1980 350 Se W116 Fuel Pressures

[jpp]

I Have A Problem With The Fuel Pressures On My 350se 1980. If I Am Correct The Warm-up Regulator Regulates Start Up And Warm Running Pressures, In Other Words The Richness And Leanness Of The Mixtures.

Can Somone Please Tell Me What The Correct Presures Is For Cold Warming -up And Warm Running Must Be??

Can These Warm Up Regulators Be Repaired, And Why Does It Have An Electrical Element Inside? Does This Regulator Not Get Its Heat From The Engine?

When Does This Element Switch On, As Mine Is On The Whole Time, Hot Or Cold??

[ctaylor738]

You have the basics right. The warm-up compensator (WUC) controls enrichment by changing the control pressure in the fuel distributor, sending more or less fuel to the injectors. The lower the pressure, the richer the mix.

I don't have the specifics for your car, since it is not a US model, but in K-Jet systems, which I assume you have since your car is a 1980, you should see 1.2-1.6 bar at 20 degrees coolant temp. This should rise to 3.5-3.8 bar at operating temperature.

You should have a vacuum connection on your WUC as well. This allows enrichment on acceleration and load. Full load enrichment is 2.5-2.9 bar.

The warm-up pressure is controlled by resistance in a metallic strip connected to the electrical leads. About all you can do is to make sure that you have 12V going to the WUC, and make sure that you have some resistance - not an open circuit - across the electrical contacts in the WUC.

I have never heard of anyone repairing these.

If you send me an email, I will send you some stuff off the CD.

[jpp]

Thanx To Ctaylor I Know Checked The Control Pressures On My Car And Found The Following: On Cold Testing I.e. Coolant Tempreture At 22 Degrees Celsuis With The Motor Idling The Control Presure Was 2.02bar, The Warm Control Presure Was Still 2bar, However The System Presure Tested At 5.5bar.

Diconecting The Full Load Enrichment Vacuum Pipe At Idle Speed Made No Change In The 2.0bar Control Presure. However After Testing And Shutting Down Of The Engine The Presure Stayed Steady At 2.0bar For Hours.

I Got Hold Of A Warm Up Regulator Of A 380se W126 At The Breakers Yard With Bosch End Number 028 And Payed An Equivalent Of $35.00 For It. I Fitted Same And Tested With The Following Results:cold Control Presure At 22degrees Celsuis Was 1.1bar, Warm Control Presure Was 3.6bar, Full Load Enrichement Was 2.7bar, And The Break Away Time Was 4minutes, After That The Control Presure Rose To 3.6bar After 6 Min.

The Car Now Runs Like The Day I Pulled It Of The Showroom Floor 245000km Ago.

Thanx Ctaylor