i bought a 78 camaro v8 350 with a rebuilt engine a few weeks ago that was sitting in a driveway for about 8 months, they would start it every few weeks or days(i dunno) to keep it going. i payed 500 dollars for the car and after putting several new parts in it runs great.. well the whole deal is.. its a 21 gallon tank and only gets maybe around 10 miles to the gallon or possibly less.. with a v8 id expect 12-15, what can i do to get the gas mileage up.. suggestions?

steve

 

I would do the normal tune-up, plugs, air filter, FUEL filter, wires, timing. Even though it is said to be rebuilt, I have peace of mind after that. What carb is it using? If all those things check out, maybe it has some crazy gears (4.11 or higher). Also, sometimes the brand of gas makes a HUGE difference. Good Luck

BamaZ28

 

Does it still have the original Q-jet or has it been replaced with a Holley? Chances are the carb is the problem anyway. Might be time to invest in a rebuild kit after doing the tune-up suggested above.

 

I have a 350 rebuilt in my 80.. with a 750 edelbrock i get about 8 mpg

So dont feel bad.

 

well...its my friends car. he bought the car, it seems to be running fine. i really dont know much about it as of right now. soon i shall take a look at it. im pretty sure the basic tune up might help, because last time i took a glance at the air filter it was pretty dirty. after the tune up, if that doesnt help it, we shall check the carb.

by the way, anyone have any tips on how to change the driverside plugs? on the 78 and also on my 93 z28. ive been told to take off the driver side tire, and pull the plastic wheel well away and they should be exposed right their. anyone have any other tips? for the 78 as well.
thanks

steve

 

A couple of things to check: first, if it has a Qjet, check for leaking well plugs. These are pressed in by the factory in the bottom of the main body casting to cover some drilled access holes. Over time they can come loose and leak. To check: with engine warm, idling, turn in the idle feed screws. Engine should die at some point. If it keeps running with screws turned all the way in, carb has internal fuel leak from plugs. Fix is to cover plugs with JB Weld or aluminum epoxy. Rarely it is caused by a bad casting.

Second thing: I notice you are in CA. When I was stationed out there in the early 80's, I remember you had to disable the vacuum advance to the distributor for emissions purposes. After the test, you would pull over around the corner and hook it back up. If the 78's stayed disconnected, you will lose mpg. Replacement distributors sold out there have a vacuum cannister that gives no vacuum advance. Of course, vacuum cannister can be ruptured.

 

While NOx kits were required in the early 80's, they no longer are and I've never heard of non-operating cannisters.

 

When I bought my RS out there, it had an aftermarket dual point distributor w/no vacuum advance. So I bought a rebuilt stock type distributor at local parts store. I set base timing, but when I hooked up vacuum advance, idle didn't speed up as you would expect. Timing gun showed no added advance. I thought I'd been sold a defective unit, but guy at parts store told me that is how they were sold out there - emissions. My solution: purchase of an adjustable advance cannister at Santa Ana Speed. I had to sign a paper affirming it was for "off road use".

These days perhaps that idiocy is no longer employed (can you imagine all the gas that was wasted?), but it's a 78, so who knows what may have been installed during it's lifetime.