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New Hard Starting Problem - QJet

666 views 2 replies 2 participants last post by  JohnTN 
#1 ·
Have a mild low compression Olds 350 with reman QJet, vintage 1981, with APT and no computer. Has been on car since 2005, 15,000 miles and always started after one pump of the accelerator (unless set for 5-6 days).

In last couple weeks, with just one or two pumps before cold start, fires, chugs a time or two and dies. Then won't fire unless I put the pedal to the floor. Then finally fires, runs rough for 5-10 seconds and puts out lots of blue/gray smoke. After 10 seconds or so smooths out and runs fine.

Today tried 3 pumps before turning key. Fired, chugged a time or two then finally reached fast idle and smoothed out. Tomorrow will try 4 pumps.

Choke is setting with first pump. But, what is possible cause of hard starting?

John
 
#2 ·
You might have a choke pulloff problem. Vaccuum should pull the choke slightly open on startup. I dont remember the setting, 1/8-3/16 i think.
Also, we have seen those lead plugs in the bottom of the carb leak. We used to epoxy them before we put the carb on.
 
#3 ·
Took the air cleaner off tonight before trying to start the car cold in order to watch the choke operation while cranking it. Discovered one of the rubber caps over a vacuum port on front of the carb was soft and deteriorating and slipped off easily. Replaced it with a new cap and asked wife to give the pedal one pump then turn the key. Started right up. And choke pull off worked correctly.

So, possibly a vacuum leak through this broken down rubber cap (isn't ethanol great additive). Could this have caused the choke pull off not to function?

Let's see how it starts tomorrow.

John
 
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