1983 SC CIS Pressure Test Evaluation
 

Hello folks,

After a nearly 4 year engine and fuel system rebuild, I just conducted my first set of CIS fuel pressure tests. Using our favorite CIS reference thread and various other resources, I was able to obtain the following data:

1. Year of engine: 1983
2. US or RoW (Rest of World): US
3. WUR model number: 090
4. Ambient temperature at time of test (in degrees C): 32.7 deg C
5. WUR Resistance (in Ohms): 25.6 ohms
6. System Pressure (in bars): 4.75 bar
7. Cold Control Pressure (in bars): 2.1 bar
8. Warm Control Pressure (in bars): 3.4 bar
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): 2:20
10. Residual Pressure @ 5 min (in bars): 1.9 bar
11. Residual Pressure @ 15 min (in bars): 1.7 bar
12. Residual Pressure @ 30 min (in bars): 1.7 bar
13. Residual Pressure @ 60 min (in bars): 1.6 bar

Everything seems to check out per the Bentley except for the cold control pressure per this chart. It seems I need to be in the 2.8-3.2 bar range:

http://forums.pelicanparts.com/uploa...1564277023.jpg

What do you guys think? Is the Bentley accurate? My FD and WUR are freshly rebuilt by Mr. Tony Donato. Well rebuilt about a year ago with zero miles on them.

Thank you in advance.

Probably OK. Test the cold control pressure again when it gets colder ambient. 32C is already half warned up/ Did you have any problems starting the engine? Or, was the 2:20 time period from cold to warm using only the electrical heater in the WUR?

2:20 was the period from cold to warm using only the electrical heating in the WUR.

It is nice and toasty at the moment, so tough to test "cold". May repeat a couple more days to see what happens.

As far as starting goes, everything in this current engine setup is brand new or rebuilt, and I have not started it yet. Im trying to set my fuel and spark for engine break-in next week.

Prior to the engine and WUR rebuilds I never had any issues cold starting either.

You should be OK on the fuel side to start it up. Low cold control pressure will richen it up a bit, which should be just fine for start up. Is your -090 WUR adjustable, or just a regular WUR? Tony is pretty good with CIS stuff, so that should be the last of your worries. Good luck when you start it up.

Regular 090. Good to know its ok for the start up. Thanks for the feedback Pat!

I’d wait until cooler weather and check it again.

Your system pressure is in spec (4.5-5.2 bar) at 4.75 bar. I’ve found with today’s fuel that adjusting to the upward side of spec allows for much better starting/running. Adding a shim to the PRV and also replacing its o-ring(s) might be something to think about.

Start up.......
 

Jose,

Are you having problem starting the engine? I set the CCP particularly for this WUR below the chart value. That was intentional. I am away from home right now but still able to communicate via email. Keep us posted.

Tony

Will do Tony. I am starting it up next Saturday 8/3 so Ill report back.

2jmotorsports,
Is your engine (including rest of the CIS system) factory spec otherwise ?

The CIS is 1983 spec. The engine is factory spec except for some 964 cams and 1mm larger intake valves.