volts

which i believe is tied to cars hesitation issue when trying to pass

I have already replaced the OVP which was before replacement and after replacement part number 5406745. I have a feeling hesitation issue began after i used the e320 to jump start another car causing me to suspect OVP was the issue

I know these issues can be as a result of many things, but I am leaning towards that the cars timing needs a slight adjustment, oxygen sensor needs replacing (even though not causing a fault code), or throttle actuator needs to be looked at. Car does not have ASR feature.

I am sorry for the long post and i thank you for taking time to read it

I would start with the easy stuff...
 

...as it sounds like an ignition-related issue:

How's your gas mileage...and have you pulled the plugs yet?

I'm thinking the plug wires are about due for replacement.

I'm only recalling the same situation last year when mine wouldn't pass, and I replaced plugs three times only to pull later and find them fouled. Eventually, the excessive fouling killed the O2 sensor.

Hesitation (and downright shuddering) when applying gas was another symptom.

Fresh plug wires made all the difference

I have noticed a little worse gas mileage than usual ... mechanic looked at all the plugs a few weeks ago, they were clean and he checked the gaps, he said they were fine. thanx g-benz for your help as i will look into replacing the plug wires. I was looking at prices online and they aren't bad at all

It sounds like the catalytic converter might be the problem. I've seen lots of cases where the vehicle will fail the smog test, barely. It's easy enough to test, but you'll need an emissions analyzer. What you need to do is "power brake" the car in "D" for a few seconds. This will heat the converter rapidly, and temporarily restore it's efficiency.

Has the engine wire harness been changed? My '95 started acting up everything I did just made it worse until I changed the harness. A bad cat won't cause the running problems you describe, although it can cause the car to fail emissions testing.

I appreciate the help guys .... in a few days I'm gonna bring the car to the mechanic and/or midas to check the cat ... as for the harness I am not sure if it is original, but i think i can get to its part number close to the OVP (that i saw on a sticker on the harness)

as an update so far only changed the 3 spark plug connectors (under the coils) myself and car's idle has improved a little or it may just be in my head. Car has not since hesitated like it did before. Only drove car a few times since but, the hesitation was randomly occurring anyway and time will tell if the connectors were the culprit. Next I am planning to change the plug wires and maybe even the spark plugs since I will be there anyway. In the process, I did notice oil in places that didn't amuse me though. On the #6 spark plug connector (closest to the firewall) and in all of the places I have circled in the attached picture. This pic is not from my car, but I found the pic online. The left two holes connect to the air intake and the other one is at the throttle actuator I believe, which all should be dry I thought. I know with my luck it won't be something simple like the valve cover gasket, but you guys have any ideas whats causing the oil to be there? or is this normal?

Took car to two different exhaust shops that only change exhausts and I figured out they do not have an emissions tester. One suggested I add a fuel injection cleaner to the car, but I don't trust those additives.

I would get a can of seafoam and run it into the engine through a thin vacuum hose, one that goes into the intake manifold. I use a clear plastic hose going from the fuel pressure regulator in the BMW so that I can see the stuff getting sucked out of the can. Let it sit for 15 minutes, then start the car and drive it on the highway. Be ready for the clouds of black smoke !

Once that is done, change the plugs and wires.


Also check the cold start injector and idle control valve. you might want to take the ICV off the engine and spray carb cleaner into it. Mine was stuck and cleaning it fixed it. When you take the car back to the inspection site, disconnect the cold start injector.

If your reverse lights don't work, you will fail the test.

I hated the inspections when I lived in NJ.

thanks there buddy as I will consider the seafoam .... I see it mentioned a lot on this site and even seen some videos of it in action on youtube ... I have confirmed that the throttle return spring is missing and I am going to the dealer to order one .... i guess tension for now makes the throttle return after i let go of the gas but there is too much play in the throttle cable .... a spring should make some difference in the idle before I investigate further

additionally, it seems the reverse lights were working during the test as the car passed the safety part of the inspection test and when i use the reverse i see the lights go on properly more often then not

<When you take the car back to the inspection site, disconnect the cold start injector.>

The car in question is HFM/SFI Full Electronic..there are no CSVs....