Help only 18 mpg!!! whats wrong!

[Liltucker]

i have an 88 LX 5 spd manual. so everything was cool... but now im only getting 18 miles too the gallon! its killing me!! i have no idea what could be causing this..

[monkeyracing]

The first suspect would be a vacuum leak. Is the engine idling any differently than it used to? If it's idling high, then there's a good chance of a vacuum leak.

Jim

[scitzz]

How is it running? Does it miss, stutter, etc?

[Liltucker]

ok it's been idling fine. it was haveing some problems but we cleaned the carb and it went away.. and it kinda stutters when i go from a stop but thats if im not putting on the gas hard enough. but performance wise its been fine. thats why im confused.

[perucho]

I would suspect that your catalitic converter is shot. Also when was the last time that you did a full tune-up on the car? Wouldn't hurt to replace the O2 sensor while you are at it. The only expensive part is going to be the cat. Mine was doing the same and the exhaust smell was fairly strong. Replaced the cat and no more hesitation or unpleasant exhaust smells.

[Liltucker]

i just replaced the cat about a week ago....

[Pu241]

I would suspect that your catalitic converter is shot. Also when was the last time that you did a full tune-up on the car? Wouldn't hurt to replace the O2 sensor while you are at it. The only expensive part is going to be the cat. Mine was doing the same and the exhaust smell was fairly strong. Replaced the cat and no more hesitation or unpleasant exhaust smells.

perucho,
So you were getting 18 mpg? :?
Its a long stretch from hesitation to 18mpg is equal to replace cat converter.
Diagnose first, then replace parts!

Liltucker,
Is it possible you have fuel leak or that the fuel pump is dumping fuel into the crankcase?
Check the dip stick and see if it smells of gasoline and maybe pull the plugs. If you are burning that much fuel your plugs have got to be black indicating rich running.

[25Horseplay]

The carb may also need a rebuild.

[perucho]

perucho,
So you were getting 18 mpg? :?
Its a long stretch from hesitation to 18mpg is equal to replace cat converter.
Diagnose first, then replace parts!

No I was getting about 32 and now back to 40-something. I agree with you though, diagnose first. I was just commenting on the cat as a possible cause for the hesitation he is experiencing. 18mpg is extreme for these little cars. Good luck.

[Liltucker]

no i replaced the cat so i could pass deq and get my tags etc. it could be my pluggs ill check those and get back too you guys.. but i also think theres a leak cause the side smells like gas really bad and back behind the panels on the driver side there is a smell hose that isn't connected too anything and i assume it is. but theres nothing for it too fit onto.

[Liltucker]

yea it's gotta be a leak.... cause the smell of gas in my car is over powering.... so how do i figure out where??

[FestYboy]

have a shop smoke your system... any leay will show up really quick.

[packrat427]

I agree on the leak .
18 mpg , it would have to smoke like a freight train running that rich .

It would be more than plugs to cause that also .

[Dave G]

How about a leak in the tank/fuel lines, etc? Does it smell like gas when the thing has been sitting for a while?

[jglutz]

I would suspect that your catalitic converter is shot. Also when was the last time that you did a full tune-up on the car? Wouldn't hurt to replace the O2 sensor while you are at it. The only expensive part is going to be the cat. Mine was doing the same and the exhaust smell was fairly strong. Replaced the cat and no more hesitation or unpleasant exhaust smells.

The cat fails two ways
1) it's blocked, car idles well and might drive well but no power under load, going up a hill...no power
2) It leaks...car will run better...louder...but better.