Porsche 911sc cold won't start

[Gm2917]

Hello everyone, i got an 911sc 1981 in very good shape.

One day the car cold wont start, it starts for 2 seconds and shut down and it won't start the only way to make it start it's if a put some gasoline in the aire filter and it starts really good and i can drive it with any problems, i have 55psi of fuel pressure my wur its working right.

Can anyone help me please i have been really struggling with that problem that i can't reach whats is it making it.

Greetings

[boyt911sc]

Originally Posted by Gm2917

Hello everyone, i got an 911sc 1981 in very good shape.

One day the car cold wont start, it starts for 2 seconds and shut down and it won't start the only way to make it start it's if a put some gasoline in the aire filter and it starts really good and i can drive it with any problems, i have 55psi of fuel pressure my wur its working right.

Can anyone help me please i have been really struggling with that problem that i can't reach whats is it making it.

Greetings

Gm,

Could you clarify how you put gasoline in the air filter and get the engine to start? And what is 55 psi? Cold control fuel pressure? Thanks.

Tony

[996AE]

Sound like a trolling post

first post newbie and lingo is off...

[gomezoneill]

Keep pouring gas in the air filter housing and you're going to have a real problem.

[Funracer]

Have you been messing with the mixture? Or anything else recently?

[Gm2917]

Originally Posted by boyt911sc

Gm,

Could you clarify how you put gasoline in the air filter and get the engine to start? And what is 55 psi? Cold control fuel pressure? Thanks.

Tony

Hello tony, i spill some gasoline on the air filter so it could start

[Gm2917]

Originally Posted by Funracer

Have you been messing with the mixture? Or anything else recently?

The only thing we have done to it it's full service, spark plugs, filters, we changed the fuel pump check and service to the inyectors

[boyt911sc]

Originally Posted by Gm2917

Hello tony, i spill some gasoline on the air filter so it could start

GM,

Where are you located? I have been tinkering CIS motors for a long time and have no idea how spilling gasoline on the air filter could make it start. I thought you had a carburetor but saw “WUR” in the original post and concluded you got a CIS indeed.

You still have not answered my question, was 55 psi. cold control pressure or warm control pressure? Thanks.

Tony

[Gm2917]

Originally Posted by boyt911sc

GM,

Where are you located? I have been tinkering CIS motors for a long time and have no idea how spilling gasoline on the air filter could make it start. I thought you had a carburetor but saw “WUR” in the original post and concluded you got a CIS indeed.

You still have not answered my question, was 55 psi. cold control pressure or warm control pressure? Thanks.

Tony

I'm from Mexico , warm control pressure, i search for threads in here and i saw the cis dummy and i copied this, but i don't have the cold control prrssure because i don't have the right gauges.

1. Year of engine: 1981
2. US or RoW (Rest of World): us
3. WUR model number: 090
4. Ambient temperature at time of test (in degrees C): 13
5. WUR Resistance (in Ohms): 26.5
6. System Pressure (in bars): 2.89
7. Cold Control Pressure (in bars): -
8. Warm Control Pressure (in bars):3.58
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): -
10. Residual Pressure @ 5 min (in bars): -
11. Residual Pressure @ 15 min (in bars): -
12. Residual Pressure @ 30 min (in bars): -
13. Residual Pressure @ 60 min (in bars): -

[SkiVT]

You may want to post a picture of your gauge. If it can measure system pressure and WCP, it should be able to measure CCP. CCP is simply the pressure before the wur warms from the electrical current. WCP is the pressure after the wur is warmed by electrical current and to some degree by the engine IF you start the engine to test (which I wouldnt). Are you starting the engine or using a jumper for terminals 30/87a

[Gm2917]

Originally Posted by SkiVT

You may want to post a picture of your gauge. If it can measure system pressure and WCP, it should be able to measure CCP. CCP is simply the pressure before the wur warms from the electrical current. WCP is the pressure after the wur is warmed by electrical current and to some degree by the engine IF you start the engine to test (which I wouldnt). Are you starting the engine or using a jumper for terminals 30/87a

Hello yeah i can do that let me look for it, it's because when i start the car at cold temperature the gauge reads 55psi the top, but i will look for a picture of my gauge, and I'm jumping the terminals

[boyt911sc]

Originally Posted by Gm2917

I'm from Mexico , warm control pressure, i search for threads in here and i saw the cis dummy and i copied this, but i don't have the cold control prrssure because i don't have the right gauges.

1. Year of engine: 1981
2. US or RoW (Rest of World): us
3. WUR model number: 090
4. Ambient temperature at time of test (in degrees C): 13
5. WUR Resistance (in Ohms): 26.5
6. System Pressure (in bars): 2.89
7. Cold Control Pressure (in bars): -
8. Warm Control Pressure (in bars):3.58
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): -
10. Residual Pressure @ 5 min (in bars): -
11. Residual Pressure @ 15 min (in bars): -
12. Residual Pressure @ 30 min (in bars): -
13. Residual Pressure @ 60 min (in bars): -

Gm,

The WCP could not be greater than the system pressure (SP). In case of flow restriction in the system, the control pressure could get as much as the system pressure but never greater. Secondly, you don’t have the correct pressure gauge. Were you running just the fuel pump with the motor off? Or with a running motor? Please keep us posted. Thanks.

Tony

[Gm2917]

Originally Posted by boyt911sc

Gm,

The WCP could not be greater than the system pressure (SP). In case of flow restriction in the system, the control pressure could get as much as the system pressure but never greater. Secondly, you don’t have the correct pressure gauge. Were you running just the fuel pump with the motor off? Or with a running motor? Please keep us posted. Thanks.

Tony

Hello Tony yes you are right, i forgot to change that number, SP engine off, WCP engine on. And yes i do need the gauges. What other info can i give you that can help??

[boyt911sc]

Originally Posted by Gm2917

Hello yeah i can do that let me look for it, it's because when i start the car at cold temperature the gauge reads 55psi the top, but i will look for a picture of my gauge, and I'm jumping the terminals.

Gm,

The cold control pressure is too high. This is the reason you are having trouble getting it to start and run. Inspect your WUR’s filter screen for flow restriction. This is a common culprit. Use the correct pressure gauge and check your fuel pressures.

I am curious how you got 55 psi. (cold control pressure) using the pressure gauge shown in the picture above. Could you share with us how you did it? A picture how you installed it would be much appreciated. Thanks.

Tony

[Gm2917]

Originally Posted by boyt911sc

Gm,

The cold control pressure is too high. This is the reason you are having trouble getting it to start and run. Inspect your WUR’s filter screen for flow restriction. This is a common culprit. Use the correct pressure gauge and check your fuel pressures.

I am curious how you got 55 psi. (cold control pressure) using the pressure gauge shown in the picture above. Could you share with us how you did it? A picture how you installed it would be much appreciated. Thanks.

Tony

Hello tony sorry for the delay in the response, we put in the line of de WUR to the FD the gauge with the adapter and a connections i bought.
How is the WUR Filter screen?? And i will add the photo how i put the gauge in a bit.

Greetings
George