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Old 05-09-2013, 12:36 PM
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Rochester Quadrajet trouble

Hi.

I'm having some trouble with the quadrajet on my 77 camaro.
It won't run clean, and when i try revving it goes even rougher and slowly builds up revs.
I'v had this problem since about 2 months after i installed the carb along with a new intake (edelbrock torker II).
The weird thing is that 2 days ago i "reset" the carb (mixture etc) and got it running perfectly! but after 1.5 days in the driveway the problem has come back, and now it won't even run at idle, it just dies, and i'm only able to start it again if i push pedal to the metal
I have tried adjusting the ignition, and though it got slightly better the problem remains.

I'm only 22 and living in a country where american cars cost as much as houses (sweden), so any wisdom you can share is much appreciated.

//David.

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Old 05-09-2013, 02:26 PM
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It sounds like the choke may be sticking or out of adjustment. Temporarily wire the choke lever open and see if it corrects the problem. If so, you can trace it down from there. May just be a choke adjustment problem. Q jets are good carbs. Don't give up on it.
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Old 05-09-2013, 03:39 PM
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Quote:
Originally Posted by cal1320 View Post
It sounds like the choke may be sticking or out of adjustment. Temporarily wire the choke lever open and see if it corrects the problem. If so, you can trace it down from there. May just be a choke adjustment problem. Q jets are good carbs. Don't give up on it.
The choke is actually not plugged in at all (it's electric), i only use the car in the summer and it starts very easy so i was told i could just remove the cable.

But i'll definitely check if it helps to wire it open first thing tomorrow! Thanks for the tip!
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Old 05-09-2013, 04:31 PM
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sounds like fuel starvation issue.
The Quadrajet is a great performance carb so...
First I would check the filter in the fuel inlet housing, that is the big nut where the fuel line screws in.
Be sure it is installed correctly and mostly that it is clean and will allow fuel to flow.
Next i would check fuel pressure.It should be between 4.5-5.5 Lbs.
You will need a gauge that has a small scale to check it acurately.
A gauge with a 0- 10 or 0-20 PSI should work.
Next perform a volume test.
Have a friend crank the engine with a catch can to catch the fuel from the line that screws into the carb. Have it unhookd and run it into a can. Crank the engine to see how much fuel it delivers.
Crank the engine about 7-10 seconds. It should supply 8-12 ounces with no trouble.
If all that checks out then the carb could be very dirty inside and need a good rebuild.
Post back what you find.
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Old 05-09-2013, 09:07 PM
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If your electric choke isn't hooked up and it's not wired open then the choke blade will close and run rich.
It needs 12v to it to heat the coil to open the choke.
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Old 05-10-2013, 07:20 AM
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I blocked of the choke and now it runs perfectly revs and everything! Thanks!
only problem now is that the in gear idle is to low, when it's warmed up and in park/neutral it sits on 1000-1100, but when i put in in drive it drops to about 450-500.

how do i adjust this? there must be a way to change the in gear idle without changing the regular idle?
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Old 05-10-2013, 07:41 AM
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What's your initial timing set at?
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Old 05-10-2013, 10:15 AM
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i don't remember to be honest, i borrowed tools to set it and forgot to write it down when i was done
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Old 05-10-2013, 11:06 AM
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OK!!
Get a timing light, plug off the vacuum line to your distributor and set your timing at 12* btdc. Hook your vacuum line back up to manifold vacuum. Turn down your idle on the carb. You should get it to idle at 700 rpm. And it should idle at 550 in gear.
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Old 05-22-2013, 04:21 AM
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Sorry for not responding until now.
I got a timing light, but when i went out to check the timing the car wouldn't start! i quickly realized i didn't have a spark, and after testing the ignition coil i found it was burnt out.
So, i ordered a new coil, along with a new rotor and cap and installed all of it but the freakin thing still won't start!
could the ignition module have gone bad? how do i check if it's bad? i'v also noticed a capacitor under the rotor wich i think might need changing?
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Old 05-22-2013, 08:56 AM
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We're assuming you have an HEI but take some pics for us. Who knows what dizzy you have?
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Old 05-22-2013, 08:23 PM
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Originally Posted by Davex View Post
i'v also noticed a capacitor under the rotor wich i think might need changing?
If you have an HEI distributor, the capacitor (circled below) is to prevent static in the radio (RFI). They rarely ever fail.

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Old 05-23-2013, 01:57 AM
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Yes, i have an HEI, thats exactly how mine looks, i'll snap some pictures of mine as well when i get out there later today (still morning in sweden)
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Old 05-23-2013, 11:18 AM
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For some reason my phone wont connect to the computer, so i can't upload the images i took. but it looks pretty much exactly like the image Cobalt327 uploaded.

I got a new module and capacitor (maybe at least my stereo won't sound so bad ^^)
The problem remains though. Weak/no spark (the timing light doesn't flash at all, but i have another light that you put between the wire and spark plug and that one flashes faintly), the engine gets fuel (won't start with start gas (is that what it's called in the us?) either) and the distributor has power.
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Old 05-23-2013, 11:27 AM
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make sure that after you have changed the cap and rotor that you put the plug wires back on in proper sequence...also that the cap is on correctly and that you have installed coil properly (button isn;t jammed crooked-coil blabes made it all the way through the cap-you dont have the hot wire plugged into the tack spade-ect) test for power going into the coil and if there is power then there should be spark unless the module has burnt out and that is tough to do on a GM HEI...should spark...coil brand new or used unit?
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