Hello,

I have a 1993 300E with a 2.8L gas auto and 180k miles. My main issue with the car is throttle response when the engine is cold. Until the engine is fully warmed up, when driving the engine slowly accelerates without regard to how far down I push the accelerator. Once the engine is hot, throttle response is fine.

A couple strange issues are when the engine is cold, the throttle response is poor until I hit 2800 RPM. Once the engine hits 2800 RPM, the engine finally "takes off" and accelerates dramatically. I'm thinking the issue may be a vacuum leak issue but I have yet to find any visible leaks or cracked hoses.

Also, I have some hard starting in cold weather. If the engine does not start on the first crank without any throttle, then I have pump the throttle to get the engine to start. I don't think I should have to use throttle when starting a fuel injected vehicle.

I have a code reader with the blinking light from Ebay (works great), but after I reset the faults and fixed some issues, I'm showing no current faults for several weeks. I have also replaced the spark plugs, plug wires, air filter, water temp sensor, and air intake temp sensor.

I've done a lot of research on these boards and in books but before I pay to have a tech to go hunting for the problem, I would appreciate any possible suggestions you might have.

Thanks,

John B

Weird. Sounds like you might have an issue with the cold start injector. Anyone know how this works?

Typical of some M103 engines.
You may want to have your mechanic adjust the fuel distributor lower chamber pressure to .45 bar ( 6.5psi ) instead of .4 bar ( 5.8 psi )
This will compensate for the years of operational wear.
You'll need a CIS-E fuel pressure gauge to make the adjustment.

__________________
http://i19.photobucket.com/albums/b1...c/GOWIDE-1.jpg
1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES

<

The car is HFM/SFI w/104 DIS engine.
Check codes on pin 8 of Diagnostic Module and post.

__________________
A Dalton

Arthur and Ed,

Thanks for the replies. I ran the diagnostic on Pin 8 and it came back with one blink, no faults found. Any ideas on where I should check next?

Thanks,

John B

14

__________________
A Dalton

Arthur,

Thanks for the response. I checked pin 14 and I had one new fault I have not seen before: Fault 11.

My fault book reads "Pin 14 Fault 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 LH-SFI)."

I cleared the fault without a problem. Any idea what this means?

Thanks,

John B

Missed the year...you are correct !

__________________
http://i19.photobucket.com/albums/b1...c/GOWIDE-1.jpg
1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES

Arthur,

I will remove the OVP and check to see if it has been updated. I will post here tomorrow what I find.

JimY,

Not sure if the wiring harness has been replaced. It hasn't been replaced since I've owned in the last year. It looks as though the temp sensor is working though.

It has been suggested that I might have a bad O2 sensor or a vacuum leak. Would either of these cause the sluggish performance?

Thanks for the replies,

John B

Arthur,

I removed the OVP and checked the part number. The car has the new OVP 000-540-67-45. I also re-checked my diagnostics after driving the car for two days and both pin 8 and 14 had no faults. Please let me know if you can think of anything else to check.

Thanks again for the relies,

John B