I installed a rebuilt 74 qjet into my 68 riviera which has a 72 455 from a buick centerion. Now my question is when I installed the qjet the engine was racing and I hurried up and shut the car off..What did I do wrong? Now it previous had the carb from the old 430 in it...Now I noticed two holes that say alt and stand and on the bottom stag...where do I put the linkage and should that stop the engine from racing or is my idle turned up way to high?Now I never messed with the carb and when I got it I installed it rght away so I'm thinking I messed up....help
I once tried to put a store bought rebuilt Q-jet on my Riv. The linkages on the R side were longer than the origional carb and hit the manifold when it was fully tightend down and held the throtle open a tad which caused the engine to race on start up and not idle down. I used 2 thick gaskets under the carb to raise it enough to get free movement on the linkages. The carb was still crap and I returned it. Had a board member TechG8 /Everyday Performance rebuild me a nice 800 CFM for me. Its Sweet!
On the rare occassion that I might have a backfire the wire clip holding the rod to the choke plate somteimes disappears (actually it's been engulfed by the engine -yikes!). Anyway, that rod must be reconnected to the choke plate. If not it allows some other connection to go unchecked and the engine races uncontrollably to high idle.
now I added another gasket so I'm using two gasket now and now the idleing been cut in half but still racing at the 2 level on my rpm guage...now I wonder if I should add the qjet carb spacer that is one inch tall? Will that work or should I just drive it to the shop in april once all the road salt is gone? Or should I remove the carb and drop it off or will a spacer work? Another question is can I tinker with the idle screw to turn the idle down?
Of course. That's the first thing to check, it may simply be holding the primaries open too far. Can you verify that your throttle return spring is holding the throttle linkage against the adjuster screw as it should be? Devon
my friend hooked a carb linkage upside down on a holley one time and tached it out when i started it. if its only at 2k move the idle speed down.
I once had a problem after rebuilding my Q-Jet where it seemed like the idle would be high one minute and then normal the next. I managed to hook the throttle return spring at a different hole and it was binding against a bracket, preventing the throttle from fully returning.
If you cover the carbs throat when running will she die out? On one rebuild I had an internal leak and had the same issues you mentioned.
Set the idle mixture screws to get highest vacuum reading on a gauge in gear with the wheels blocked and vacuum advance plugged.
Ok update. Since its nice out. I finally got back to checking up on the carb and taking some of the advice I got and it still not working right...when its in park it idles at 2000 to 3000 but once I drop it into drive it drops down to 1000...now I notice the car is way more powerfull then it was before when I had the old carb on but nothingi seem to do makes the idles drop down futher...now I turned the idled screw all the way down and back and it was no chhange in the idle...now when I turn off the car the engine keeps running for a few seconds...now I am gonna take it to a pro shop that only works on carbs so my question is can I drive my car there with no worries that I will blow the engine? Yes I have a rrpm gauge so I know the redline is 5000...now its straight freeway there and about 5 to 7 miles away from my house....so would I be okay or just call a tow truck? And yes I ordered the carb book and it should arrive sometime next week....
When you get the carb book you and find that it goes into detale about how the q-jet works you more than likely will be able to tune the carb better than the shop u are going to take it to. Before you even adjust the a/f mix screws you will need to hook up a vac gauge and then turn them out until you get the highest reading. But when you get the book you will see there is more than a/f screws that have anything to with the idle
Also if your gonna have them set your carb see if they will set the timing aswell and save you the headach. They should be done at the same time
O I'm going to do that...the book should be here by next week and regardless not driving the riviera on the streets until we get some heavy rain to wash all the road salt away. But on the off chance that I have to take it to the shop after I get the book is it safe to drive it. To the shop? I would hate to blow the engine trying to save 100 dollars by driving it
