I took my carb off to clean the egr passage's like everyone talk's about doing. Other than just a little black in color, they were surprizingly clean. The carb how ever was another story. I gave it a good cleaning, and put it back on. Now for the first 10-20 second's when you start the car for the first time of the day, it run's really rough. If I rev it up, the whole car shake's really bad. But once it get's warm, or past what ever problem I'm having, it run's fine. I did change all the vacum line's since most were really bad. I have double checked everything, and can't see anything obviously wrong. The choke adjustment has 3 rivit's in it so I can't change that. Oh ya, I did have the carb upside down. My friend say's you should never do that. Is that true. Could I have messed up the float. BTW,, it's a 85 307 with an electronic Q-Jet. Any idea's what I screwed up. Thank's, Cal
I beleive so. I guess I should double check my vacum diagram. But if something was wrong, why would it get better after 20 second's?o No:
Did you do anything mechanically to the carb? Like change the idle mixture screws or something? I would venture to say there is still carb cleaner in one of the passages you blew out. Did you blow it back out with air? A vacuum problem maybe less noticeable after it is warm.
I didn't touch any screw's, or use air. And I've been driving it for a week so any cleaner should be gone.
Its no secret that the computer Q-jet was a piece of junk. We can't really flaw GM. They were trying their best to adapt to the new technology called the Oxygen Sensor. The invent of the Oxygen Sensor would actually allow manufacturors to start producing serious power again while complying with emissions. Problem was the transitional cars like yours. Anyway, my wifes 90 Estate Wagon never ran right with all that, so I converted it to a vacuum advance distributor and a normal carb. The first time I took it for emissions, it blew so clean that the mechanics said I could kill myself in a closed garage with it! Since that one time it hasn't passed without major grief so be warned if you do this conversion. The only thing different the second time was that I plugged what I believe to be part of the EGR system. It was the two "thingys" bellow the carb in the intake manifold. If you convert someday, you may want to leave them there. Luckily, we qualify for mileage waver every year.
If you soaked or used carb cleaner on the vacuum dashpots on the choke side, you may have killed them, they don't like chemicals, especially after 20years of use. Double check the vacuum lines and choke linkages, they're easy to get mixed up and backwards. Been there, doing that!!! James
In a carb. kit, there should be 3 self tapping screws for the choke housing. Just drill out those rivets and replace with the screws.
Sounds like the choke pull off isnt working as soon as it should. My Dads 90 Estate wagon did the same thing, start it up cold, and rum, rum, rum, then it would clear. The choke closes when you hit the gas when cold, then you fire the motor, as soon as it starts, the choke pull off opens the choke plate a bit so the motor doesnt flood. If there isnt vacuum going to the pull-off when its suppose to, the choke will stay closed too long until the choke coil heats, but even then, I dont think the choke will open all the way, and the secondaries wont open if the choke pull off is not working properly. Check to see that there isnt any linkage binding, and also if the vacuum lines from the pull-off are going to a relay or temp operated vacuum switch, or relay. Its been awhile since my computer carb days an dont quite remember how it was set up. If you come up empty, let me know, I'll dig out my 90 Buick service manual:beer Mark
Thank's for all the replies guy's. I haven't had a chance to check it out yet. But I'm leaning toward's the vacum pod. Especially since I really soaked the thing with carb cleaner.:shock: Cal
I think we have a winner!!:beer I checked the choke pull off and it wouldn't hold vacum. So I went to my local bone yard and got one for $2.:laugh: Now I just have to wait until morning to see if it fixed the problem. Thank's for all the help. cal
