CIS problems - no cold control pressure
 

As the title suggests, I have no cold control pressure.

What could cause this?

For background, I have a car that won't start. I did start, ran fine, but recently and suddenly wouldn't idle below 2000rpm. Now it won't start at all.

I have a good spark but don't appear to have fuel.

The car has been sitting for a while so I replaced the fuel filter. I carried out the pressure tests and results are as follows:

Car is a ROW 1980 SC
System Pressure - 3.6 bar
Cold control pressure - nil.nada.zip.
Warm Control Pressure - 2.0 bar at around 3 minutes
residual pressure - 1.8 bar at 5 mins, 1.4 bar at 15 mins.
WUR - 0438 140 072 at 21 degrees C it gives 10.5 ohms

Everything I know about CIS I learnt here. I don't understand how the CCP can be 0. My best guess is the fuel accumulator...but I am guessing.

Any help greatly appreciated.

Ben.

Tony will chime in here but perhaps it's just the plunger or spring in the WUR that's connected to the metal diaphram has fallen out. That doesn't explain how you have warm pressure though.

Please tell me everything will be ok..

System pressure is low, perhaps check fuel pressure after the pump and after the filter/accumulator.

Everything about your WUR.......
 

Ben,

The fuel pressure readings from your WUR are all out of spec including the heater resistance. As you now experience, it will not start nor run. You need to find a good working WUR. If I were you, I will test the delivery pressure of the FP.

I could lend you a WUR-072 in case you want to see how your engine would run with a newly rebuilt and good working WUR. Test the WUR in your car and send it back to be after the tests. Or send the WUR to me for FREE test and evaluation. BTW, where are you located? PM me if your are interested.

Tony

Tony will sort you out. It's probably just a worn out WUR and or fuel pump. All quite easily fixed.

It will be ok if you listen to Tony.

Listen to the man. Do what he says. Dump every bit of info you have out here.

Many peeps sort of hide stuff. Be ok with feeling embarrassed, if that's what it's called. I am not accusing you of anything. Just report, report, report.

Sounds like the WUR is toast.

I am embracing the embarrassment. When first attempting to sort the non-starting car, I thought I had fuel, based mostly on the smell. Later realised it was the leaky Ducati parked a few feet away ... I am a fool.

Anyway, I want to thank this forum for all the people on it willing to listen to my amateur efforts, and kindly point me in the right direction. Its great to be able to make mistakes and not get trolled.

Tony, I'll gratefully accept your offer, I have pm'd you.

many thanks

ben

The people on here do it for the love of it and are exceedingly generous. I don't know where else I could find a place where peeps are willing to lend time and expensive tools to complete strangers for free.

This is the best thread for starting out trying to understand CIS. Great reading:

http://forums.pelicanparts.com/porsche-911-technical-forum/758788-cis-troubleshooting-dummies.html

G.

I filled my cylinders with gasoline on a nice beer drinking afternoon in Houston in the 90's lifting the sensor plate. I thought I was Batman because I read it in a book that you could engage the injectors with the key "on" by lifting the sensor plate.

And I did that for way too long.

Pistons cannot compress gasoline. Now who's the fool?

I once drove my car to work and noticed I was low on fuel. I ran an errand at lunch not thinking about the fuel. Half way home the car died. I coasted into a gas station. Troubleshot the ignition for a few minutes and ended up having it towed home. I eventually realized that I was out of fuel.

An official member of the fools club.