I have tried searching and did quite a bit of reading and think I know what my issue is, but want to clarify before I start tossing parts at it.

Problem. Car wont stay running for the first 30-45 seconds of initial startup without babysitting it and constantly giving it gas. Once the engine starts to retain any kind of heat, it smooths out and will run with no issues. Also, choke light stays on constantly. Car runs great once warmed up.

Upon first inspection, I found the choke to just flap in the breeze. The spring appeared to be not engaged at all.

After engaging the spring, it shut, but not fully. This did not help startup very much, but did slightly. I took the car out for a test ride and it ran fine, no power loss, hesitation, etc.

Checked for an open choke upon return of said test ride, and it didnt appear to have moved but maybe 1/4"... certainly not fully open. I tested voltage at the choke and it has 4volts +/- .5v. The alternator looks to be recently replaced and I get a reading of 14.5v when testing across the battery terminals, so it seems to be charging with no issues.

My thinking is this is a bad choke relay. Just trying to confirm before running out and buying a relay just find out it was a waste of time.

 

1. The choke heater spring has a coiled end that surrounds the linkage. It should positively engage the linkage in such a way that the linkage has no freedom to move whatsoever. If it doesn't do this it's probably broken.

2. The Choke light being on is the root of all your problems. Sounds like you haven't had this car for very long, and it came to you like this? As though, the PO perhaps alternate-ethnic-engineered something to hack his way around not finding and fixing whatever the REAL problem is.

3. Here's the schematic for the choke heater ckt. Observe that 12V is supplied to the choke to pull it off, when the relay is in the "normal" (de-energized) state; and that when the light is on, the relay is energized. As long as that light is on, your choke will NEVER EVER work right. You MUST find that and fix it first. Observe how dirt-ball simple the circuit is. When the alt is NOT charging, 12V goes through the Gauges fuse, to the Choke light; the other side of the light is grounded by the brown wire, lighting the light. Note also that the choke relay gets 12V from the Choke-Heater fuse; similarly, when the alt is NOT charging, the relay gets 12V from that path on one side of the coil, and the brown wire grounds the ohter side, operating the relay and DE-ENERGIZING the choke heater. When the alt IS working properly it puts 12V on the brown wire; then, there's 12V on BOTH sides of the light and on BOTH sides of the relay, so neither one operates.

Your first order of business is to fix the alternator so that the light goes out.

Check voltage on the brown alt wire in the small plug with the car running; if it's not 12V, then the alt is defective, whether it charges or not.

 

Thanks for the quick reply. You guessed right... Ive had the car for a week. Previous owner just traded it in for a 2011 Camaro. Seemed to take pretty good care of it other than this problem. I mean it's a one owner with only 84,000 on it and it's super clean. I figure they just ignored whatever the issue was since everything else seemed fine and it runs fine.

I get pretty confused about electrical things. I can solve the simplest of circuits, but once multiple grounds come into play, I get baffled easily.

So, if I understand this correctly and try to break it down into 2 circuits for the sake of breaking it down Barney style.... we can call the brown wire the alternator circuit and blue wire the fuses circuit. If the voltage on the brown circuit does not equal the voltage on the blue circuit, the light goes on.

Alt is bad = light on
Relay is bad = light on
C-H fuse bad = light on
All 3 of these good = light off
That sound about right?

 

So, double update...
part 1. I brought the car to Advanced Auto to take advantage of their free testing service. They decided to test the battery, starter and alternator in that order. Didnt get past test 1 as the battery showed a full charge but only 430 cranking amps instead of 720. Will have to replace the battery next weekend when more funds are available.

part 2: Tested the brown wire at the alternator. Got 14.7 volts. Doesnt mean much to me until the battery gets replaced since I think the bad battery could be putting a different load on the alternator.

 

Last update on this issue...

Replaced the choke heater relay. No more light, choke opens normally.

 

i could be wrong but 430cca should start an LG4. I don't think you need 700 cca thats like new truck starting amperage.

 

True enough; OTOH if the batt he has is supposed to have sufficient capacity to provide 720 cca (whatever that's supposed to mean - I'm an electrical engineer by trade and I HATE that stupidity, wish they still just used PHYSICAL REALITY namely amp-hrs which is literally a count of how many electrons it holds, that other drivel is about like the weatherman giving you the "wind chill" but never telling you the actual temperature), and it only does 430, that's a pretty clear sign it's smoked. Just a matter of time, and probably not much of that, before it hits the magical 0 cca.

 

compression ratio of the engine will make a difference on whether the engine is easier to crank over compared to another

many of the 305 engines actually had a little higher CR than other engine sizes did

some had dished pistions and some didnt,

LG4 and L69 both

also there is two sizes or flexplates flywheels

both making for different engine cranking rpm's

choke light on thats a pretty common sight, also on the early and mid '80s gm trucks

theyre very easy to service and make work correctly again though

 

The car cranks over really easily. Havent had a case of it seeming weak at all. Im eventually going to have it tested again by a different place, as I dont 100% trust the guys that did the first test. The car is running great now (not that it ever ran poorly while the choke was inoperating)