Those of you who saw my previous thread concerning my new-to-me SA22C would remember that I was/am getting terrible gas mileage. Those who didn't, now you know. The strange part is that the car now runs great, has no backfire/exhaust pops and the timing/dwell is spot on. The carb is in perfect spec as far as I can tell visually. The floats are level 1/2 up the sight glass on both sides. The car does not hesitate, bog or act up in any way. My mileage is still terrible. What the hell could it be? I owned an '82 and it got approx 15 mpg in the city, which is about the norm. My '79 gets maybe half to 2/3rds that. I just don't get it. I mean if the carb needed work, wouldn't the car act up?

Matt
1979 SA22C

 

Could you have a fuel leak somewhere?

 

are you sure you aren't leaking? how is acceleration? your tranny and dif fluid could be old an you are encountering a lot of drivetrain drag. my sa would actually heat the drivetrain up to the point were the shifter area would be hot as hell. fluid had never been changed and looked like it was half metal.

 

my shifter gets warm also, and I have redline mt-90 in there, I think its normal.

 

Are fuel leaks common in these older cars? Whereabouts do they normally leak? If that's the case, I better get it fixed ASAP. The last thing I need is my car turning into a fast-moving fireball.

 

this is just a shot in the dark but ... maybe the carb adjustment is off a bit on the rich side?

 

The idle mixture is as lean as it goes without being rough at an idle of approx 800 rpm. The car runs fantastic and shows no sign of poor adjustment. The exhaust pops quite a bit when cold, but very rarely when warmed up, which I assume is normal.

 

Do you ever smell a "gas" smell when you're inside the car, or outside the car?

 

I park the car in a garage, and when I open the door to the garage, I briefly smell gas, but then nothing. The garage didn't smell like gas before I started parking in there. I'm thinking that if it is leaking, it must only leak when the system is pressurised. I haven't noticed a drop in levels from being parked or a noticeable gas stain on the garage floor. Is there such a thing as dye for the fuel system? That way if it is leaking, I could tell.

Matt
1979 SA22C

 

this might be a long shot but, do you drive fast? i mean constantly have your foot on it? that could be a cause i dunno jus my .02cents

 

I don't lean on it all the time...really! Actually, I owned an '82 and I leaned on it pretty hard. It still got almost 400km's per tank or approx 15mpg.

Matt
1979 SA22C

 

well ... i'd start by changing the oil in the tranny and rear, like jeremy said. also, since we're throwing out ideas, how are your tires and clutch?

also ... do you still have the original exhaust system on it?

 

[grasping at straws]
Could the brakes be binding?
[/grasping at straws]

 

Let's run down the list here:
Oil in tranny and diff, sure I'll change it. I was meaning to go to synth anyhow.
clutch: Very strong
tires: almost new, maybe 5k on them
brakes: the pedal has a lot of travel before it engages, but I chalked that up to less vaccuum assist.
exhaust: original and fairly new from the motor back, believe it or not. The exhaust manifold is still kinda shiny. (Scary! The stock exhaust costs a mint!)
Now that I think of it, there is a kinda wierd noise from the back of the car when I'm at speed. It almost sounds like wind, but it's too loud. Brake shoe drag? Wheel bearing? I don't think it's the diff, that'd sound different.

Matt
1979 SA22C