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-   -   3.0 CIS Fuel Problems (http://forums.pelicanparts.com/porsche-911-technical-forum/201722-3-0-cis-fuel-problems.html)

Mrame 01-15-2005 05:40 PM

3.0 CIS Fuel Problems
 
Hi Guys,

I finaly got my 82 3.0 CIS back in the car after about one year of playing around. I completely rebuilt it.
My problems is the fuel pump will not come on automatically. If I apply 12V directly to it, it fires up and pressurizes the system. the car will start and runs for about 5 seconds then dies after using up the fuel. I have checked fuses and all electrical wires I remembered disconnecting all looks OK.. I need some help here..

john walker's workshop 01-15-2005 05:51 PM

reach in with your left hand and disconnect the green plastic plug on the sensor plate housing. for test purposes. this allows the pump to run with the key on. that is if the rest of the pump circuit is ok. fuse and relay must be good. #6 fuse from cowl, forward. relay, farthest to the rear.

Mrame 01-16-2005 03:53 AM

Thanks John,

I will check that today.

Mike.

Mrame 01-16-2005 03:21 PM

John,

I removed the one on the sensor plate housing nothing happened. Then I began inspecting the colors of the connectors. The green connector was hooked up on the right side of the engine and a blue connector was connected on the sensor plate housing (did I looose you yet).

Once I disconnected the green connection the pump fired up. after about 3 hours or re-routing the wires (my left arm looks like I have been involved in a cat fight). It finaly started.
Does the blue connector fit on the fuel line or on that mechansm on the right side of the engine. Any help will be appreciated. next time I will label everything.

Thank you so much. I have this forum in my favorites and try to read it about 3-4 times a week. You guys do an excellent job. Keep up the good work.

Mike

Jim Sims 01-16-2005 04:05 PM

You have likely mixed up the cold start valve and air flow switch wire harness plugs upon reinstallation. You are not the first to do this. See the below text taken from a previous thread.

If you are connecting the wiring harness plug for the air flow switch to the cold start valve (CSV) instead of the air flow switch, the cold start valve circuitry will ground the circuit, energize the relay coil and cut power to the fuel pump(s). The connector for the air flow switch is higher up and just below the fuel distributor on the front (car's front) of the CIS system; the wiring harness plug that attaches to the airflow switch should be painted green or have a green dot on it. The CSV is down lower on the front side of the CIS system and it's wiring harness connector should be painted blue or have a blue dot on it. If these two connectors are correctly installed then check the air flow switch to see if it has continuity across the terminals. Put a VOM (voltage ohm meter) or powered 12 volt test light across the terminals and lift the air flow meter arm; if there is continuity when you lift the arm then there is a problem with the switch.

Jim

Mrame 01-16-2005 04:36 PM

Hi Jim

I have all the wires right now but the car seems like its getting too much fuel. At startup I have to hold the accelerator all the way down to get it to start.
Mike

Jim Sims 01-16-2005 05:40 PM

The CSV circuit may still be partially disconnected; check that the wires (yellow and red/black) to thermo-time switch on the driver's side chain case cover are hooked up. This switch is part of the cold start valve circuit. Jim

Mrame 01-18-2005 02:43 AM

Is it possible to mix up the connectors to the Throttle Position Sensor and the sensor that looks like an injector on the fuel line. one can smell fuel befind the car when driving and it idles very rough.

Mrame 01-18-2005 02:44 AM

The wires on the thermo-time switch is connected.

Mrame 01-20-2005 07:05 AM

Connector Help
 
http://forums.pelicanparts.com/uploa...1106236732.jpg

the two connectors on this picture is around the heater fan motor. Can any one tell me where the black connector with the red/white and brown wire goes.

john walker's workshop 01-20-2005 07:42 AM

the square black plug (not the one in the above pic) goes to the injector looking thing on the fuel line. that's the frequency valve. blue to the cold start valve, green to the sensor plate switch. running too rich on a 80-83 is often because the frequency valve is not functioning, usually because of a bad oxygen sensor computer relay, or no power to the relay. (interior light fuse). seems like i've written this a lot lately. lots of info if you do a search. the frequency valve will vibrate/buzz when it's working. if the green plug is taken off, the pump runs with the key on, and you can also hear the freq valve buzzing. it's fairly noisy, so it's hard to miss.

cmonref 01-20-2005 04:36 PM

Is the "black connector with the red/white and brown wires" the one in your photo directly in front of the shock absorber tower? If so, that LOOKS LIKE the connector to the THERMOVALVE, and the wire colors are correct for that application. The thermovalve is located just below the bottom edge of your picture. BUT I am not sure that a US '82 SC HAD a thermovalve. It shows up in earlier SC's, at least thru my '80 Euro SC.

Nitrometano 01-20-2005 06:36 PM

fuel pump pressure?

Mrame 01-23-2005 11:48 AM

HI Guys,

Thanks for all the comments/ advice. I have tried all and is a little closer but still not there as yet. This is where I am at right now:

With The ignition on and the green connector pulled the pump fires and the FV starts to vibrate. the problem is the car will only idle (not properly) if I disconnect the FV. With it connected there is so much fuel going to the engine its black behind the car when Started.

What am Id oing wrong. Should I replace the CIS with Webbers?

Please HELP

Mike

Nitrometano 01-23-2005 05:41 PM

what is FV?

Mrame 01-24-2005 03:40 AM

Frequency Valve

Mrame 01-24-2005 03:48 AM

I check for power at the solenoid under the seat, with the key on I have 12V at 87, with the car running ihave 12V on all terminals except for the groung of course.

The ground wires for the harness at the back of the engine. Should it be connected to the engine or the chassis or does it really matter.

Does anyone have a wiring schematic for those sensors, with color codes

Mike

Nitrometano 01-24-2005 10:13 AM

Maybe this can help you:

Frequency Valve:
This component is used only on the engines with Lambda control. The duty cycle of pulses sent to the device by the Lambda control box varies the pressure in the lower chambers of the fuel distributor, which controls the fuel mixture.

Troubleshooting Guide

Irregular idle during warmup:
-Leaks in air intake system (false air)
-Auxiliary air valve does not open
-Cold start valve leaking
-"Cold" control pressure outside tolerance
-Injector leaking, opening pressure too low
-Injected fuel quantities unequal
-Basic idle setting incorrect
-Lambda control system not functioning properly

Irregular idle with warm engine:
-Leaks in air intake system (false air)
-Sensor plate and /or plugunger not moving freely
-Cold start valve leaking
-"Warm" control pressure too high
-"Warm" control pressure too low
-Injector leaking, opening pressure too low
-Injected fuel quantities unequal
-Basic idle setting incorrect
-Lambda control system not functioning properly

Fuel consumption too high:
-Cold start valve leaking
-"Warm" control pressure too low
-Basic idle setting incorrect
-Lambda control system not functioning properly

CO concentration at idle too high:
-Sensor plate and /or plugunger not moving freely
-Cold start valve leaking
-"Warm" control pressure too low
-Basic idle setting incorrect
-Lambda control system not functioning properly

Maybe do you have some problem with the Lamda sensor because it meters the air/fuel ratio. The infomation below will be help you.

For the wiring schematic:
http://members.rennlist.com/jimwms/CIS/CIShome.html

Also check this site for all CIS (K-jetronic) systems:
http://www.phat-gti.com/downloads/boschtech-12d.pdf

Good luck!!!
;) ;) ;)


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