94 e320 with ASR - Pin 14 Code 3 on rebuilt Actuator
 

I replaced Actuator twice based on computer diagnostics by MB dealer and inde. Rather than immediately accuse the re-builder, I blame myself and keep checking and testing to find something else that's causing the problem. I've listed what I think is relevant. Hopefully, you can suggest something I've missed that I can fix, so I don't have to send Actuator back to the re-builder.

Symptoms
Rough idle, engine shake @ 800 rpm with slight put-put at exhaust. Low power.
Low volume high pitch frequency "eeee" and irregular ticking from Actuator.
>> No other codes from the "Dalton Scanner"
>> No Check Engine, ASR or SRS Warning lights
>> Starts easily (couple of starter whirls)

Status
1] Accelerator Control Linkage * Moves freely with 3/8" slack in cable
2] Connecting rod (Actuator to Linkage) still at original setting
3] No fuel in vacuum hose to Fuel Pressure Regulator

Replaced [most recent first]
1] Purge Valve WD-40 treatment into MOT
2] Micro switch in gas pedal
3] Actuator
4] Vacuum lines / hoses > From Electric Crossover Valve to EGR, from Intake manifold "Y" to Fuel Pressure Regulator & Electric Crossover Valve
5] Spark plugs f8dc4 and connectors to coils
6] Hose 8" Intake manifold to head
7] Rebuilt EA Control Module & Actuator installed
8] Battery "B" Wiring Harness [DIY wiring]
9] Stop Light Sensor
10] Water Temp Sensor
11] EGR valve and cleaned EGR inlet into intake manifold and pipe
12] Engine harness (by previous owner)

Thanks to everyone for all your past assistance.
Bob
PS I have the Repair Manual on CD and sub to epcOnline Parts Catalog

What is the BATTERY/charging system voltage when the problem is happening?


Does the problem happen with the accelerator linkage disconnected from the throttle actuator?

Thanks for the reply Doc

Battery voltage [same readings from posts & connectors]
Ignition Off = 12v
Ignition On = 12v
Ignition Run = 15v [broke my digital, had to use old analog, that produced same readings on another car]

Accelerator linkage
Disconnected connecting turnbuckle at linkage
Ignition On = no change
Ignition Run = no change

Just a wag . . . but can you replace the EA/CC/ISC with a known good unit?? I see that you are using a "rebuilt" EA. Normally you get a "ISC faulty" when the ETA is bad/going bad???

How about the "OVP" . . . if your car has one?

If there's an over-charging condition the OVP will do it's job and start cutting the power supply to various control modules. Try dis-connecting the alternator temporarily and see if the problem goes away.

Wish I could get my hands on a "known good actuator and control module (EA/CC/ISC0) to confirm test. Inde's computer diagnosis indicated control module is ok.

Preious owner must have replaced OVP because it has newer part number.

Going out now to get new digital meter. And will disconnect alternator when testing.

Thanks
Bob

Tested with new Speery digital meter $20 @ Home Depot
Lots of people shopping for lots of stuff, but I controlled myself - made a list for Santa :D

New meter readings
Benz
Ignition off = 12.40v
Ignition run = 14.50v

Scorpio [to verify meter]
Ignition off = 12.60v
Ignition run = 14.15v

Time to retire the analog tester.

The reason that I asked about the voltage IS that that system is sensitive to excessive voltage...suggest disconnecting the alternator & see if the problem continues.

Hi Doc

Battery voltage with Alternator disconnected
Ignition Run = 11.79v

I've NEVER seen a bad EA/CC/ISC module! Have seen that it's been called out on the scanner as one of the options but in the final analysis, never seen one bad.

Swap: since you are working with an 'inde', maybe he will notify you when a similiar MB comes for service. That's the best way. If that verifies a good EA, then I'd bet it's the ETA.

If you used one of the providers on my page (Menu#24), I believe they would be happy to exchange it for you.

On closer inspection of the Actuator on your web site (Menu#24) the butterfly appears to be at a 90 deg angle to the barrel.
Before installing mine is definitely not at 90 deg (flat). Is it supposed to be?
It appears to be about 88 deg.
There is no change in the angle with and without the linkage and spring attached.

Also

Using gas pedal, engine will increase RPM until about 4100 rpm then it will feel as if missing severely and will not rev higher.

Any thoughts are appreciated.

Bob

<<<engine will increase RPM until about 4100 rpm then it will feel as if missing severely and will not rev higher.
>>

Rev limiter for torque converter when gear selector demand is N/P

I only tested in neutral.

I don't understand your comment
"Rev limiter for torque converter when gear selector demand is N/P"

Please expain.

That means unless there is a LOAD on the engine/drivetrain the engine is limited to that RPM.


Bob, does the code re-appear immediately OR does it come back after a period of driving?

Simply put, there is a torque converter safety limiter at 4K rpm if the car is in Park/Neutral..
Torque converters blow up at high rpms if there is no load on them..so the safety circuit design stops guys from reving the piss out of the car in N/P.