‘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.

[wonkipop]

mine does the same.

have done all the checks back a couple of years ago.
all perfectly timed, valves adjusted etc.
aar working and checked.

mine starts promptly and strongly. the cold start injector works and its thermoswitch as well.

once the cold star injector cuts out it goes down to a weaker idle below or at about 800,
then it comes up nice and steady after about 5 minutes.

i just let it warm up for 5 minutes before i drive it.

i'll be interested to see others answers to this one.

one thing you can check is the cold start injector and its associated thermoswitch.
i can dig that data up for you later.

there is a bit of myth around that the cold start injector only comes on below a certain termp. like an on off switch. i don't believe this is so. i believe the cold start injector operates fully below a certain temp for its full timing and above that temp the thermo switch progressively times it on for less and less duration - right up to a cut out temp which is relatively high. i will dig out all those various temp ranges for thermo switch later and post them up. others can chime in on the cold start injector/switch.

i think mr. perrine will have the facts on that.

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