high rpm issue on rebuild quadrajet

[rytari]

hi ppl.

i have 17059218 quadrajet on top of edel performer in my 86 camino 305.. idle was poor and exhaust smelled bad, running rich at idle + worn out primary shaft holes in baseplate, it had terrible bogging when warm and off idle stumble when cold...

last week i got some rebuild kit for some local shop here.

all parts were cleaned, i took baseplate, check for straightness and fit bushing to primary shaft.

now when everything is back together and carb fitted back on intake.. but.


cold engine, with choke it runs fine,  raised rpm of course, and when fast idle cam drops it will start to run some decent 7-800 rpm, little unstable maybe, trans in gear it almost dies and after driving some mile or so ill get 1500-200 rpm and wont go down. or road it works fine, not any hesitation, not any stumble, motor is pulling much much better.

i cannot get it lower, than 1000 rpm when hot, idle adjust screw wont even touch the primary shafts lever, mixture screws wont affect nearly anything... without air cleaner i managed to get it running some 7-800 rpm again but idle is very unstable,  it can die any time or just changes rmp constantly.

choking primaries with my hand causes also rpm increase up to 2000 rpm for a moment

-i have tried change float level
- car will run still if idle mixture screws are bottomed
- spraying brake cleaner around the carb and intake wont make big difference
- initial advance adjust wont give me any help. 


i don't have any idea where to start.

 


 

[rytari]

it seems that even you guys got nothing to suggest...

[429bbf]

if i was to take a EWAG id say you didnt get your primary plate seeded in the bore square when you put bushings in. now your carb is sucking air past the primaries and not pulling fuel. did you look up into the light when you installed the throtte plates? are they about light free?dean

[rytari]

i centered both plates to the bore as good as i could, shaft is closing but i didnt use any auxilary light to look trough it, only raised against the sky and try to see trought but for my eyes that way those close well and not any gap between bore and plates could be seen.

[Shark Racer]

Are you positive that you don't have vacuum leaks anywhere else?

I would start by capping all the connections on the carb and seeing if that helps.

Also, make sure the manifold is sealing well and that any vacuum ports on the intake are sealed well. I had a problem recently with my car running lean due to an NPT vacuum tee fitting that was not seated well on the 5-7 runner.

[rytari]

no, i think thati cant be 100% positive sure about thati have no leaks... anyway i got 22 hg vacuum but thats approx 7-900 rmp, it varies too much to say exact, intake seals are new, felpro permadry somethign labeled that i used. and also with that higly flamable brake cleaner it didnt ring a bell sprayed over intake or around carb, normaly it will affect rapidly if theres some vacuum leak.

 also i have tried run it with all carb ports and that one that i used from manifold sealed tightly.

[429bbf]

when you installed the carb kit was the lower gasket between the fuelbowl and the throttle plate the exact same gasket?o0r did it have a hole 1/4 size in about an inch from the back of the carb.if you have the old gasket check this can cause a internal vacumn leak.dean

[rytari]

i coulnd be sure about that gasket so i took carb out and opened the base, for my eyes, both, old and new looks the same, and i also try to see some light trough the primaries but, i can say those are not completely tight,  but i think those cant be any better with those plates in that bore, some light can be seen between plate and walls just near the shafts on both sides.

[corellian corvette]

You know I just had the same problem tonight. When I put the baseplate back on the carb, I didn't properly align the secondary lockout lever and the choke mechanism on the passenger side of the carb. The lockout lever was on top of the choke release, preventing the choke from closing completely, keeping me on a slightly high idle. That would explain why the idle speed screw isn't contacting the throttle lever.

[Cliff Ruggles]

Too much initial timing?

Idle tubes removed and cleaned during the rebuild?

Did you install a new float? 

Our kits come with a new float, and the correct gaskets, filter/spring, complete accl pump, and high flow needle/seat assembly....Cliff

[rytari]

i have tried to change timing but that wont give me any help, i can get idle rpm down by turning advance later but it goes too late, got backfire and low power.

i did remove idle tubes yes, but float is old one. rebuild kit didn't include one.  i grind baseplate and inspected that airhorn is good but with the top of the carb out, it seems that my center of primaries is a bit higher than float bowl walls, i think my main body is a bit warped, i don't know what it is when i fit all together but like i said, i cannot find any vacuum leaks outside the carb with using highly flammable brake cleaner.

cliff, how much your kit shipping to finland would be...
 

[Cliff Ruggles]

Rebuild kits are $45.  I'll check with Marie for shipping price, send an email to cliffshp@embarqmail.com with an address to ship to and she'll send a quote....thanks....Cliff

[rytari]

i got answer from marie about shipping... if i add kit+ shipping and add what goes to customs and tax... cost almost as much as i buy a complete factory tbi taken from some 90´s pick-up

have to little rethink again..

[Shark Racer]

i got answer from marie about shipping... if i add kit+ shipping and add what goes to customs and tax... cost almost as much as i buy a complete factory tbi taken from some 90´s pick-up

have to little rethink again..

If you were thinking about doing an MPFI system, I wouldn't try to persuade you, but the QJ is going to beat that TBI up and down the block, especially for power.

[rytari]

If you were thinking about doing an MPFI system, I wouldn't try to persuade you, but the QJ is going to beat that TBI up and down the block, especially for power.

but unworking QJ wont beat, i cannot drive it like that and it takes tons on fuel now..  for you its easy to say when they are not asking an arm and a leg for a gallon