OK, I have a qjet for my 71 Cutlass Supreme. It is working well with two issues. One is the standard bogging and I am not yet concerned about that. The one I am concerned with is a power hole that is erratic and happens regularly but cannot be anticipated. When going down the road under partial throttle (cruising) the engine will lose all power for about a tenth to a quarter of a second and go again. So it is a complete power loss for these small durations. It can happen once ever so often of somewhat regularly. The float appears to be properly adjusted and is letting enough fuel into the accelerator pump but I am now lost. The engine idles and runs smoothly otherwise with the exception of the WOT bogging (I will attack later as I RARELY go WOT) and this issue. I have the Doug Roe Rochester Carbs book which lists this as one of the low float problems but it appears properly adjusted. Thoughts guys?

 

Sure it's not electrical?

- Eric

 

Ditto Eric. Standard bogging?

 

Wasn't gonna go there...

- Eric

 

Not standard bogging, strictly a cutout, there is a difference. It is not electrical, all of that has been verified. It is fuel delivery. It didn't do it until the carburetor was adjusted this week. Now that it is working so much better this problem popped up. I am going to replace the 2' of old fuel line to the fuel pump in case it is collapsing. Also going to check for any possible vacuum leaks or carb leaks.

 

X2-MDchanic. I've spent most of 2 summers chasing a failing aftermarket tach that gave a short duration electrical cutout with no rhyme or reason, solved by cutting all 3 wires to the tach. I don't think fuel delivery could cause an intermittent, short duration, "miss".

Sorry, any word I selected for miss would take the topic the wrong way. I think that is what you meant.

 

HMMMMM thinking about it, new points were just put in at the garage since it was in for other work. It is possible I suppose that they messed something up in the distributor, I will look into that tomorrow. I need to get a timing gun and work on that anyway since I realized today I was using manifold vacuum for the timing advance.

 

Consider a bit of insulation rubbed off of the wire inside the distributor occasionally touching ground.

- Eric

 

That may not be an issue. Some folks like manifold vacuum, others like ported. Just depends upon which one your engine responds better to.

 

That perfectly describes an electrical problem in the ignition.

 

Ya, OK so I was wrong. LOL When the points were replaced the coil wire was too close to the side of the distributor and when I moved it the stalling was eliminated.

 

I have heard that "90% of all carb problems are in the ignition system"

Further evidence.

 

If that fixes it, great. In the event that it starts again, replace that wire. Sometimes the wire strands inside the insulation break. This can cause shutting off. Moving the wire, or wiggling it can allow the strands to make better contact and work for a while. Ask me how I know.

 

Glad you got it fixed.

As mentioned, that wire's either got a break or a bare spot - I'd replace it now, instead of later in the rain on the side of the road.

- Eric

 

It was the blade turned close to the side. I loosened the screw, turned it and problem gone.