Hooptie

so I rebuilt my carb last week. ( for my 70 Delta 88 / Quadrajet) very meticulously over 7 hours , to make sure I had everything right. when I put it back on, the car started and ran pretty good. a little bit of a hard start, and had a little hesitation off the line, so I figured the carb would want some tuning after the rebuild. after a day it stopped running all together. motor turns over runs for about 2 seconds, dies and wont start again. the only thing I did not do is adjust the float. only because I can't find the float level information anywhere. could this be causing my problem? as the old needle was pretty flat, and the old brass barrel didn't have the little square windows on the edges that the new one does. I would really like to open it back up and do the float adjustment just to rule it out. but I still cant find the proper adjustment height info anywhere. its a Quadrajet 7040251. if anyone has any ideas what could cause this. or what the float level is, that would be awesome. thanks guys!

oldcutlass

Its been awhile since I rebuilt a quadrajet but there should have been instructions in your kit on how to adjust the float.

68442

Float Setting
After removing the top section. 1/4" down from the top of the housing taken 3/8" in from the end of the float(gasket not in place)

Hooptie

Ok. I'm an idiot, and the paper was tucked in the box that I threw out. it says 1/4" which I think is what I measured the float at when I was putting it back together. or at least close. and another 'I'm an idiot' moment. I got it to run by tapping the front top of the carb with the butt of a screwdriver. I was tapping the back of the carb . this is a learning curve for me. I've rebuilt my fair share of moped and motorcycle carbs. but this is my first car carb. I've got it running now and idling pretty happy at 800 rpm (is this normal?) it seems a little high to me. at least its running now so I can troubleshoot the other problems. thanks guys!

Hooptie

oh also is it normal for the float to stick once or twice after a fresh rebuild on a carb? or will I most definitely be getting back in there to fix it when it sticks again...

Fun71

No, it is not "normal" but there may be some small debris particles from the open fuel line that are sticking to the Viton needle seal.

As for the idle speed, you just disassembled and reassembled the carb, so some adjustment and tuning will be needed.

MDchanic

Do you have a Chassis Service Manual?

All information about rebuilding and setting up the carb, as well as tune-up information, including idle adjustment, is included there.

Most of it is also included in abbreviated form on the instruction sheet from the rebuild kit, including, if I'm not mistaken, idle specifications.

If you don't have it, we can look it up for you to help you get on the road, but you really need to have a manual.

- Eric

Ozzie

My information agrees with what 68442 said. Push down lightly on needle end of float arm to assure needle is seated and hold float retainer firmly in place while making measurement. Bend float arm to adjust.

TripDeuces

One common problem is the placement of the needle clip on the float. Many place it through one of the holes on the float tab, this is incorrect. The needle needs to ride completely vertical in the seat bore. If it gets cocked in there you can run into the problem you are describing.

Hooptie

Yeah, I rebuilt it by watching a youtube video that covers the full rebuild a few times, and while building. so I was careful to make sure the clip was on the edge instead of the holes. but it could have gotten offset or something. I tuned it a bit yesterday and got the idle down closer to 600 and it seems to be pretty happy. if it decides to stick again I'll pull it apart and take a look and double check the float and seat. thanks guys.