Good afternoon all, on here once again to bug you about miscellaneous maintenance problems. The engine starts and idles fine...until you put it in gear. Then it stalls shortly thereafter. However, if you start it, let it warm up - then it is good to go. I thought this was an EGR valve or choke issue until I looked up online and it could also be a transmission issue...Would like your input to get me in the right direction. And if anyone is selling a compatible 6-speed transmission.

The details:
1978 SA L-48 at the tail end of a complete tune-up (fluid changes, spark plugs, dist cap, rotor, hoses, filters, etc.)


Out of the ordinary:
The Fuel Vapor cannister is currently off awaiting some other parts to be delivered.

Car used to be hard to start, replaced fuel pump and its good to go.

Tried adjusting the choke as it would not fully close, it now does. (I think this may be part of the prob, maybe have to cut choke back a little).

The EGR valve has no give and is believed to be locked in position. New EGR valve on order. (thought this to be the cause of my problem)

The turn signals on the car do not work on startup. After warmup, the turn signals work fine.

Driving the car one day, I pulled onto an on-ramp and gave it a good shot of gas. She was good through the RPM range (4500 or so) until 120 km/h when the back-end didn't sound good. Since I only did the rear diff fluid the day before, checked to see if there were leaks (I have a habit of under tightening) and there were. So I cranked it this time, no leaks. Not sure if it's rear diff or trans yet, haven't driven the car under the same conditions since. Normal driving she sounds/feels perfectly fine.

Summary:

So that's the problems I currently have/faced. I listed them all as giving the whole picture usually helps people who have an idea of what's going on.

 

Do you have the factory manual or similar manual and check whether you correctly adjusted the choke and the fast idle screw? Did you check if the choke pulloff is working and correctly adjusted?

 

I have the owner's manual and the AIM is in the mail. Also have Haynes, Clymer and Clives Q-Jet books.

The choke pull-off was something else that came up in my searches this morning. I didn't do anything to it, and this problem is new.

I will have to take a look at it all the same, just to confirm.

The fast idle and curb idle speeds are fairly spot on at 1600 and 650 respectively.

 

The pulloff has a rubber diaphragm which can leak over the years.

 

Did the problem start when you adjusted the choke? It sounds like the idle is set fine and you have enough choke to start the motor.

I would have a helper inside the car start and put it in gear and hold the brake while you are adjusting the choke. Unscrew the 3 screws on the housing and adjust the choke till it idles in gear. If it is an electric choke you may unplug it while you are adjusting. Then, the next day after it cools overnight, try to start it and see if the setting works for start as well as idle in gear.

Cant hurt to try.

 

Update to offer some closure on this. I readjusted the choke (the coil was set 'backwards') and reattached the fuel vapor canister with all new hoses.

The engine now starts and maintains idle, even after putting it in gear.

However, the engine is now hard to start. This is a problem I had before and it was due to a failing fuel pump. I since replaced the fuel pump and at first it seemed to be working perfectly...now...it's almost as bad as it was with the old one.

The next fix is to insert a fuel inlet valve - but I am hesitant to alter the fuel line as anything I alter tends to go wrong, :p

But that is another thread...

 

You dont need a fuel inlet valve, buy the correct fuel filter with the built in one way valve which fits in the carburetor inlet. NAPA part# 23051 for the short filter or 23052 for the long filter

 

Good advice.

 

Fuel Filter

This is the one I am using, you say it's wrong?