Car Stalls when put into gear

[Travis71280]

Hi everyone, I'm finally able to drive my car around town now that I've been able to fix the fuel system. Anyways my car is an automatic and when you put the car in gear it will stall out unless you give it some gas. How do you go about adjusting the idle mixture to keep it from stalling? Do you have someone put the car in drive and depress the brake while adjusting the mixture using the idle air screw? If so what RPM should I shoot for with it idling in drive? Thanks again.

Travis

[mdsalemi]

Travis, a couple of things to check: first, in P or N, how is your idle?  Should be at least 750;
Now, do you have the idle speed solenoid and is THAT working?  That's supposed to give it a bit of gas to prevent what you describe.

You might need a bit higher than 750 in P or N, and the solenoild is supposed to keep it close to that.  A lot of cars have them non-working or disconnected.

[wwheeler]

Michael is right about the solenoid. Mine wasn't working and the PO had it cranked out to serve as the permanent idle stop whether in gear or not. In addition to the solenoid not working, I had one pressure switch that was out as well.

From what I understand, one wire on the solenoid is provided a constant 12V from the fuse box, while the other is a gets it's ground from the transmission pressure switches. You should have two switches on either side, one for reverse and one for drive. When trans is in reverse or drive, these switches ground and provide the ground to the solenoid. Does the stalling occur in both drive AND reverse. If just one, could be the switches.

A/c can also activate the solenoid but since I don't have that, I am not as familiar with that function. I hope that helps.

[Travis71280]

Currently I have the idle set at 1100rpm cold and when it warms up it will idle around 850-900rpm. The idle is a little on the rich side, but that's because I haven't adjusted the idle mixture screw on the injection pump yet. As for the idle speed solenoid this is where I'm a little confused. My car had factory AC so the idle speed solenoid only kicked in when the AC came on. Just for now until I have time to fix the AC, I took the factory AC system out and rewired it as wwheeler describes. Worked well but I thought the vacuum Idle Governor was suppose to do this instead?  If so how would you adjust it then? For now though I can just hook the solenoid back in like you all described. Thanks again for all the advice.

[wwheeler]

Travis,

I didn't notice that you had a '71. I am not as familiar with those set ups because they do have the govenor and mine does not. Does your transmission have the pressure switches on the side?

[Travis71280]

It does have the pressure switches on the transmission. I just went ahead and connected the solenoid (since I currently took the AC unit out of it) ground to one side and the power to a constant 12V source on the fuse box. It works fine, but haven't been able to use it because of fuel mixture issues with the FI pump and broke a throttle linkage (adjustment nut froze up). I was just curious to figure out how to get the governor was suppose to be set up.

[ja17]

Hello Travis,

The vacuum governor should move the linkage enough to keep the idle constant when the car is put in gear. Engine idle in  or out of gear will be close to the same  rpm if it is working correctly.

Naturally, since the governor works off of engine vacuum, the engine ignition timing and general tuning must be correct for the device to work correctly. Things like bad compression in one or more cylinders, fouled spark plug or plugs will also affect engine vacuum drastically.

When equipped with a vacuum governor (dash pot), the engine should also be equipped with the "slip joint" type linkage rod between the venturi and cross over rod. The push rod coming out of the governor can be adjusted in or out to change idle. The push rod should not contact the venturi linkage at all when the engine is at idle and not in gear.

A well tuned engine will usually idle without stalling even if the vacuum governor or the idle solenoid are not functioning. In these cases the idle would fall off when the engine is put into gear but the engine will still run.