jumping cold start valve turns engine over

[jelp2]

Hi all

First off I'd like to say this is a great forum and it's helped me a lot! This problem though I couldn't find in the search....

So I have a 1978 z pretty much all stock and it's been sitting in the garage for almost 30 years. I've been working on it the past month. I'm switching out a cheap fuel pump I put in just to see if I could get it up and running. It did but fuel pressure is low. I really think the pump is gummed up, the gas was nasty in the tank and even after siphoning it out I think everything is just coated with gunk. So anyway, I'm jumping the cold start vale terminal to depressurize the line, which I have done over the past month without an issue, but this time the engine is turning over! I've had the fuel relays, ignition relay out to clean and check. Could one of them be bad or shorted causing this issue? Any ideas would be great.

Edited November 16, 2020 by jelp2

[Dave WM]

don't understand what you are saying. Jumping the cold start vale terminal? the engine is turning over? you mean something your are doing is causing the starter to engage?

It maybe possible to energize the starter solenoid by applying power to the positive side of the harness that plugs into the CSV I suppose, IIRC they share a common lug on the ign switch "start". But if that is what you are doing that is the incorrect way to activate the CSV to depressurize, You only want to apply power to the csv, not the harness, and frankly you don't need to do that, just put a rag around the fuel line at the fuel rail and loosen the hose clamp. there is not that much fuel stored, the rag will catch it and keep it from spraying.

Edited November 16, 2020 by Dave WM

[siteunseen]

What is the issue? The csv is like a short run fuel injector for adding fuel on start up. Are you getting to much fuel, not enough? You can unhook by pulling the electrical plug off or plug the fuel line to it also. Where I live it's warm enough that I have mine deleted. Car cranks and runs fine.

[jelp2]

What I'm trying to do is just depressurize the fuel line by jumping the terminal plug of the cold start valve so I can do some work on the fuel lines. The engine shouldn't crank when jumping the cold start valve plug,  it should just click and release pressure, not crank the engine. So I don't know if there's a short somewhere or a faulty relay that's causing the engine to crank.

[siteunseen]

You could pull the coil wire. No start for sure.

I always wrap a towel and pull the fuel filter hose up front, fyi.

Edited November 16, 2020 by siteunseen

[jelp2]

3 minutes ago, siteunseen said:

You could pull the coil wire. No start for sure.

I always wrap a towel and pull the fuel filter hose up front, fyi.

I Have pulled the filter hose with a rag as my main method, I'm trying to go by the book this time. Lol  My worry is if there's a short or a bad relay ( stuck open/closed) that's turning the engine that that could be a problem in the near future.  I'm no good with wiring and relays and was hoping someone had a similar issue with a remedy.

[Zed Head]

10 minutes ago, jelp2 said:

What I'm trying to do is just depressurize the fuel line by jumping the terminal plug of the cold start valve 

Describe this "jumping" procedure.  I don't think that that's standard practice.  Sounds like you're causing a dead short across a plug that expects a load.  

[Zed Head]

Here is standard practice.  If you do this without disconnecting the plug you might be backfeeding the ignition switch or some odd thing.  Maybe you had the key On whereas before the key was off.

[Zed Head]

[jelp2]

15 minutes ago, Zed Head said:

Here is standard practice.  If you do this without disconnecting the plug you might be backfeeding the ignition switch or some odd thing.  Maybe you had the key On whereas before the key was off.

Oohhh sh*#*#*    that's showing the terminals on the cold start valve itself. I must have been inhaling too many gas fumes! I was touching my jumper wires to the plug not the terminals on the cold start valve! The scary thing is, is I've done this correctly many times. Thank you

[Zed Head]

Maybe you've discovered a built-in remote starter switch.  Who wants to explore this further?

[jelp2]

Just now, Zed Head said:

Maybe you've discovered a built-in remote starter switch.  Who wants to explore this further?

Lol. I was thinking that, could come in handy for sure.