I bought this car about a year ago..It has a K&N and dynomax catback..
I always give it on time oil changes and stuff and it was tuned up about a year ago.I run fuel system cleaner every so often and im tired of the horrible mileage it has.Why is this?I get about 10-12 MPG and its a 3.1 V6!

What could be so wrong?

 

you and me both man, cept mine is a 2.8. I need to know why too, i replaced

dist. cap
rotor
plugs
wires
fuel filter
air filter
PCV filter

I dont have an o2 sensor cause its canadian

and i still get ****ty milage

 

most canadian cars have it, i'd guess because yours is an 83.

anyway, check the timing and the injectors

 

i wish i had a light and im carbed

 

Arent timing checks done with tuneups?

If so then it should be good and im pretty sure the injector are nice and clean from all bottles of cleaner I dump in my tank.

 

the timing is computer controlled, so most places don't bother, i'd get a timing gun and check it yourself, don't forget to disconect the est.

 

So if its out of whack..what do I set it too?

 

well under your hood is a sticker, it should tell you, i know for my 2.8 its 10*

 

Id do a compression and a leak down test. could be leaky rings or valve seals. dirty valve seats.........

 

my 2.8 sticker says 16

 

What exactly does that number mean?

 

how many degrees advanced timing

 

Are there any other symptoms to incorrect ignition timing other than poor fuel economy?

 

alot of things are actually linked with it

hard to start
bad fuel milage
engine stutters
lean mixture

theres probably more but thats all i can think of

 

Hmm I really dont have any of those symtoms except maybe a shuttered idle once in a while...

 

yea man, see in my situation, it stutters sometimes, and i get really bad fuel milage, and all that black **** coming out of my exhaust pipe

 

My car is in good tune and it runs at a good temp...Maybe the economy is suppose to be like that...I do have a heavy foot but 10-12 mpg is lamborghini mileage....

 

10-12 blows. I keep my V8 car parked as it only get 15-18.

 

another thing is replacing the timing chain.

Just because you run injector cleaner thru it, doesnt mean the injectors are clean. Some could be sticking open, or the CSI is leaking over night.

Part of it is also how you drive it, and is it mostly in-town, or highway, mixture, etc.

(didnt look) auto trans? Not locking up, slipping, adjusted properly.

 

[thinking about this hmmmmmmmm]

10-12 in a V6 is just horrible.
Something major has to be wrong. 50% of your fuel is being blow into the air. Your buying 2 gallons of gas to use 1. Gas cost to much. Spend some money now to save every fill up. Autozone will lend out some testing tools or do the test there. you can get the timing checked or borrow one and a compression gauge.They are very helpful. They do things free that shops just blocks away charge $50 for.

I needed to pull codes on my Moms 02 forester and a test cost $80 local, or $60 online. Autozone does it for free. No paper clip trick for OBDII systems.

 

Gumby do you know if autozone carries all the tools you would need to rebuild a 700r4? I was given a list of about $1100 worth of tools needed. Bushing driver sets, and lip seal protectors in particular.



and I get about 8 - 10 mpg...figure 150miles to a tank and I've learned to tame the heavy foot to a degree. Planning on sending the injectors to be cleaned while I'm getting the tranny rebuilt.

 

So I should be HAPPY getting 17mpg with the wife's '92 3.1L RS?

 

You would have to cal l autozone

 

All I can think to add at the moment would be to check your alignment and tire pressure also. Timing on mine is 10*. How long ago was your timing chain replaced. I guess it stretches slightly over time and can throw the timing off a tad.

If I think of anything more today that hasn't been mentioned already i'll post it.

10-12 is horrible. I've never done city only driving, but I get around 28 city,highway, and freeway combined.

 

I HAD THIS PROBLEM ON MY 90 V6 3.1
BLACK SMOKE WAS SHORTED INJECTOR PASSENGER FIREWALL
THE MULTEC INJECTORS ON THE v6
ARE KNOWN FOR SHORTS
IT HAPPENED TO ME 3 TIMES UNTIL I FOUND OUT ABOUT IT!
THEY SHOULD ALL HAVE 12 OHMS (AT LEAST 10 OHMS)
MINE READ 9 OHMS AND LATER 6 OHMS WHEN HOT.

CHECK RACETRONIX.COM FOR NEW INJECTORS

PRESTO NO MORE SMOKE
I GUESS A NEW DISTRIBUTOR WAS NOT THE PROBLEM THAT PEP BOYS CHARGED ME FOR.

YOU CAN HAVE THE CARBON CLEANED AND THE FUEL RAIL CLEANED
WITH CANISTER SOLUTIONS UNDILUTED WITH GAS
(NO CLEANER IN TANK , THE PUMP IS OFF OR DIVERTED DURING CLEANING)

WHERE?
i BOUGHT MY OWN.