fed up with this stupid car

[baxsom]

i am sick of tired of trying to tune this car.

i thought i had everything fixed with the exhaust popping but the damn thing just wont run right.

i am on my second quadrajet now both bought new from jet performance.
both run so rich that even with the mixture screws all the way in the car still runs.

idle screw has the spring completely compressed just to get about 700 rpms.

choke is all the way open
fast idle screw is completely removed
timing is 12 degrees with the vacumm unplugged.

i should have bought the square bore and holley when i had the chance

 

[KANE]

i am sick of tired of trying to tune this car.

i thought i had everything fixed with the exhaust popping but the damn thing just wont run right.

i am on my second quadrajet now both bought new from jet performance.
both run so rich that even with the mixture screws all the way in the car still runs.

idle screw has the spring completely compressed just to get about 700 rpms.

choke is all the way open
fast idle screw is completely removed
timing is 12 degrees with the vacuum unplugged.

i should have bought the square bore and Holley when i had the chance

I get moments where I just want to walk away too.

Do you know of a shop that is nearby? Do you trust that shop? If so... it might be time have someone else take a look at it. It never hurts to have another set of eyes look over it when you are out of ideas.

 

[Vettehead Mikey]

What kind of fuel pump/fuel pressure do you have?

 

[baxsom]

stock fuel pump
pressure according to my inline gauge is 5psi at idle.

there is no one near that will work on a quadrajet. in san antonio you can find a million shops that will tune an EFI and about 10 that will do a holley.

no one will even touch a quad.

 

[fine69]

i am sick of tired of trying to tune this car.

i thought i had everything fixed with the exhaust popping but the damn thing just wont run right.

i am on my second quadrajet now both bought new from jet performance.
both run so rich that even with the mixture screws all the way in the car still runs.

idle screw has the spring completely compressed just to get about 700 rpms.

choke is all the way open
fast idle screw is completely removed
timing is 12 degrees with the vacumm unplugged.

i should have bought the square bore and holley when i had the chance

Hi Baxsom,

I do empathize with you since I often feel the same. I've experienced something very similar to what you're describing. I tuned it, did the timing by the book (JohnZ's instructions) - and I would still get the popping - and even dieseling.

I know it may sound rudimentary, but please check your spark plug wires. I actually had two crossed. I swore they were correct --- but... I was wrong. Also one of them had a small burn and it would arc against the header - which didn't help.

So I corrected these and the car ran great... AND THEN after a few months the popping started again... returning like a faithful old friend! So I re-did the tuning, timing, checked the wiring... no change. Of all things the problem turned out to be the freaking choke adjustment!! Do these need to be adjusted with the change in seasons?... not sure, but that did the trick for now.

Yes, these old cars will drive you nuts. Take a deep breath - walk away - decompress - and then go through troubleshooting as methodically as possible.

Sound like good advice? Hehe - I wish I would take this advice myself at times. Hang in there....

Ralph

 

[minifridge1138]

You could try to get your money back from Jet.

 

[Hib Halverson]

Very little info about the engine is given and that makes it tough to offer much useful advice but if this is a case of the engine refusing to idle properly even though the idle speed screw is all the way out and the idle mixture screws are closed, there's gotta be a leak somewhere. Either there is a vacuum leak, the PCV valve is improperly sized or maybe the timing is off.

Have you verified that the timing marks on the balancer and the timing cover are correct?

 

[baxsom]

sorry
i didnt think the engine size mattered to the problem

it is a stock 454
the mark on the balancer lines up with the 0 mark on the tab when the cylinder is up and both valves are closed. i checked with the valve cover off.

i cant find a vacuum leak anywhere.

i even took the intake off and resealed it to no avail.

pcv inlet is blocked.

brake booster inlet is blocked.

hose to headlights and wiper door as well as tranny is blocked.

no noticable air leaks around the base gasket.

timing is 12 degrees without the advance hooked up.

choke is all the way open.

fast idle screw is taken completely out to make sure that the fast idle cam doesnt get in the way

 

[Bill75]

Try spraying some Liquid Wrench, Carb Cleaner or other similar stuff around the intake gasket with the engine running, see if it might be leaking. You'll hear a change if you find a leaking spot.

 

[JohnZ]

i am on my second quadrajet now both bought new from jet performance.
both run so rich that even with the mixture screws all the way in the car still runs.

If it runs with the idle mixture screws closed, it's getting air when it shouldn't, and fuel when it shouldn't. It will only get air if the primary throttle plate is too far open, and it will only get fuel from the transfer slot (since the idle mixture orifices are closed).

Something is keeping the throttle plates from closing to the idle position, exposing the transfer slots. Check your throttle linkage/cable setup to make sure it isn't holding the carb lever from closing - binding, kinked, etc.; disconnect the linkage from the carb to take it out of the equation and see if the throttle plates will close down properly. If they do, back the idle mixture screws out about a turn to a turn and a half, start it, get your vacuum gauge out, and re-adjust idle mixture for highest steady vacuum.

Then find out what's wrong with the throttle linkage.

 

[baxsom]

i can fully close the throttle plates.
or at least i guess i can fully close them becaust now i can back the idle down enough that the car cuts off regardless of where the mixture screws are.

this is what is happening.

mixture all the way in. idle screw not touch stop.
car wont start. i then screw the idle screw in until it touches the stop and after a turn or two more the car starts up and idles.

idle screw in farther and idle will hit 600 in gear.

so i know the transfer slots are closing because the car is dying if the idle screw is backed out enough but it still shouldnt idle with the mixture screws all the way in.

as a starting point,
i screwed the mixture screws all the way in.
and then backed the idle screws out until the car died.
i then backed the mixture out 1.5 turns and then started screwing the idle in until it cranked.

idle is smoother and i dont get the eye stinging rich smell anymore.
hopefully it is coming together

 

[C3alex]

Welcome to the world of our beloved American Yugo.....in disguise of coarse..:eyerole

 

[baxsom]

yugo thats funny
especially because i saw that movie nick and nora last night and he drove a yugo

 

[Curtis]

After you get it started and idling i would adjust the timeing till the motor is really smooth, then go back to setting the carburetor by vacuum readings. . Maybe it just needs a few more degrees advance.

 

[baxsom]

i have it now right at 14 degrees of advance with vacuum plugged.
with full manifold vacuum plugged in it idles right at 30 degrees of timing.
idle is 600 in drive

vacuum gauge says it is holds a steady 20mm.

i took it for a short drive. seems steady and smooth, no black smoke, throttle response is good.

here hoping its good to go now.

 

[Curtis]

Sounds like you're on the road to recovery.. CONGRATULATIONS

 

[LT4man]

Congratulations on getting your Vette to run right. I know it can be very frustrating to work on these cars. A lot of times it takes patience that we don't have to find the hidden problem.

How did you finally get everything to work properly?

SAVE THE

 

[baxsom]

not sure if it is running properly or not but it is definitely better.

cranks, runs, idles smooth.
no smoking

vacuum at idle is a very steady 20 on the gauge and from what i have read that is really good.

idle in drive is right at 600
idle in park is right at 800

its raining here now so i dont want to go for too long of a drive with it but yesterday it seemed to be ok.

what i ended up doing was advancing the timing a little bit at a time until the idle smoothed out and i was able to back off the idle screw more and more.
ended up at 14 degrees to smooth it out. with full manifold vacuum it is right at 30.

mixture screws are right at 2 out from seated so it may be a little on the lean side but i will have to check the plugs to see if they are fouling.

 

[LT4man]

You do not have to check the spark plugs to be able to adjust your idle mixture properly.

Engine completely warmed up.

Transmission in Neutral or Park.

Vacuum hose connected to distributor vacuum advance unit.

With your vacuum gauge hooked up to intake manifold vacuum, turn a mixture screw in until the vacuum just starts to drop.

Back the screw out until the highest vacuum reading is reached and stop.

Back the screw out another 1/2 turn.

Do the same exact procedure with the other mixture screw.

Adjust your low idle speed to where you want it. You might have picked up some RPMs doing this.

You will have your carburetor mixture adjusted perfectly!

Over forty (40) years experience in the auto repair field has honed this for me.

Just take your time. Enjoy!

SAVE THE

 

[baxsom]

see thats the issue
i can hook up the vacuum gauge and screw the mixture screws all the way in and the vacuum doesnt change.

i know its not because the throttle plates are open too far because the engine dies if i screw it out dropping the rpms.
i took the carb off and opened the idle enough so that the blades were cracked but the transfer slots were still covered.

at first i thought it was a vacuum leak somewhere in the system so i unhooked and plugged the brake booster, tranny, and the headlight and wiper system. i then took the intake off and resealed it just incase. new carb gasket (the 1/4 inch one)

same thing. it runs fine, cranks fine, idles fine, i drove it about 15 miles today and it performed perfectly.
from a dead stop i can stomp the gas and it breaks the tail end loose with no hesitation or i can ease into the throttle and the rpms increase nice and smooth.

wierd wierd wierd