I just bought an 89 Lxi EFI and its in good shape but it idles rough and it gets worse when I turn on electrical things like the head lights or rear defroster.It runs good when going down the road and the idle rpms is about 800. the repair invoices show that the vacuum advance was replaced and the timing belt.

Any info would be appreciated
Thanks, JIM

 

Sounds like you either need a new alternator, battery might be at the end of its days, or you need to raise your idle a lil bit.

 

Try pinching off the PCV valve hose and if the idle smooths out replace the valve

 

try the cheap things first.

plugs

wires

cap/rotor

 

what do you mean idles rough? rpms go up/down or car just shakes? being how old it is try increasing the rpms to about 1000 and see if that helps it.

 

You will only raise the idle a bit to troubleshoot, not to decrease your gas milage, does it smooth out at 1000, it may need a throttle body cleaning or a motor mount or two could be broke or very weak. Has it been getting worse gradually pointing to a tune up but why does it need a tune up now, been too long since the last one or is it burning rich, what do the plugs look like gus.