cold start solenoid

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dcefali
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cold start solenoid

Post by dcefali » Wed Mar 29, 2006 7:54 am

I have been having a hard start problem with my 1986 GTV6 and have discovered that my cold start valve (7th injector) is not squirting gas with a cold motor. I tested it by pulling the injector out of the back of the manifold and cranking the motor. No gas. I have 3 cold start sensors and 2 injectors I have swapped out and no combination works, so it must be the wiring. I noticed that there must have been a problem at one time because the harness plug to the injector was replaced and has a crimp splice connection. two wires go in one side and one to the other.

Is there a way to check the wiring to see if I have a break in the wiring some where? This looks like a pretty simple circuit. I read that the L jet system cold start injector parts do not even pass through the L jet brain, so it's a stand alone circuit. What's the best way to trouble shoot?

Thanks

Doug
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DaveH
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Post by DaveH » Wed Mar 29, 2006 8:30 am

Doug,

Check out the BMW 528i L-Jet schematic I attached. It's a bit easier to read than what's on Cardisk.

Do you have 12V and gnd at the CSV? I suspect you don't have a good ground from the thermo time switch. It is what switches the CSV on and off. I'm not quite sure but it looks like the ECU provides the 12V from pin 4. So perhaps it does play a role? Either that or pin 4 just monitors the TTS state.

Dave
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Post by DaveH » Wed Mar 29, 2006 8:32 am

...or I can just email it: davidphicks 'at' hotmail 'dot' com.
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dcefali
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Post by dcefali » Wed Mar 29, 2006 6:58 pm

Thanks for the info. Boy do I feel stupid now. I recently did a 3.0 engine swap. which explains why the plugs were removed.

After some continuity testing and wire chasing...it Turns out that Bosch injection may be fool proof but it's not idiot proof. i had the CTS plug connected to the thermo time sensor and the thermo time sensor plug connected to the CTS sensor. And Bosch even color coded everything so you can tell where they plug in! But when everything is old and dirty it's hard to see the color coding, I switched the plugs and it works great again.

Pin 4 is is traced through the relay to the starter motor. So while pin 4 might be a monitoring point, the power source is the starter motor circuit. Once you stop cranking the cold start injector loses power even if the thermo time sensor is still open.

Thanks

Doug
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