Trouble shooting?

[RonJr]

Looking for some knowledgable help. I have an '83 Buick Century 3.0 and I am experiencing some engine surging both while idling and driving. And usually when the surge happens I get an electrical draw. I was thinking it might be either the throttle position sensor or fuel pump. Any thoughts or similar experience?

Thanks, Ron

 

[The_Jeff]

This thing has a carburetor, right? It'd have a mechanical fuel pump then.

What is this "electrical draw", do the headlights dim? Does anything blink out completely?

If this thing is anything like my 82 cadillac cimarron you have a maze of vacuum spaghetti. I'd start looking there for leaks.

 

[RonJr]

Yes carb'd. Lights, stereo display, panel lights...all dim and flutter...no complete loss

 

[The_Jeff]

May be a good time to pull all the battery cables and ground wires and clean everything.

It's little known but the little 5/16" bolts inside the battery cables where they attach to the battery actually come out of the rubber insulation. Do that and get some baking soda/water in all those crevices and check the cables themselves for corrosion hiding underneath the insulation.

The carb will have a mixture solenoid (and maybe an idle speed one too) that's computer controlled, but with flaky electrics going into the computer it's kind of a garbage-in garbage-out issue. That could be why it's surging-- if it were an older carb without computer it might just ignore the electrical issues.

 

[RonJr]

Thanks el... I'll try that first

 

[punisher]

Before you touch anything under the hood, pull codes. Any stored codes will be erased if you mess with the batt cables.

With a carbed CCC system, don't get hung up on an electrical fault as a root cause. The voltage fluctuation could be a symptom of the RPM fluctuation instead of an indicator of an electrical fault as a root cause. Just like any system with a carb it is subject to all the problems carbed vehicles are saddled with.

 

[mechtech2]

Could be an alternator or battery going bad.
Also could be the AC kicking on and off.