Quadrajet problems please help me!!!!

[Youngbuck7072]

I have a quadrajet carb from a 76 suburban that sat for two years. mounted on my 71 and it acts like it isnt getting any fuel. i have tried everything, changing the fuel pump, all the filters, and it pumps gas right up to the carb so i know the problem is in the carb, does anyone have any ideas??? oh, and what is the tube that runs from the back of the quadrajet by the distributor??

[dmwphoto]

tube that you speak of sounds like the vacumn line to the trans modulator. I'll assume this is an auto trans.
Why did you put the carb on to start with? what was the truck running like before?

[Youngbuck7072]

yah it has a th350. i put the carb on because the previous quad that was on it before, the secondary jet flaps didnt work, the ones the go into the manifold. the reason im asking about the tube in the back is because the previous carb had it clamped off so i just transfered it to the new carb. do you think thats why it wont start? is the vacuum to the tranny important? and the suburban that i got it from had a roll over and he was parting it out, do you think that that has something to do with it??

[Youngbuck7072]

oh and we drove it about five miles after it was sitting for like seven years, and then it wouldnt start, took the carb off and put the new one on, and it still wont start

[dmwphoto]

The best way to figure this all out is to go through all of the basics. As long as there is not an open vacumn port (big vac leak) the no that line is not why you are not starting.
You will need to know if you are getting spark or not at the very least.

[Youngbuck7072]

i am getting spark because when i pour gas down the carb and try to start it it backfires. do the jets possibly need to be cleaned or could there be something wrong with the float since that suburban did roll over

[dmwphoto]

since it did roll over I think you are going to need to have that carb disassembled and gone through or find another one. Should be no biggie to o'haul this one tho.

[Youngbuck7072]

dude im gonna be totally honest, im fifteen, and im scared sh*****s to take a quadrajet apart, cause i heard that if you dont tune them right, they will never run the same again

[dmwphoto]

well then.....
what is the worst that can happen? It does not run now and you already have another q jet. Be brave, use the internet, there are you tube videos on the process. (in fact there is a link to one on here somewhere).
First car I tried to tune up at 18 years old had to be towed in and done right. I have been fixing them ever since and I am 56 now.
Dave

[Youngbuck7072]

k man thanx for the help. im gonna go get a 650 edelbrock with an electric choke from this guy today for 150 and put it on, that way i can move the truck around(it gets tiring pushing it.but if i have a little spare time i might just try to rebuild it, just to practice and see if i can, that way i have a little experience with them

[geezer#99]

You can't put a square bore 650 edelbrock on a spreadbore stock intake without an adaptor. If your present set up tries to fire but backfires instead then your timing is probably retarded. See if you can turn the dizzy by hand. If so you need to set your timing first and lock it down. Advance it is CCW. Retard it is CW.

[Notrodder]

geezer's making a lot of sense there about the distrubutor. Save the $150 for something else and figure out what the problem is with the stuff that you have.

Q-jets are not that difficult to work on and you only need to remove the top to check on the float.

[Youngbuck7072]

well, i just bought the carb, and the adapter plate with the bolts that i need. i drove the truck five miles home with the previous quadrajet that was on it, so im not sure that the timing is off so much that it wont start. what is a dizzy?

[tealgmc]

Take it apart and clean the crusties out of the little pockets that go to the jets. they are at the bottom of the float bowls and when the gas dries out it leaves a nasty crust there that will block your jets. maybe elswhere as well.

[swampfox]

If it starts when it is cold with the choke ,but won't start hot, it might be a bad accelerator pump in the carb.

[Youngbuck7072]

thanks teal gmc. is it easy to get to the float bowls?

[geezer#99]

Dizzy??? Aka distributor.

[BADPURPLE70CHEVY]

Be careful if the carb is flooding and dumping gas. Gas and oil don't mix well...

[Youngbuck7072]

Originally Posted by geezer#99

Dizzy??? Aka distributor.

yah thats what i was thinkining but i just wanted to make sure. havent taken the quadrajet apart yet but i sprayed a TON of carb cleaner in it and the stuff that came out was black but, i still should take it apart and clean the float bowl and jets, right?

[Youngbuck7072]

HAZAA! got the truck running with the carter carb and she purrs....like a lion. im going to take the plunge and buy a rebuild kit for that quadrajet just to see if i can do a rebuild properly, and possibly use it or sell it

[geezer#99]

Well!!! Don't we get a pic of your new carb???

[ChevLoRay]

IF you buy the kit to rebuild the Q-Jet, you'll find a couple of spongy pieces in it. On the outside chance that the one you have doesn't have those, don't throw them away! They have a function, so read the parts list and look at the illustrations.

When I was younger (I'm 63), carburetors scared me to death. As humans, we all have fears, but the only way to try and overcome them is to jump into the thick of it. Right now, you don't have any money in the Q-Jet (so to speak). The kit? Yeah, it'll cost you, but the experience of going through it and "rebuilding" it, will be a good lesson.

Get a decent cleaner. Spray cans might be able to do the trick, but knowing that it has set up for a while tells me that it needs a more thorough cleaning. Gunk makes a carburetor cleaner that you mix and then use to dunk the disassembled carburetor. If you get the right stuff, there will be a metal basket. The carb parts go in the basket and the basket goes into the 5-gallon bucket. When it is clean, and you should plan on visiting the bucket every 30 minutes or so to gently lift/lower the basket several times, it will be time to wash it. I've done this with warm to very-warm water, in the kitchen sink. Wasn't married, at the time, so no problemo. After rinsing it, you'll need some compressed air to blow out the passages. If you don't have an air compressor, use some of the computer-oriented canned air. When it is clean and dry, you can start your reassembly. The instruction sheet will tell you what goes where, and how it should be adjusted. Some parts to look closely at include the idle air adjusting screws at the front of the base. Frequenty, people will screw them in and bottom them out. When that it done too often or too aggressively, there will be a small ring groove towards the tip. That "little" groove will make getting the air adjusted a more difficult task. If needed, replace those screws with new ones. NAPA has a lot of small parts for the Q-Jet, so you don't always have to buy a kit. But, you'll need a kit to start, fo sho.

Good luck.

[swampfox]

When you spray the passages out with cleaner, or blow them out with air ,make sure to wear safety glasses. The cleaner is not fun to get in your eyes, and it is hard to tell where the passage will come out at.

[VetteVet]

Here's a couple of web sites to help you.

http://www.vetteprojects.com/kstyer/quadrajet.htm

http://www.4wheelnoffroad.com/qjet.html

[Youngbuck7072]

thank you guys. all of you. i will try and get the q-jet kit sometime this next week. as for now, i dont know ho w to post pics on threads. i know that you have to have a photobucket account, and then you post the pic url into the space provided, but every time i try, i just doesnt work, any ideas?