Rough idle at start-up and poor gas mileage

[Craig]

G'Day Rob,

It should be quite easy to turn.

Sorry but I don't have any photo editing software here so I'm going to have to try this with words

In your photo:

Below the slot, the bright area is the drum. This rotates up and down as it appears in the photo (around the longitudinal axis).


Applying 12 volts to the connectors (polarity doesn't matter) should rotate the drum with a brisk 'clack'.

[Alfissimo Int.]

Quote:

Originally Posted by jrreeve Just pulled the IAC to put on the new grommet, decided to re-check the IAC again. How easy should the rotary vane be able to move? Unless i'm probing the wrong thing this thing is pretty frozen. I've tried cleaning and what-not but have had no luck getting it to move. Faulty IAC confirmed? Thanks, Rob

[Alfisto Steve]

Looking a picture above please note what I wrote earlier which states you close that small opening shown by rotating vane to close that small opening not try to open that small opening more. If you manually rotate vane in opposite direction to close small opening with your finger or a none threatening tool and after a bit a whole new opening appears on the otherside.as you move vane and increase spring tension.

If you hook up Bosch connector and turn on key you can see vane move so that little opening disappears as vane rotates and the otherside of vane opens up.

It is just the opposite of what you would expect.

Rotary vane should move easiely with finger and snap back to view in picture. If not spray with some carb cleaner.

Clearer than mud, I hope so?

[BlackAlfa]

The IAC is spring loaded and the vane/drum should move easily with a little bit of force. But, do not use a hard tool through the opening in your picture because the rotary vane has a sharp edge and the metal is relatively soft. One can easily damage the sharp edge of the vane or the smooth drum surface with a tool (e.g. screwdriver) through that opening! If the sharp edge or surface is damaged, the damage might interfere or even jam the rotation. I use a small screwdriver (wooden stick even safer if you have one) through the other opening (the opening for the hose that goes to the big rubber throttle hose) to rotate the inside piece.

You can clean the IAC with carb cleaner. However, as a pre-caution, I would suggest cleaning with the two opening sides down so solvent do not get into the electrical side (in case the seal is not good). After it is dried, I would put a few drops of light weight oil in there for lubrication.

[jrreeve]

Got it...figured that out (thanks guys!)...put the new grommet on, and hooked it back up. Seems to run alright; a lot better at startup. I can still hear the stumble, likely an air leak and I still have the exhaust mess out the back. I've got a feeling I need new clips/clamps. I've have a new Wix air filter and new silicon hose set on order. I will put those on this weekend, if they get here in time.

Rob

[Craig]

Just for future reference, this is the inside of an IAC. Don't shoot me, it from a Volvo!

[jrreeve]

Aren't the IAC for the 164 and the Volvo 940's the same?

[Craig]

To be honest, I wouldn't know a Volvo 940 if it jumped out and bit me. This is off something older, I can't remember what. It might even work on a 164.

[jrreeve]

Ran the car today for the first time in a while. It's feeling pretty good, the car has no stumble at startup anymore. Very happy! I still have not recieve the silicon hoses, but hope to get them next week.

The grommet on the IAC affected the startup immediately.

On a different note, i got an Air Filter from Rock Auto: Wix 495 46902. This thing is twice as thick as the one that came out of there, and i'm having a tough time getting all the clips down. I've verified the P/N with a thread from the site and on the air filter itself.

Compatible Air Filter?

Any tricks?

Rob

[jrreeve]

Well...ran through about a half a tank of gas since last post. We've still got a problem with very rich running. i'm up to about 65 miles on half a tank...thats no good. Summary of things checked and finished to date:

1. Verified coolant temp sensor is good
2. Verified wiring at coolant temp sensor is good
3. Verified IAC is good
4. Replaced all hoses including IAC grommet.
5. Changed air filter (issues getting down back clip see above post)

Next set of ideas???....

1. Verify Fuel Pressure (Check for leaky injectors or clogged return line)
2. Verify Timing (was adjusted after coolant pump replacement)
3. Re-check compression
4. Drink lots of beer and pray that it fixes itself....

If you can't tell...I'm grasping....and other idea's??

Rob

[Alfisto Steve]

Quote:

Originally Posted by jrreeve Well...ran through about a half a tank of gas since last post. We've still got a problem with very rich running. i'm up to about 65 miles on half a tank...thats no good. Summary of things checked and finished to date: 1. Verified coolant temp sensor is good 2. Verified wiring at coolant temp sensor is good 3. Verified IAC is good 4. Replaced all hoses including IAC grommet. 5. Changed air filter (issues getting down back clip see above post) Next set of ideas???.... 1. Verify Fuel Pressure (Check for leaky injectors or clogged return line) 2. Verify Timing (was adjusted after coolant pump replacement) 3. Re-check compression 4. Drink lots of beer and pray that it fixes itself.... If you can't tell...I'm grasping....and other idea's?? Rob

[jrreeve]

Two owners previous to me. The guys before me, knew nothing about Alfa's and had it for about 5 months before the coolant pump went. Before that, the owner was in Maryland and serviced the car extensively, and kept good reciepts/records. I don't see anything in the documentation that looks like it was chipped, but i guess the only way to be sure is to pull the ECU and look at it.

[Alfisto Steve]

Did you check O2 sensor or wiring? Try it with sensor disconnected to see if that has any effect. Better or worse?

[jrreeve]

Have not checked the O2 sensors with a multimeter yet. What reading should i be getting from the sensors? Or are you saying I should just disconnect and see if it gets any better or worse?

[Alfisto Steve]

Quote:

Originally Posted by jrreeve Have not checked the O2 sensors with a multimeter yet. What reading should i be getting from the sensors? Or are you saying I should just disconnect and see if it gets any better or worse?