Buick V6 - Help Me Troubleshoot

Ok, so my crusty but trusty Fireball 198 V6 has been running well lately, but went to drive it today and had a few new symptoms:

1. puffed a small, light cloud of blueish smoke on startup. (never again during my drive)
2. stumbled on acceleration throughout the drive (but idled and ran at 45-50mph with no issues)
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The details

• Good oil pressure
• Idles well
• Fires up after a couple pumps and about 5 secs of the starter, cold, and with no pumps and 1-2 seconds on the starter when warm.
• All-in-all a happy motor with good power...
  
• This was on a 5-10 mile drive to pick up the kids from school, go to jamba juice and go back home.
• Never stalled, never quit - brand new symptoms from a vehicle that is timed correctly, with all correct odd-fire parts.
• No engine work in the last month other than a new radiator and coolant flush, and I literally have been driving it every Friday/Saturday on 3-5mile trips to test out new tires and just cruise the neighborhood.

Definitely felt like fuel starvation, but I had a full tank of fresh fuel.

 

Oh, and the clear fuel filter shows that the mechanical pump seems to be providing enough fuel...[shrug]

 

Hello again fellow 198'er,

So when just sitting and idling and you push on the accelerator is it slow to respond? If so maybe, that is the Accelerator Pump sticking or something? Have you had a carb rebuild as i cant remember?

 

Nope, doesnt seem slow to respond at at idle. No carb rebuild for this one yet.

 

smoke on start up could be valve seals. Did it back fire when it stumbled? Ron

 

Water in the gas??

 

Nope, no backfiring

 

I mean, maybe? But she’s stored in a garage, so probably not?

driven last week and didnt notice the stumble

 

You could drain the current gas and replace with fresh, just to rule out bad fuel as a factor.

To check the accelerator pump...
Operate the engine just long enough to ensure the the carburetor float bowl is full. Turn the engine off, remove the air filter and look down the carburetor throat, manually rotate open the throttle swiftly. You should see two streams of fuel squirted out the accelerator pump orifices, one stream into each bore if a 2 bore carburetor. One orifice and one fuel stream of fuel if a single bore carburetor.

 

Stumbled on acceleration is a classic symptom of accelerator pump failing in the carb or vacuum advance failing in the distributor. I would follow advice above about checking the accelerator pump. Dry common for them to fail these days with the alcohol the fuel. Eats them up.

 

Two bore, double shot...just fired it up, filled the bowls, shut it down: nice and strong stream x2

 

As Ohiowrangler mentions, leaking valve seals will cause blue smoke on startup. With worn seals, when you shut the engine off, oil pools in the heads around the valve spring area. A bit can drain down the valve stem past worn seals and pool in the port behind the valve seat. On next startup, this oil is drawn in to the combution chamber and burned, showing the blue smoke.
If its not that bad, just live with it.
-Donny

 

got it, nope not bad, more concerned with the sputter/stutter on acceleration, honestly.

 

Your fuel system check out? Filter, pump...little strainer on the carb...

 

Thats where i’m going next. Mechanical pumps (in my experience) tend to either work or not work. That makes me think i might be getting some flow issues from the filter. Hasnt been changed since i’ve had the jeep (i know, i know, bad jeep owner, bad) so i’m going swap it out and see what happens.

i’ll also check the carb strainer, good suggestion!