G. Man

Ok, So my car is running extremely lean. The mechanic said about 10x to lean. What can I do to figure this out. With the air cleaner off, I spray carb cleaner around the base of the carb and the idle speeds up. Doesn't do it anywhere else, so I'm thinking it's the carb gasket. But I was also thinking that some of the carb cleaner could be evaporating up and getting in, causing this. I want to have the carburetor rebuilt anyways, but I don't want to spend the money without knowing why it's running so lean or where this vac leak is.
Any suggestions will be appreciated.

Oh, I don't think it's a vac line causing this. I've replaced quite a few, and the others look good.

92dxbeast

Try taking the whole carb off and clean it

Gustav129

Before you do that, put the air cleaner back on and spray the base with the carb cleaner. If the idle still bumps up, then you KNOW it's the carb spacer. Last I checked (last week for a co-worker), they were like $75-$90 from Honda.

crxguy406

Another good way to test for vac leaks is to use WD-40... if the oil hits a leak, you will notice it run differently for around 20 seconds before the leak opens up again. I used this trick all the time on my spaghetti pile of nightmare vac hoses.

G. Man

First off, thanks for the reply's everyone.

I did try with the air cleaner on, but there are a couple slits on the bottom of the air cleaner where the carb cleaner gets in, and speeds up the idle. I first thought I had a gasket leak on the intake manifold, because when I sprayed around it I got the idle to increase. But then I realized there were those slits on the underside of the air cleaner (factory slits about a 1/4 inch long, not cracks or anything that's not suppose to be there).

Is there just the carb spacer there, or is there a gasket too? Or is the carb spacer a gasket lol?

stenseltizm

I had an issue with my caddy where I couldn't be 100% certain with carb cleaner.
Maybe i'm too deaf or just suck at it.

So I bought a pvc cap and a rubber coupling that were about the size of the MAF sensor.
Drilled a hole and screwed an air nipple into the cap, then capped off the MAF.

With my air compressor regulator backed off to less than 2 psi I could take my time and spray soapy water all around and located every leak visually.

It cost like $5 and should work just fine on your carb as well.

Gustav129

We just had a big discussion about this. Or maybe it was on a Mustang forum.

You don't want to be looking for a VACUUM leak by pressurizing the system.

A vacuum leak can be caused by a simple internal diagonal cut on a vacuum hose, and the hose is porous enough to leak vacuum. If you pressurize the system, that flap can be held closed and no sign of a leak present.

Gustav129

We just had a big discussion about this. Or maybe it was on a Mustang forum.

You don't want to be looking for a VACUUM leak by pressurizing the system.

A vacuum leak can be caused by a simple internal diagonal cut on a vacuum hose, and the hose is porous enough to leak vacuum. If you pressurize the system, that flap can be held closed and no sign of a leak present.

G. Man

BUMP!

letank

The vacuum system is a marvel of Rube Goldberg machinery. There is colored schematic on picasa when I tried to find my leak(s) on the EW1 engine for the 86. I stopped chasing it until it gets worse. I have another 16 months until the next smog check.

What I have noticed is the first morning start the engine will go above 3000 rpm for a 15 seconds after I drive, there is something to track. I run lean too at 1500ppm of Nox.

I played with the air filter and plugged the disconnected hoses to prevent vacuum leaks, I tried to bypass some system to isolate a possible malfunction.... I have 2 units to work on, the cold advance is non op, and the anti back fire valve.

As for carb gasket there is a gasket.

Best,