1983 305 Quadrajet HELP

[kj4ltc]

Ok guys, I’m about to lose it...when I depress the gas (engine cold) the choke does not close, it still has full spring tension holding it open.  I don’t know what I’m missing or overlooking.  I also can’t figure out how the high idle is activated.  If anyone has diagrams or anything that could help...I’d really appreciate it!

[kj4ltc]

Before I tried to start the truck today I manually adjusted the choke closed, made sure the vac line for the rear pull off was connected and capped all unused vac ports on the carb.  Truck idled nicely for 15-20 mins before stalling.  After it stalled I waited a little bit before going back out to crank it back up.  Got it to start, and began immediately stalling out.  This is my first carb vehicle and I don’t know where to go next.  I need this truck up and running reliably.

[bd]

Quadrajet E4ME (feedback) or M4ME (conventional)?  Post a pic of the carburetor.  Descriptions, drawings, and adjustments of both styles are in the service manual.

To get you started, perform some basic checks to help narrow the cause of the symptoms.  Don't make any assumptions.  How many miles on the vehicle/engine?  Verify a consistent ignition spark.  Is the spark blue or reddish?  Check the condition of the distributor cap and rotor.  Verify the ignition timing.  Measure fuel pump draw, pressure, and volume.  Use some aerosol carburetor cleaner and spray for vacuum leaks around the carburetor and intake manifold.  Check/replace the fuel filter behind the carburetor fuel inlet nut.  Are the two idle mixture screws accessible for adjustment or are they still capped?  Will the engine continue to run if you mist carburetor spray into the airhorn or hover the carburetor with a shop rag (wear gloves while doing this to protect your hand from backfire).  Performing and reporting on these checks may provide a little more information to help us help you.

[Stewart G Griffin]

Where do you live (for weather reasons, specifically temperature)?

And how did you "manually" adjust the choke closed?

[kj4ltc]

Live in Kentucky, weather is mid 80’s.  I manually adjusted the choke by loosening the 3 screws on the side of the electric choke housing and rotating it until the choke was nearly closed.  Engine ran excellent for 15 mins or so....choke never moved, engine stalled out and after starting back would not idle without me tapping the gas pedal to keep it running.  Got mad at the Q-jet and bought an Edelbrock

[JohnnyPopper]

Too bad, a QJet in good working condition is a fine thing!

[blazer74]

If it never moved the choke coil is bad or no power to it. That’s why it was adjusted wide open because it didn’t work.
Choke pull of plays a part in this also. Pulls the high idle lever down while the choke coil is heating up and opening among playing a part in the secondary operation.
Has to be working to further T/S.
Power Goes thru an oil psi switch and possibly a relay if you have a choke light on the instrument cluster.

[Stewart G Griffin]

did you replace the carb?

[JohnnyPopper]

Live in Kentucky, weather is mid 80’s.  I manually adjusted the choke by loosening the 3 screws on the side of the electric choke housing and rotating it until the choke was nearly closed.  Engine ran excellent for 15 mins or so....choke never moved, engine stalled out and after starting back would not idle without me tapping the gas pedal to keep it running.  Got mad at the Q-jet and bought an Edelbrock

Analysis: 15 minutes brought engine up to operating temperature. Engine stalls out because it's running too rich. Bad bad Q-Jet!!!

Is it possible that some guys don't know what a choke is for? I'll bet he's saving money on gas with better mileage!

[kj4ltc]

I know exactly what a choke is for, what I don’t know is the best way to set choke and adjust carb.  Next thing you know you got keyboard warriors that would rather criticize then offer any help.  Either way the q-jet is off, Edelbrock is on and running flawlessly

[JohnnyPopper]

Didn't mean to off-end, partner.

Seems like you just gave up before anyone could assist, but given your frustration level, I don't blame you.

[Stewart G Griffin]

I know exactly what a choke is for, what I don’t know is the best way to set choke and adjust carb.  Next thing you know you got keyboard warriors that would rather criticize then offer any help.  Either way the q-jet is off, Edelbrock is on and running flawlessly

ok

[blazer74]

You can send me that carb if it’s not remanufactured

[JohnnyPopper]

Beat me to it Blazer!

[SilverMiner]

I know exactly what a choke is for, what I don’t know is the best way to set choke and adjust carb.  Next thing you know you got keyboard warriors that would rather criticize then offer any help.  Either way the q-jet is off, Edelbrock is on and running flawlessly

kj4ltc - Good news, the reason Blazer74 and JohnnyPopper want your carb is because IF it is original to your truck, it is one of the most ideal rebuild & upgrade viable Qjets made. Forget all the nonsense about early 70's GTO carbs - early 80's truck Quadrajets are the best (for certain values of "best").

If you could read off the number from the vertical plate just behind the throttle shaft, likely 17085??? that would be ENORMOUSLY useful. Absent that, a quick photo showing the passenger side of the carb with the air cleaner off would help us solve your problem as well. Both would be best.

Assuming you have the E4ME referenced by BD earlier, that means an electric choke version and there are two fairly inexpensive solutions to your problem, all related to the choke. Based on one of your replies, I'm assuming that is what you have.
#1 - there may be no power to the choke to activate it, and of course then it doesn't work as intended. Remove the clunky power cable attached to the choke, start the engine and confirm using a multimeter that a full 12 volts is present at the choke. Low or no voltage means the electric choke won't work as intended.
#2 - If 12 volts are present in the cable, then the choke coil needs to be replaced, properly adjusted, and you'll have one of the better combined performance/economy carbs ever engineered. Yeah, I'm a Qjet fanboy - no excuses. I could go on, and on, and on about how superior they are to any substitute you might be considering or your buddy's are suggesting. Yes, they require slightly more knowledge and experience to realize their full potential, but I'm of the opinion it is all worth it.