Mindboggling idle issue

[josh_t]

I've been having frequent and random carb and ignition problems lately. I've figured out the ignition problem and its easy to fix if and when it happens. The carb however, has me scratching my head. It will not run with the idle mixture screw more than 1/2 turn out. I take that back, it will run but it sounds almost like its cammed and it just misses at all RPM's and throttle angles. Either way, the engine runs best with the screw all the way in. As in bottomed out. I have never ever seen anything like this before and it makes no sense whatsoever. I assume the idle circuit is to blame but every time i go to try to clean anyything it turns out that it was never dirty in the first place and it run no different. There is nothing like dirt or rust in the fuel bowl anymore, that problem is long gone. It's not an ignition issue this time either, its not like a normal misfire. Occasionally it will backfire if i have it WOT.

[I'm BLUE]

Kind of carb ???

 

Do you have a sunk float?

or very worn out needle/seat?

or very very high fuel pressure ...?

Have you drilled or changed the jets ??

 

What do your plugs look like? Rich?

 

I guess it doesnt make sense to me. As far as I understand ...No carb designed with idle jets should be able to run with idle screw(s) all the way in on a stock setup. In holley 4bbl carbs this is how you test to see if the power valve is bad ( turn in screw full seat ... if keeps runming power valve is bad by letting gas through when it should not ).But i am def not famaliar with your carb/engine type if a-series.

 

Did you ever replace the points/condensor? Lol

[ggzilla]

You have a fuel leak.

 

Did you take the carburetor apart, as in the separating the throttle body from the carburetor upper body?

[josh_t]

I haven't separated this carb before, But now that i think about it that makes sense. Is it rebuild time? The accelerator pump piston is on its way out anyways, although it hasn't been the cause of any running problems. I wanted to get everything squeaky clean and lubed up too so i guess this would be the time.

 

DTP: new distributor from redbanner so yes new points, condensor, cap, rotor. I still want EI really bad. The points have been a big problem lately since they aren't quite brand new and i dont have a dwell meter and dont want to buy one.

[ggzilla]

Don't do it. That's when these unusual problems occur, is after someone messes with the carburetor.

 

I have seen carburetors that won't run unless the mixture screw is all the way in. It is caused by a fuel leak. Could be a bad power valve -- more more likely a loose part. I would do this: without disassembling the carburetor, make sure every visible jet and screw are tight -- but do not overtighten -- just use two fingers to make sure they are not loose.

[josh_t]

ok. i did have a problem with the power valve being loose about a week ago but i'm positive it's tight now. i'm hoping the screws between the base and lower bowl section are loose. that would pretty much fix any of my engine problems if it still sealed properly. if thats not the case, i am going to rebuild it. i have a service manual so i know what to set everything and i'm usually pretty good with rebuilding carbs and having them right the first time. but i'd like to avoid it if possible.

[ggzilla]

I have never seen B210 carburetor where the base-to-body screws were loose. But there are only three screws and you don't need to take it apart to check. But you do need to remove it from the engine.

[I'm BLUE]

DTP: new distributor from redbanner so yes new points, condensor, cap, rotor. I still want EI really bad. The points have been a big problem lately since they aren't quite brand new and i dont have a dwell meter and dont want to buy one.

 

Don't be fooled a good points system run very well if in good condition and adjusted correctly.

Dwell meter is best way but feeler gauge is good enough :).

 

A slightly leakying/seeping accelerator pump will start to show symptoms ...

A bad accelerator pump will cause you *driveability* issues = stumbling/missing/flat-spot on acceleration.

A completley shot accelerator pump will make the vehicle almost unbearable ( been there) ... literally can't get out of its own way no matter what size the rig.

 

GGzilla seems to have pretty good idea/experience here on these carbs. x2 on do not overtighten!

[datzenmike]

When idling look at the front of the carb. Is there a glass bull's eye? How is the fuel level?

[ggzilla]

i did have a problem with the power valve being loose about a week ago but i'm positive it's tight now

If you got that power valve really tight, that is probably the reason for the fuel leak. They are easy to overtighten and will then leak. They only need about 2 ft.lb. torque.

[josh_t]

When idling look at the front of the carb. Is there a glass bull's eye? How is the fuel level?

right on the dot. i just lowered it from the top of the glass or even higher at times. it didnt really change anything about how it runs.

If you got that power valve really tight, that is probably the reason for the fuel leak. They are easy to overtighten and will then leak. They only need about 2 ft.lb. torque.

i didnt get it too tight. i really couldnt get it tight since i had to use a skinny flat head on one side of the slot instead of the proper tool. its probably not much more than finger tight.

[josh_t]

Its definitely leaking around the gasket you mentioned. but the screws aren't loose at all. i ran it about 2 hours ago and still in the barrels around that gasket is soaked and down inside the intake there is gas everywhere. and the accelerator pump isnt working right at all because the piston is torn on one side. and both barrels have gas on the throttle plates.

[josh_t]

so i rebuilt the carb, and that fixed a ton of stuff, then i found the hose going to my transmission modulator was leaking pretty bad so that fixed a little more. then i have my stupid points problem again. the coil is getting 6 volts after the resistor like its supposed to, and the points are clean and all other electrical parts are clean but the points wont stay clean and my coil keeps getting hot. i have the point gap set at the chilton manual spec of .020, timing at 15 BTDC, i know its advanced but it doesn't keep the points clean any longer when its set at 10 BTDC. the distributor is fairly new. there is no resistance from the coil negative to ground when the points are closed, and they aren't shorting to ground. it seems to be fixed for right now but i bet as soon as i go start it tomorrow, it'll run like garbage and progressively get worse until i clean the points and then it'll be fine. The tiny bit of corrosion that comes off of the points when i clean them doesn't seem like it would do much but it makes it unbearable to even attempt to move the car.

[ggzilla]

Points are not supposed to stay clean. They will darken from use. Coils get warm during use too. If you have no other symptoms I wouldn't worry about it.

[josh_t]

i know they aren't supposed to stay clean forever, but i cant drive it for 15 minutes without having an issue with them.

[ggzilla]

What kind of issue?

[josh_t]

the points get a very slight amount of white corrosion on them that will cause it not to want to run. i'm gonna drive it around some more tomorrow and see if maybe the combination of previous carb and intake problems were the majority of what was making it not run. i'm hoping i dont have any trouble, either way i'll let you know.

[josh_t]

the verdict is in. it worked ok for about 10 seconds and then it started acting really dumb, i'll let the pictures speak for themselves.

 

 

what could cause such a thing?

 

EDIT: i also tested from coil + to battery - and i got 11 volts. my ballast is 1.8 ohms and my coil is 1.3 ohms on the primary side. i tested the secondary side within the last two weeks and it was around 11k ohms.

[ggzilla]

A bad condensor can cause such a thing. Has it been replaced in the last year? New points come with a new condensor.

 

Testing the voltage alone doesn't tell you much because it depends. If the points are open you will see battery V at the coil. If points are closed you should see about 6V at coil.

[josh_t]

the distributor has less than 1000 miles on it according to redbanner. i got it from him and it all looks brand new still.

[ggzilla]

What about the condensor? Have you tried a new one (or even an old one)? They go bad as often as points do.

[josh_t]

i dont want to get into separating the condenser and points as they're wired together, but i have an old set of points and a condenser but the points are pitted so i'm almost positive that condenser is bad. would high resistance on the primary circuit cause the pitting too? my old distributor had high resistance due to a rusty screw on the terminal going into the side of the distributor. if i had the money i'd say screw it, and get an EI distributor off rock auto.

[I'm BLUE]

 

DTP: new distributor from redbanner so yes new points, condensor, cap, rotor. I still want EI really bad. The points have been a big problem lately since they aren't quite brand new and i dont have a dwell meter and dont want to buy one.

 

Please clarify that again for me thanks.

 

the points get a very slight amount of white corrosion on them that will cause it not to want to run. i'm gonna drive it around some more tomorrow and see if maybe the combination of previous carb and intake problems were the majority of what was making it not run. i'm hoping i dont have any trouble, either way i'll let you know.

the verdict is in. it worked ok for about 10 seconds and then it started acting really dumb, i'll let the pictures speak for themselves.

 

 

what could cause such a thing?

 

EDIT: i also tested from coil + to battery - and i got 11 volts. my ballast is 1.8 ohms and my coil is 1.3 ohms on the primary side. i tested the secondary side within the last two weeks and it was around 11k ohms.

 

A bad condensor can cause such a thing. Has it been replaced in the last year? New points come with a new condensor.

 

Testing the voltage alone doesn't tell you much because it depends. If the points are open you will see battery V at the coil. If points are closed you should see about 6V at coil.

 

1st gen (S30) is very very small inside (sub-compact size). High prices.

2nd gen (S130) is for comfort and looks. Bargain prices.

 

the distributor has less than 1000 miles on it according to redbanner. i got it from him and it all looks brand new still.

 

Agreed with ggzilla.

 

The thing about "new" and especially re-manufactured parts is this ..

 

 

 

 

 

 

 

 

 

 

 

That they can be bad straight out of the box !

 

Points and condensor included.

 

Coils can get weak but replace all connections first.

[josh_t]

oh wait a sec, i just realized that the condenser wire screws on to the points. <_< my points themselves look fine and the multimeter says their fine, so i should probably just get a new condenser?

[ggzilla]

would high resistance on the primary circuit cause the pitting too?

No.