83 sc engine turn off

[tom1975]

Hi guys , i had today a strange thing , I went with the car today and park it after I drove 15 min to some restaurant ,after two hours I returned to the car, I start the engine but if I leave the gas pedal the engine shuts down , I drove home all the way and I used Handbrake to not download my foot off the accelerator ,
The car drive fine only when I put off my foot from the gas pedal the engine turn off .
Does anyone have an idea what's going on here?
Thanks
Tom

[timmy2]

First guess is a massive vacuum leak perhaps?
Pop of valve installed?
Check to see if it is seated correctly.

[tom1975]

Thanks ,
Yes I have pop off valve , I will check it,
One more thing , two days before I fix the heating fan near the engine , my be I disconnect something when I pull it out and put it back ?

[tom1975]

Ok , I take off the heat fan and look , every thing look ok, I check the pop off valve and it look also ok,
The thing is that the engine start right up only with ignition switch without touch the gas pedal and work properly , i let it warm and As soon as I press the gas pedal rpm go up fine and I can drive , I take off my foot from the gas pedal and the engine shuts down immediately.
I try to start up again with only the ignition switch and I can't ( if I start the engine with the gas pedal it's ok but if I take my foot off the pedal engine shuts down)
I wait 5 min start again only with the switch and the engine work fine , I Touched the gas pedal start to drive when I leave my foot from the gas pedal and stop the engine shuts down again.
Is there a unit that controls the idle speed columns, it may be dysfunctional?
Eny ideas ?

Thanks
Tom

[tom1975]

somebody ???

[JJ 911SC]

Go over your heating fan repair to see if you did left something unplug.

[tom1975]

I checked and every thing is connected .
Does anyone know what this could be ?
Or someone had the same problem in the past and know how to solve it?
I am despair

[JJ 911SC]

As per timmy2, check for vacuum leak.

Easiest way is to spray "Quick Start" around vacuum hose connection and if the rpm goes up, you found the leak.

[tom1975]

Thanks, I'll see if there is a vacuum leak, do not you think maybe this is an electronic problem?

[mreid]

Do you have cruise control? Are there any other cables or control rods connected to the throttle lever on the engine? Perhaps they were adjusted incorrectly or hung up and the engine adjusted to compensate. You may have returned them to normal when you conducted your repair.

[tom1975]

Yes I have Cruz control and I check it , it's looks ok but I try to disconnect the Cruz control cable and see , I don't think it's the Cruz control but I check it Anyway ,
maybe its problem of some fuse or relay in the front fuse box ?
When I fix the heater fan Before the problem start I play with the relays and the fuse .
One more thing that Could there be a connection, About five months ago I had a problem of mice that entered the vehicle and they make the heat fan problem ,
I had one more strange thing : when I switch on the air condition the engine was shuts down but it's stop Like it's never happened and i make 3000 miles and every thing was good.
i replase the O2 relay month ago becouse cold start problem that solved with the ralay.
I don't know what to do

[tom1975]

here some photos of my love with the mice and after cleaning

[porsche930dude]

make sure the idle screw is there and hasnt backed off aswell as the idle switch right by the adjustment screw

[tom1975]

make sure the idle screw is there and hasnt backed off aswell as the idle switch right by the adjustment screw

Thanks but that does not screw the screw in its place

[tom1975]

Hello everyone,
Today after a week I have not touched the car, was stormy weather, I started the engine, the engine started very well and worked great, I went with the car for a test drive and noticed the car stopped to turn off, what happens now it stands at 900 rpm idle, I press on the accelerator rpm goes well and when I left abruptly rpm drops to the first line, stutters a bit and then the OXS and ignition light comes on for a second and rpm immediately comes back to 900,
The same thing happens to me also when driving the vehicle leaving the gas pedal to shift gears.
What do you think is the problem?
I thought the reason that CD, the relay of the O2 and Coil recently replaced maybe it's a problem of fuel filter or maybe need to make adjust mixture?
What do you say maybe it's the WUR?
The car is from the US
Please need your help
thanks

[jason2guy]

this happened to me once. on the back of the throttle body there is a steel pipe that connects to the brake booster. that connection came apart and the car stalled. stick your hand back there and check if its loose

[boyt911sc]

Tom,

I got your email and read the story about the car. First thing first, get hold of a CIS fuel pressure gauge kit so you could check your fuel pressures. And at the same time, learn how to test run a FP by using the FP relay socket with a suitable wire jumper with in-line fuse. Do not tinker or adjust the fuel mixture setting at this point. The engine is running and that's a good sign.

After you have driven the car for a while, check if the idle speed would change after you removed the oil cap. Let us know the result. BTW, post the numbers on the WUR (0-438-140-xxx). The last 3 digits (xxx) could be seen on top of the WUR just below the vent post. Check also the heating resistance (Ohms) of the WUR. We'll separate the CIS troubleshooting from your electrical problem.

The mice incident could have compromised some electrical wires (?) and disable the AC to eliminate it from our troubleshooting process.

Keep us posted.

Tom

[tom1975]

Thank you tony
what is FP , FP relay socket ? i am not perfect with english and use google translate
It will take me some time to get fuel pressure gauge, as you know I export the vehicle from the United States and it now in Israel.
I'll buy online, you know a website that I buy one at a good price?
This week I'll check the number of WUR,
Currently the vehicle is stored at my parents and they are an hour away from me, so I'll try to update as soon as possible,
I think I will make it this Saturday and I'll check the resistance of the WUR ,I will try to borrow from friends Ohms meter, how much resistance should have to be?
And of course I will take the advice of jason2guy and I'll check the metal pipe.

For the air conditioner, I unplugged the relay in the fuse box To deny it
Thanks guys you really are here when we need you

[boyt911sc]

Tom,

You don't need to remove the WUR from the engine to get the ID numbers. Looking at the engine bay, the WUR is sitting on the left side of the engine sitting by the intake runner #2. Right behind the WUR's electrical connection (plug) is a vent tube about 8 mm in diameter. At the base of the vent tube are the stamped numbers. You'll be reading them upside down if the WUR was installed correctly. The ID # and the value of the heating resistance are critical information. Post them when you get a chance.

Tony

[tom1975]

ok thanks
what is FP , FP relay socket ? i am not perfect with english and use google translate