tothehilt wrote:
I was hoping you would answer as the various threads that you weighed in on were my main resource for bringing the idle down. I thank you. I also have the Haynes manual, which was not of much help. I found the photos of the GM service manual for the 1 liter 3 cylinder engine on this forum and used them. That and the thread where you posted a picture of the carb with arrows pointing to the various idle adjustments:
viewtopic.php?f=31&t=35778
It appears you do your homework.
I like your effort, and applaud your results.
There are a few more threads which give better pictures of the adjustment screws and there are several posts which detail the fastest way to adjust them and in what sequence they should be adjusted.
tothehilt wrote:
I didn't get it at first (I have never worked on a carb before and wasn't receiving any useful info from the mechanics who sold the carb to me or my local backyard mechanic), it wasn't until I pulled the carb off and looked again that I saw the idle cam adjusting screw. Somehow couldn't see past the grime on my old one, or I would have been spared the extra work.
Don't feel like the Lone Stranger.
We ALL had to learn.
Yes, even me.
I am not ashamed to say that I learned a lot from this site and also from professional carburetor rebuilders in Los Angeles.
There are several fellows now active who are pretty decent with these carburetors.
mkc1962 and glacierburst have some excellent threads; check them out!
tothehilt wrote:
So you are saying that the choke position is fine? It certainly runs well. The backyard mechanic I referred to, who works on a lot of carbs, is bothered that it doesn't open more, I was happy enough as it was.Still wonder why I can't get the cam follower to match up with the mark on the cam. On the old carb it is way off, and I see no way to adjust it. It isn't anything i need to know if its working fine, just curious, since the service manual says to make sure they are lined up but doesn't tell how to adjust it if it is not.
You are correct.
I am saying the choke position is fine.
Better yet, I will let you post your average fuel mileage results per tank of gas and let those results do the talking.
Perhaps your backyard mechanic friend is like me - an old V8 person who wants that Holley 650 'dual pumper' cfm butterfly to be open all the way so she can BREATHE.
Yeah, baby. (Cut to Austin Powers...)
Or maybe he goes back to the old Stromberg '97s (again, like me).
But the 1980's brought a new tool which just about destroyed the backyard mechanic.
It was called the Oxygen Sensor.
These cars are a newer generation which use the O2 (oxygen sensor) to give feedback.
Simply put, the O2 sensor tells the
computer how rich or lean the exhaust is, and the
computer tells the
carburetor how much fuel to meter/inject into the intake.
Consider this: I play with the choke and actually succeed in getting it to open all the way.
The O2 sensor will 'sense' the leaner condition and compensate by asking the carburetor to dump more fuel into the venturi.
The carburetor dumps more fuel in with the air that I've added.
Net result?
Same as I'm now getting.
After '95, automobiles use 2 Oxygen sensors to check the exhaust before and after the catalytic converter.
These cars in theory should get better gas mileage, but after '95 they also had to put in air bags which weighed down the cars. So, your car (MK1) gets better fuel economy.
Also, there is nothing wrong with being curious.
tothehilt wrote:
Oh, the oil, i was wondering what would be the best. I am using 30 weight. My wife has a Honda Insight which takes a special 0 weight oil, so I have been wondering if I should pour something lighter than 30.
Oh, the searching was not painful at all, I enjoy sleuthing. This is a great site.
It is not my recommendation, but one thing I've learned from the other owners on this site.
They seem to recommend
5W-30. It is even better if you have no engine oil leaks and use the
full synthetic.
The more you learn about this site, the more helpful it will become.
tothehilt wrote:
Addendum: I just relayed the info about the carb to my mechanic and he says he has worked on a lot of them and never seen one where the choke plate was not vertical when the engine warmed to operating temperature. Is this the exception? Maybe the thermostat is off. We are going to warm it and then pour some boiling water on the pellet housing this afternoon to see if it will press the plate fully open.
Your mechanic is probably a very capable man.
I want to be clear: he has a lot of experience, and should be shown respect for his years of work.
It is always wise to listen to the voice of experience, and I have but little experience with these carbs.
Rather than attempting to 'fine tune' the carb between the two of you, hone your skills with a camera.
Take a few pictures, upload them to a folder dedicated specifically to your car, and then post the links to the pictures further down this thread.
As you develop your thread, and post pictures of how you've reassembled it, we'll be able to see if there is a problem with the linkage binding, or something to that effect.
Then, it will be like having a 'virtual mechanic' looking over your shoulder, checking your work.
I'm sure glacierburst and mkc1962 would LOVE to see what you've done.
Consider this before embarking on any more experiments.
If you wish to experiment with something, have a close look at your O2 sensor.
See if it is working; see if it is frozen in place.
If so, it might be due for a change.
That, more than the choke position, will affect fuel economy.
Also I read from 'glacierburst' that sight glass position has a direct effect on fuel economy.
Where is the fuel level in the sight glass?
For now, if the car is getting 45+ mpg, is peppy, the float level is half way up the sight glass, "where the choke is at warm idle" is the least of your worries.
Checking the different vacuum lines for leaks?
Priceless!
(choke pull off, secondary,idle up, A/C if equipped, distributor, second air valve, EGR - did I miss any besides the brake vacuum booster?)
Filling in your profile is a pain, but somewhat important.
The climate changes quite a bit from West to East Oregon, so we can't really give you the best advice regarding your carburetor from 'Oregon' as a location, nor give you advice taking into consideration altitude.
Sometimes we can't give you a shipping quote, etc. etc.
Don't worry; we're not going to come knocking at 2 am.
Using Portland as a benchmark, the high temperature today will only get to 56F.
That may not be the best time to test your choke.
What would it hurt to check it on a hot July afternoon?
For now, run some fuel through it.
Fill it up, drive it. Fill it up, check the fuel mileage.
Get a feel for what it can do.
Then 'tweak' it...a little at a time...to get what you want out of it.
Sound deadener, nice tunes, clean it up... you get the picture.
Welcome to Teamswift.
I look forward to further updates on your car, and wish you the best of luck with it.
Happy motoring!