Cold Start Valve

[82DMC12]

This is a 2-man job, but try this:

• confirm you have continuity to ground on one of the two pins for the female cold start plug
• When a second person cranks the engine (with coil wire removed and inertia switch plunger up), check DC volts on the other cold start plug pin, you will probably 9 to 10 volts. That's good enough.
• Now plug the cold start valve plug in and place the injector into a jar. Put the plunger back down on the inertia switch and crank the engine. The CSV should fire into the jar. If it does, you've confirmed it's oK.
• If it doesn't, try pinching the terminals together on the blue cold start plug, very common for them to get spread apart too far and not make contact with the male pins.

If you know the CSV is working but it still takes a few turns of the starter to get the car to start cold, you are probably very slowly bleeding off fuel through one or more leaky injectors into the cylinders. Can be confirmed by removing all injectors and placing them in glass jars too. Pressurize the system, push down on the meter plate to make them sing, then watch each injector and make sure it doesn't drip afterwards.

You might not see the dripping on a fuel pressure gauge because it happens too slowly. Give it a day or two and you could have a couple of bone-dry injector lines.

[sweetp01569]

The thermal time switch is a bit strange in terms of connections. There are two pins on it. One is a heater (other end of the heater is ground). The other is the switch (other end also goes to ground). So if you try to read across the terminals you will read the resistance of the heater if the switch is close and will read nothing if the switch is open (hot). If the TTS has been connected backwards, 12V was put across the switch to ground burning it out.

Your cold start switch is good.

For a good final test of the circuit, go inside the electrical compartment and find the unused connecter that is hanging around in the back of the compartment. Ground the blue/black wire and crank the engine, see if the cold start sprays now (or see if the car starts cold). Don't be tempted just to leave it grounded all the time or you'll flood the engine when starting hot.

I also have a cold start problem, after getting my car serviced for new water pump, plugs, etc. The CSV will spray with the gray WUR plug plugged in, or jumping the blue/back wires on the electrical compartment plug. Otherwise, the CSV will not spray during normal use. I also attached a picture of a stray unconnected connector that I can't figure out where it connect to. Could CSV not spraying be related? Thanks!

[WHO1DMC]

I also have a cold start problem, after getting my car serviced for new water pump, plugs, etc. The CSV will spray with the gray WUR plug plugged in, or jumping the blue/back wires on the electrical compartment plug. Otherwise, the CSV will not spray during normal use. I also attached a picture of a stray unconnected connector that I can't figure out where it connect to. Could CSV not spraying be related? Thanks!

If you're car is a manual? That connector is for the automatic kick down switch. Un used in a manual of course.



Dave B.

[sweetp01569]

If you're car is a manual? That connector is for the automatic kick down switch. Un used in a manual of course.



Dave B.

My car is a manual. Thanks for confirming that the connector is not needed. I am not sure what to check next regarding the CSV not spraying. The thermo-time switch is new, and is plugged in the correct way. Also, one pin is grounded, and the other looks like 40 or 50 ohms resistance to ground. I thought I read that the TTS can time out if cranking too much? I disconnected the resistor connecto to prevent it from starting. Do I need to wait to try CSV again? Thanks.

[Bitsyncmaster]

My car is a manual. Thanks for confirming that the connector is not needed. I am not sure what to check next regarding the CSV not spraying. The thermo-time switch is new, and is plugged in the correct way. Also, one pin is grounded, and the other looks like 40 or 50 ohms resistance to ground. I thought I read that the TTS can time out if cranking too much? I disconnected the resistor connecto to prevent it from starting. Do I need to wait to try CSV again? Thanks.

The thermal time switch has a heater so it should only work the CSV for 10 to 15 seconds of cranking. On a cold engine it should cool off quickly.

[sweetp01569]

The thermal time switch has a heater so it should only work the CSV for 10 to 15 seconds of cranking. On a cold engine it should cool off quickly.

Thanks, Dave. I'll try it again tomorrow, anyway.

[sweetp01569]

Back at it fresh today, and made some measurements on the TTS installed in the car, and a few spares I had on hand. For the one in the car, one pin read about 50 ohms to ground and the other about 4 ohms, not quite reaching zero. On my three spares, one pin read about 30 ohms to the case, and the other pin grounded out to zero, consistently for all the spares. Thus, I expected the TTS in the car is not right. I switched it out with one of the spares, and the CSV now sprayed properly, and car starts right up when cold. Thanks, again, Dave for your valuable feedback and expertise on this site!
Regards, Paul

[Bitsyncmaster]

Back at it fresh today, and made some measurements on the TTS installed in the car, and a few spares I had on hand. For the one in the car, one pin read about 50 ohms to ground and the other about 4 ohms, not quite reaching zero. On my three spares, one pin read about 30 ohms to the case, and the other pin grounded out to zero, consistently for all the spares. Thus, I expected the TTS in the car is not right. I switched it out with one of the spares, and the CSV now sprayed properly, and car starts right up when cold. Thanks, again, Dave for your valuable feedback and expertise on this site!
Regards, Paul

Glad you got it working. Testing with a meter does not always show the problem. Your 4 ohms with the meter is probably worse when the one amp of CSV current is flowing through that connection.

[David T]

Glad you got it working. Testing with a meter does not always show the problem. Your 4 ohms with the meter is probably worse when the one amp of CSV current is flowing through that connection.

Another thing to note, do NOT use teflon tape on the TTS. It MUST be grounded to work and teflon tape can isolate the switch from ground. As I said in earlier posts, the most common reason for the CSV to malfunction is electrical, usually the TTS but modifications to the wiring of the circuit is also common. The plug swap should have worked to verify the CSV does operate.

[sweetp01569]

I did verify previously that the CSV does work properly, with the plug switch. Also, there was no pipe dope on the TTS threads. I did figure out that there was an electrical problem, but wasn't sure if wiring or TTS (which was purchased new from DMC). Since I had the good fortune of having three spare TTSs from over the years, comparing measurement of each pin to ground (or TTS body) quickly demonstrated that the unit in the car had different resistance readings than the spares (which all had the same readings). It was easy to swap it out with one of the spares. The CSV immediately sprayed and worked fine. Now I need to see if I can get a refund for the faulty TTS from DMC.