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how can i increase more fuel into carb? and which one is the idle screw?

1K views 13 replies 3 participants last post by  Tech1984 
#1 ·
i have a slight bit unstable idle, and a very slow cold start.. i have reasearched alot about it and it seems the problem for me is probably not enough fuel into the carb.. i know this because i just checked the fuel leveler glass thing on the side of the carb and it looks to be empty... either empty or full hard to tell but i think empty...

i'm prety sure the slight unstable idle and very slow cold start is because there is not enough fuel going into the carb..

so i am wondering what could possible cause to less fuel into the carb? maybe a weak fuel pump??

also i was looking for the idle adjuster screw, i have found so far 3 screws that look like it, 2 on the left side of the carb near the gas level checker, and 1 on the opposite side that has a plastic knob that almost looks adjustable by hand.. are any of these screws the idle adjuster?
 
#2 · (Edited)
I wouldn't go touching those screws. They'll do nothing for you in fuel mixture. That setting is capped and sealed at the factory for EPA reasons.
If you had a low fuel level in the carb, you'd fuel starve on heavy acceleration or inclines. Fuel pump sounds good from here.
How's the tune up? Checked the carb base for any air leaks yet? Sounds lean.
 
#3 · (Edited)
for the tune up, i havnt realy tuned it up, it looks like it has new spark plug wires, and probably new plugs but i didnt check, probably a new distributor also... oil looks ok but overfilled, the dip stick is wrong or something.. not sure if this is what you mean for a tune up..

i did try to check for vacume hose leaks, but not that carb base leak, i dont think i know how to do that.. i havnt realy got a good look at the vacume hoses cause i still cant get that bottom circle peice of the intake off yet, that tube on the back is super tight and i didnt have to much time to do it.. but i did look at the hoses and couldnt find any missing hoses or cracks..

any suggestions on how to check for base of carb leaks?

dont know if this has anything to do with it but there is oil all over the engine top to bottom, i did clean out most of it from the top a few days ago to spot out leaks and pretty sure its coming from the valve covor, i retightened the valve covor and it doesnt look like its leaking anymore i think... pretty sure this would have nothing to do with the long cold start and kinda rough idle?
 
#5 ·
You can use throttle cleaner, but you have to get the base of the air cleaner off so you can use the straw and pin point the area where a vacuum leak occurs.
Be sure to seal off any vacuum hoses connected to air breather.
You can also use propane when checking for leaks. Un lit, of course.
That breather tube can be a bear getting off the base. Try prying a bit with a screw driver and spray some lube on it while twisting and turning it.
The carb base gaskets were always common on these. Pretty sure you find something.
Also, the AAP diaphragm ruptured causing hard cold starts. Do a search for that too.
 
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#7 · (Edited)
so earlier today when i got home i sprayed the carb with throttle body cleaner and there seems to be no leaks... but i did do it with the air filter on.. was to lazy to take off..

i have found a new problem, there is a very light thump while idle when i was checking for leaks... its very light and almost not noticble, almost sounds like a bog... i think this may be causing the unstable idle, the thing is sometimes the idle is super quite and good but other times its kinda rough... im geusing when its kinda rough you would hear the light deep thump noise.... today when i cold started it, it seemed like it started right away, not sure if it was cause i was pulling on the throttle cable to or not...

i am going to check the plugs soon to see if they are ok... not sure if this engine will last long or not..

the thump is a very deep thump but light, hard to explain, it sounds like its coming from the lower part of the engine, maybe the cat? dont know but the car drives good, nice and strong.. hmm maybe the spark plugs will tell me something... ill take em all out and take a pic if they look differnt.


edit - after further research i think i may have a clogged cat converter, explains why there seems to have so less exhaust pressure and smoke coming out.. maybe this is why i head a light faint thump.. wonder if this have anything to do with the unstable idle..
 
#8 ·
ok so here is the a pic of the spark plugs, i have no idea if they look good or not... what do you think, i cleaned them with throttle body cleaner.. test started it afterwards and seemed to have a rough start.. maybe i should replace?? you tell me

i am starting to think maybe i should just not bother fixing the problem and just run it till it dies..


plugs number 1-4 left to right
 
#9 · (Edited)
For spark plugs toys seem to run better with Denso (OE) or NGK plugs. Think autozone or advance carry the standard Denso's. Can't guarantee that would solve any problems just a FYI. You might try checking your fuel pump pressure to see if pump is weak. The fuel level in carb should be in the midpoint of sight glass with engine running. Not sure what the thump sound is you are referring to. There is a very large flat headed screw with ridges all the way around it on left ( drivers side). That is the one for idle adjustment.
 
#10 ·
it kind of seemed like it runs better after i cleaned the plugs, been working on the car today again and tried to run the car without the intake filter and housing to do another leak test, and also check that fuel leveler thingy.. but it did not work, the car bogged down badly so i just shut it off i think or it died.. im not realy sure if it bogged because i jus re installed the plugs and cams... i had new plugs being installed but the damn bitch gave me the wrong ones, never buy parts from a lady..

for the carburatur, i took a look inside of it and the passenger side carb hole looked like there was gas in it? is this normal? i was moving the throttle cable to see if everything was normal, it also smells like gas when i take the filter off, i am not sure if we are suposed to..

after doing a search on white spark plug tips there have been many people who says that could be because the car is running lean(not enough fuel)... i am starting to think my carbs leaking gas or something i dont know, but it does look like its leaking something from the coloration of the side of the carb, if it is a gas leak it must not be leaking much gas i dont see much of a real leak, but only a different coloration of part of the carburator and its kind of near the fuel leveler thing... it kind of looks like a dried up oil leak...

another reason why i think the carb is also not getting fuel is because whenever i give the car gas befor i start it on a cold start, it would start up perfectly..

i am thinking its the AAP diaphram thingy like tech1984 said but i have no idea how to repair, i still dont know how this carb works yet... there is just so many small parts and vacume hoses..
 
#11 ·
It is supposed to have gas inside the float chamber . That's why the sight glass is there to inspect level from the outside. It is possible the float could be sticking and or the needle and seat valve could be worn out allowing engine to get too much gas. If not getting fuel inspect your fuel pump pressure and replace gas filter if haven't done it yet. The AAP valve is an easy fix just replacing the diaphragm.
 
#14 ·
An old trick for the people who didn't want to spend the money was to disconnect the AAP vacuum line and stick a BB in it. That way it wouldn't draw the fuel through the vacuum lines.
Just a temporary thing, tho.
 
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