Fuel problems perhaps?

[coolngroovy]

74 2.7 CIS

Car runs for a few seconds & then dies.
I've held the lever in the airbox up until the injectors bleed, then it will fire straight up, but die.
It hasn't been running for quite a while. The fuel tank is clean, fresh fuel, new fuel pump, replaced the plugs & leads.
When it fires, i can hold it on 3000rpm for 2-3 seconds before it dies.
Am i running out of fuel?

[stlrj]

A cracked air box will act like that.

[coolngroovy]

Should i re-fit the airbox cover before starting?

If i press on the gas, the car stalls.

I'me going to spend the day trying to find the problem. Does anyone have suggestions as to what i should check?
This is my first Porsche & a huge learning curve for me.
Cheers, Col.

[boyt911sc]

Col,

Your cold stating problem could be caused by any of the following. Low fuel pressure, unmetered air (vacuum leak), bad WUR, stuck AAR, etc. The CIS components (fuel pump, warm-up regulator, auxiliary air regulator, etc.) could be tested individually without running the motor. Locating the vacuum leak is a little bit tricky for a non-running motor.

Even with a new fuel pump, it is good to know your system and control (cold) fuel pressures for baseline reference. After you have tested your CIS components and all confirmed working properly, a vacuum leak is mostly the culprit. Keep us posted.

Tony

[coolngroovy]

G'day Tony.
The banjo fitting arrived a couple of days ago. I fitted it yesterday.
I've had the front up in the air for a couple of weeks doing other stuff, so i figured the fuel pump would be getting supply.
When i turned the pump on, i could hear it priming, so i didn't worry about pre priming the fuel system.
I dont think i am having cold start issues. It fires straight up, but just wont accept any gas.
Today i will pull the fuel line after the filter, turn the pump on, & monitor the fuel supply over a few minutes. That should tell me if i have a constant supply?
I have noticed yesterday, if i fire it up, it will idle for around 10 seconds before stalling. If i give the accelerator a push to keep the revs up apon starting, it will only run for 2-3 seconds. That's why i'me thinking fuel supply problems.
The lever [red] on the handbrake doesn't seem to do anything. Perhaps a broken cable? Doesn't this lever activate a solinoid?
Also Tony, as you are familiar with the '74, another quick Q please,
I have a fuel hose coming from the right hand side bottom of the WUR. It is blocked off with a bolt.
Directly behind the WUR, there is a fuel block mounted on the bulkhead. It has 4 outlets. I have another fuel hose coming from there with a bolt in the end also. Both hoses are small diameter.
Would you know where these hoses are supposed to be connected?
Thanks mate. Cheers, Col.

[RoninLB]

Originally Posted by coolngroovy

If i give the accelerator a push to keep the revs up apon starting, it will only run for 2-3 seconds. That's why i'me thinking fuel supply problems.
.

my previous stock CIS always ran perfect so I don't have much troubleshooting experience. If you wind up chasing a vacuum leak later I'll jump back in.



this thread may assist with pump test
How do I troubleshoot the fuel pump?


also I changed the gas tank screen as preventive maintence. They sometimes clog after 100,000 miles. If pump test shows low gas flow maybe that's an option?

[boyt911sc]

COL,

What's the number on your WUR? Do you have 0-438-140-009? Please take pictures of the WUR and post it. You'll probably get more feedback with a close-up shot of the WUR and the bulkhead you mentioned. My reference shows '74 to have WUR (0-438-140-009) as shown below:

Tony

[coolngroovy]

Tony, that WUR is the same as mine. Although yours in marginally cleaner.

Pics will take me a little while. I'me on to it.

[coolngroovy]

Batteries just went flat in the camera. Just my luck!



Yah! Proud of myself for being able to post a pic without assistance from the kids!

Strangely embarressed about showing the world my dirty engine!

[boyt911sc]

Col,

From the CIS troubleshooting section (Bentley) table a:

Engine starts but fails to idle (this is your motor's status now):
Probable cause of fault:
1). Air-flow sensor plate rest position incorrect.
2). Fuel pressure incorrect.
3). Fuel injector clogged.
4). Auxiliary air regulator faulty.
5). Vacuum leaks.
6). Control plunger in the fuel distributor binding or FD faulty.
7). Idle speed, ignition timing, and idle mixture (CO%) out of adjustment.
8). Incorrect ignition timing or faulty ignition system.
9). Control pressure regulator faulty.

So these are the areas where you have to investigate to pin-point the culprit/s causing the motor not to idle properly. Since the motor has not run for a long time, the integrity of the the CIS component/s should be verified and checked. Good luck.

Tony

[coolngroovy]

Thanks Tony.
You can see the 2 hoses i refer to in the pic. Do you know where they should be connected to?

[boyt911sc]

COL,

I see the braided hose with a plug by the WUR. But I don't have any clue where the other other end is attached. Please take a close-up shot of the top view (WUR) maybe that will help us identify this hose. Which other hose is in question?

Do you have a CIS fuel pressure gauge kit? I've not seen any fuel pressure data in your posts.

Tony

[coolngroovy]

The hose with the blue arrows is going to the underside of the WUR.
The hose with the red arrows is going back to the bulkhead.

I dont yet have a fuel pressure gauge m8.

The weather has beaten me today. Time to down tools & pick up a beer.
Merry Christmas. Cheers, Col.

[coolngroovy]

The hoses look factory.
I'me not convinced about the bolts though!

[boyt911sc]

COL,

The braided vacuum hose (blue arrow) from the WUR is connected to a thermovalve if the motor has one. Secondly, the WUR is installed backward. The vaccuum port (blue arrow) should be pointing away from the engine. The braided hose with red arrows is difficult to determine with this picture alone. If you could show where the other end of the hose is connected, it would be easy.

I will make a guess at this point (w/o knowing whether this hose is a fuel line or vacuum line). Do you have a two-port or three-port fuel accumulator? If you have a two-port FA, this hose in question could be the return fuel line to the tank (???).

Lastly, the WUR (0-438-140-009) that is shown in the ealier post has no vacuum port at the side. Are you sure we got identical stamped number on the body? Another request, please post picture of the fuel filter and fuel accumulator in the engine bay. Thanks.

Tony

[coolngroovy]

Hope this helps m8.


This is where the hose goes to. Some type of metering block.



Top view of WUR.



Hey, i think i'me getting the hang of posting pics!

[boyt911sc]

Col,

In the first picture, is the black hose (next to the braided hose) going to the WUR? I believe picture #1( above) shows the fuel return lines from the fuel distributor, WUR, and unused hose (braided hose).

You still have not answered my question about your fuel accumulator. Do you have a 2-port or 3-port FA? Just show us the picture of the fuel accumulator and fuel filter combo. Thanks.

Tony

[coolngroovy]

Tony,
The black hose is going to the WUR,
The last pic m8 is the f.a? Or have i photographed the wrong thing?

Shouldn't you be drinking eggnog & roasting chestnuts m8?
I watch my US sitcoms.

[boyt911sc]

Col,

The last picture is the fuel filter/fuel accumulator. I looked at it and somehow miss to register in my mind. Looking at the last picture, the fuel accumulator looks like a two-port unit. If you had a three-port FA, the other braided hose with a plug should be attached to the bottom of the fuel accumulator.

So right now, those plugged lines are not needed for your engine set-up. Get or borrow a fuel pressure gauge (CIS) to check your cold control and system pressure. Without using a CIS fuel gauge, you'll be shooting in the dark troubleshooting your engine.

Tony

[coolngroovy]

G'day Tony,
Could it be possible the f.a has been changed at some stage?
I'me scratching my head to figure out why the lines are still in place, & blocked off with bolts.
If it has been changed, would it make any difference? Perhaps wrong f.a?
The weather is still lousy atm, hopefully tomorrow i can get back into it.
It always seems to rain when i have a project on the go!
I may have to add a CIS fuel gauge to my next pelican order.
Cheers m8, Col.