Accelerator pump or Fuel pump? 1981

[iamfine2]

1981 - symptom: Slight rough idle like it is missing, but when I accelerate it is just fine, mileage and power are fine.
Can the accelertor pump be replaced without removing the carb? Or do you think it is a fuel pump?
Computer removed, regular HEI Ignition and quadrajet.
Mike

 

[wishuwerehere82]

I think neither of them are the problem.
I would look at the plugs, wires and distributor cap first, then the idle mixture adjustment on the carb. And make sure your power valve isn't sticking .
A bad accelerator pump will cause you to stumble and sputter on acceleration off idle until you back off on the throttle.
A bad fuel pump will cause you to lack power in all operating modes or simply stop the engine.
That's what I think.

 

[gmjunkie]

I think neither of them are the problem.
I would look at the plugs, wires and distributor cap first, then the idle mixture adjustment on the carb. And make sure your power valve isn't sticking .
A bad accelerator pump will cause you to stumble and sputter on acceleration off idle until you back off on the throttle.
A bad fuel pump will cause you to lack power in all operating modes or simply stop the engine.
That's what I think.

And I think he's right!!!

 

[iamfine2]

Ok,
Any tips on replacing the plugs in a 1981?
Mike

 

[wishuwerehere82]

Ok,
Any tips on replacing the plugs in a 1981?
Mike

Change them when the engine is cold.
Do the front two plugs on either side from above, and the back two from below. Use a ratchet with a straight extension on the spark plug socket, not a swivel socket.
If you replace the plug wires, do them one at a time to match the length and avoid problems.

 

[82ColEd]

Jack the car in the front with jackstands (or a lift, if you are that lucky), trying to squeeze under the side of the car get's tricky. And you cant really get properly to the plugs.

Listen to Pete: Dont use a swivel, unless you use the rubber plug inside and you can hold the socket straight when you wrench, else you'll be breaking off the plugs. Ask me how i know. :eyerole

Front plugs (esp. passenger side): From above as Pete said, once the engine is cold, stick your hands between and around the exhaust and you can feel your way to the plugs, might have to bend some piping outta the way. It's almost impossible to get to the passenger side front plugs from below.

Just did mine and it took a while. You'll learn all new vocabulary, so no kids around.


-Stefan

 

[iamfine2]

Is it really necessary to run the spark plug wires under either side of the engine?
Ia m thining for practicality and coolness at a show to have the plug wires run over the top and loom them.
Any thoughts?

 

[GerryLP]

Mike,

Wishuwerehere's suggestions are right-on...except that I could not concur nor contribute either way on the power valve for a Rochester, for I do not know how that works (in the Holley, no problem ).

As far as the wire looms, I know what a pain they are to install in the stock configuration, but I went back to the stock configuration, for I installed black Accel 300 wires (300 ohms or leass per foot), and since they are 8 -10 mm, I figure they will last a while in there. But again, you are right...they are a pain...ad...so, if you want to get a nice set of wire looms dressing the engine bay, you going have to go with the a high quality set which will allow you to trim the correct lenght for each position. The Accel 300's are about $80 dollars, but they come in different colors, and you have to assemble them with their special crimping tool which you'll have to purchase separately (about $13 bucks).

If you go with the custom look, DO SAVE THE HEAT SHIELDS AND HARDWARE. They are not so easy to find anymore.

 

[terry82]

Change them when the engine is cold.
Do the front two plugs on either side from above, and the back two from below. Use a ratchet with a straight extension on the spark plug socket, not a swivel socket.
If you replace the plug wires, do them one at a time to match the length and avoid problems.

thats the best way to change the plugs .for me my spark plug wires go over the top.i dont like going under at all .

 

[SVO]

If the car accelerates fine, I would suspect a vacuum leak or an EGR valve problem if the valve is still on the car. Check for a split vacuum line, bad carb gasket, or bad manifold gasket. If you want to quickly check the headlight vacuum harness for leaks, just disconnect and plug the vacuum source line at the manifold. Also pull a vacuum on the vacuum advance canister to see if it's diaphgram has gone bad.