CIS pressure test results ?

[johntom]

Hi
I have just done the pressure tests on my UK 1980 3.0 SC with the following results (wur part number ends in 069):
System pressure 4.7 bar, 68 psi
Control pressure cold 2.2 bar, 32 psi
Warm pressure 3.2 bar, 46 psi

Are these results good or bad ?

[ossiblue]

Those all look good, however the cold control pressure is dependent on ambient temperature, so that one may be out of spec. You will need to post the outside temperature (basically, the temperature of a cold engine) at the time you tested the cold pressure.

Also, you should test the residual pressure by leaving the pressure gauge attached to the system after recording control pressure and then shutting down the fuel pump. The pressure should drop below 2 bar fairly quickly but hold pressure above ~1.5 bar for more than 30 minutes.

[johntom]

Hi
The outside temp was around 19deg C, the engine hadn't run in 24 hours. I didn't test the residual pressure as the accumulator and check valve have recently been replaced which cured the hot start problem I had, should I still have done it ?
What effect would the cold control pressure being out of cause ?

[T77911S]

if it is hi, you will get the popping and backfiring due to lean mixture, low, it will surge, but your cold starts may be better.

[Bob Kontak]

The factory manual for the O2 sensor equipped 81 shows a range of 2.0 to 2.4 bar cold at 20C. It is the last chronological pressure graph in the catalogs I have. Assume that means the same through 83.

The ROW and USA parts catalogs show the same WUR numbers post 1980. However, there are two identical numbers shown in both catalogs for the 81-83 range. Perhaps one is a high altitude WUR?