Car suddenly running poorly

[jxavierf]

Here's the background. Timing advanced 4 degrees, Idles in drive at about 1000 to 1100 rpms. Noticed poor gas milage, so I dropped the advance by twisting the disty down, and then adjusted the idle speed down. Was driving on the highway cruising at about 65....suddenly the rpms drop to zero, then back up again, seconds later does it agian. I pull over and advance the disty and adjust up the idle speed......problem solved. However seems to run very sluggishly. New disty (about 3 months old). Car has trouble starting in the morning (even before this problem). I have to pump the gas and keep on the gas to get it started.....and if I let off the gas and then press gas again, the car threatens to stall. Once it warms up runs fine, but with a slight hesitation. All vac hoses are intact, float level fine. Put Seafoam in carb and gas tank....no real help. It's an 84 gl wagon 4x4 automatic. I've noticed that the fuel tank may have crud in it do to the fact that the car sat for a long time.....so I've changed the fuel filters twice and periodically use seafoam. Car was running good a month ago (apart from trouble starting).

 

Thanks for your advice.

[Ross]

Do you mean the timing is advanced a further 4 degrees from the proper setting, or that it is set at 4degBTDC?

[jxavierf]

That is correct..... at 4degBTDC? And its been like this for about 4 months running just fine.

 

thanks.........

[edrach]

Did you change the fuel filter at the fuel pump in addition to the one in the engine compartment?

[jxavierf]

yes, twice in the past 3 months

[Ross]

That is correct..... at 4degBTDC? And its been like this for about 4 months running just fine.

 

thanks.........

 

Should be at 8degBTDC. But sounds like you may have another problem - re set your timing and give it a go.

[jxavierf]

Could these symptoms be cause by a bad fuel pump? I know subi pumps should outlast the car, but still curious?

 

thanks

[subarunuts]

Most problems like this can be traced to the carb - needs to be taken down and have the float, choke, and accelerator pump serviced. Replace the upper gasket - blow out all the passages and it should be good to go. Check for vac leaks too while you are in there. Make sure the bowl vent isn't plugged, and the charcoal canister is good still.

[jxavierf]

where's the accelerator pump and charcol canister located?

 

thanks........

[beauregaardhooligan]

The charcoal canister is black and behind the driver's side headlights.

The accelerator pump is inside the carb.

First, though, I'd try spraying carb cleaner directly into the vent tubes of the carb while it's running.

Take off the air cleaner lid and look down the throat/venturi. You'll see the vent tubes going on an angle into the float bowl.

You'll have to keep the rpms up while doing this.

[jxavierf]

I've tried the carb cleaner....and Seafoam.....no significant help. How would I test the fuel pump to see if its running properly?