today when I started my car to go to work it fired right up,settled at 2000 then started to climb to 3000rpms. usually it fast idles at 1800-2000 to warm up,but I always kick it down right away to save gas and wear on the engine. it stays at 900-1100,once its properly warmed up I kick it down to 500.this morning it wouldn't kick down at all I was running late for work so I had to throw in drive (very ugly).I know I took care of this before.I can't remember what I did unfortunately.it all worked fine before I put it into storage a year ago,I've had it out for two weeks so far.any ideas?

 

I forgot to mention once it warms up,it runs and starts up fine for the rest of the day.

 

Check your fast idle cam on the passenger side of the Q-jet and make sure it swings freely. I've got a '84 T/A too, and it's had the same problem till I gave my fast idle cam and the shaft it pivots on a good cleaning with Chemtool, and greased up the shaft with graphite (don't use oil, it'll get sticky from the heat and you'll be back to square 1) Also make sure you're not getting gasoline on it- the stuff will evaporate and the varnish that's left behind will make the cam stick, too. If worse comes to worse and that doesn't fix it you might have to pull the carb and take the choke assembly off and clean EVERYTHING good. If you're going to go that far, tho I'd suggest you just rebuild the carb while you have it off the car. Mine still sticks on occasion so I'll have to pull mine someday and just do a teardown on it. Meanwhile I just keep cleaning it with Chemtool and graphite.

Hope that helps...


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Original owner - '84 T/A w/stock 305HO 5-speed

 

thanks dave,I already went nuts with a whole can of carb cleaner,cleaning all of the mechanical linkages ,as usual,sprayed quite a bit down the primary throat. it seemed to respond a little better after that,I'll get it again with graphite,I already have it in the engine oil ,works good there too.

 

Yea I do that too once in a while- run Chemtool in the motor oil for a half hour then change it out. Really keeps the insides clean

Well if you're positive it's not running on the fast idle cam when it's doing that then the only other thing I can think of is to run the diagnostic procedure in the service manual. But it sounds like the carb's gummed up somewhere. Oh, you can also run Chemtool in the gas tank- might want to do that on a few tankfuls and see if that clears up, especially if the carb's never been serviced.

 

I've used Marvel Mystery oil in the gas and oil before but.......... Chemtool?,very interesting.

I mix crazy amounts of graphite with my oil then I just leave it in. its ok 'cause its an old engine,keeps the damage down when the oil gets low.

 

Check and make sure you are getting 12V to the choke element when the ignition is in the run position. If not, that's your problem- no voltage to heat up the choke. You are relying on radiated engine heat to heat it up which takes a while.

If it's not that then the choke element is going bad. Happened to me just a few months ago on one of my carbs. They ain't cheap to replace, either- $40!

 

I read all your comments on the carb problems. Funny thing happened to me in traffic the other day. I was coming off the line from a stoplight and goosed the pedal for some power, but saw the tach go into the yellow (what the F*#$*!!) All i had to do was disengage the gears but it scared the crap out of me. Turns out that the carb got stuck in wide open mode due to poor lubrication!!!!
Thought yall would benefit from this
--Steve S-- 84 Trans Am 305 HO 5 speed, stock

 

I don't know if it is a good idea to add oil or anything to the gas unless you know it is 02 sensor safe. Just my .02!

-Auggie-

 

A sticking gas pedal is a serious situation. Figure out why it happened and fix it.

If it's nothing obvious (frayed throttle cable, obvious linkage binding, etc.) then you problem is likely worn out primary throttle shaft bearings. Both the throttle cable and the return springs pull BACKWARDS on the throttle shaft. After a decade or so this force wears out the primary throttle shaft bearings to the point they can bind and stick the throttle open after a quick WOT run. It's a pretty common problem in high mileage QJets.

 

Thanx for the knowledge. Seems to be running slower now, but it still revs up a bit & won't kick down so i grounded my bird for a week. Thinkin I'm goina rebuild the carb over Christmas or get an Edelbrock (If i have any money left from shopping )

 

Thanx for the knowledge. Seems to be running slower now, but it still revs up a bit & won't kick down so i grounded my bird for a week. Thinkin I'm goina rebuild the carb over Christmas or get an Edelbrock (If i have any money left from shopping )

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--Steve S-- 84 Trans Am 305 HO 5 speed, completely stock will soup up when i get some $$$$$$$$$$

 

mine did this and the secondary air flaps(top) had slammed shut and stuck from the carb air horn being distorted.

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~mike~
1 superclean 86IROC-Z