91 GM 302 hard start

[owo2]

Been having some trouble starting when the temp falls below 10 degrees or so and the car is left out over night............

Will crank and catch but immediately revert back to cranking and then catch again and then back to cranking............etc...........

I have had to depress the gas pedal about 1/4 to get it started........


When it eventually does start there is no fast idle and I need to depress the gas pedal to keep the rpms up for 2-3 minutes............

Frozen idle/air valve????????????

[6502dude]

(a) Check coolant temperature sensor - it is located on top of engine on 302. If defective it may not be telling EEC that it is cold out and air/fuel mix needs to be richer


(b) Check distributor cap for cracks - you may be getting condensation when temp drops overnight.

[owo2]

Everything works fine, fast idle on cold start above 10 degrees........below 10 degrees comes the problem starting........it cranks fine no matter the tempt, it cranks, catches, but doesn't start.......I have to repeat the procedure 6-7 times while depressing the accelerator a bit until it does start and then have to use the accelerator to keep the rpms up for a minute or 2, then everything is fine.........

[6502dude]

Hmmmmmm, problem seems to be temperature related - engine not fast idle when below 10 degrees, and keeping engine running.

Years ago, we had manual chokes to set idle high when cold outside.

Now we have sensors which tell on board computers to set idle rate high.

This would be first place I would check out (plus wiring to sensor).