‘74 1.8L L-Jetronic Cold Start Low Idle, Mystery solved! Options

[Van B]

Ok fellas, here’s the run down Aux Air Regulator (AAR) and Cold Start Valve (CSV)/injector both work fine. Many of you have also been keeping up with my high idle issue that we figured out.

But yet, when the car is cold, i.e. room temp, I don’t get the high idle I should on start-up. Instead she cranks a bit and then lumbers to life. Idle lopes around 700-800rpm and then smooths out as it warms.

In all other aspects of operation, the engine seems to be pretty happy.

Thoughts? Experience? (IMG:style_emoticons/default/confused24.gif)

-Van

See post #419 on page 14 for a synopsis of the outcome.

[Van B]

That makes sense to me. That injector definitely puts out a lot of fuel. And the fact that it's constant on while cranking puts the engine at risk of flooding. I could smell raw fuel pretty strong the day my car didn't want to start.

I'm still trying to understand the dynamics at play here from the L-jet point of view. Generally a choke phase would enrich the air fuel ratio. Maybe I'm begging the question here, but why does the idle speed improve after the AAR is closed?

I'll be out of state all week again, but when I get back, I want to pinch off the AAR and see what happens on a cold start.

[emerygt350]

Pull it off the air cleaner and cap it with your thumb. If you can feel it sucking then you know it is working.

[Van B]

Pull it off the air cleaner and cap it with your thumb. If you can feel it sucking then you know it is working.

Yeah, I can play little dutch boy too. First will be some forceps on the short line. Prior to my first crank over. Then if there's nothing different, I'll do as you described.

Like I said on the last thread, the AAR bench tested successfully. Open, closed, opened again. It was a 70 degree day when I tested it so it wasn't fully open to start.

I'm also still really wanting to hear from someone with a 1.8 L-Jet that gets a proper high idle on cold start... I could be chasing fiction.