guitarguy12309

well i just got my electic water pump done and my injectors cleaned and now my cars getting super bad gas mileage and like when i first got it...i do know the 160 thermo will lose you some gas mileage but not this much!!! we're talking like 90 miles a tank...my opti did get wet but was only a couple months old and still works fine from what i can see

anyone have any ideas as to why im running rich??

MentalCaseOne

I had a similar experience when I first moved to Hawaii. I had my car shipped from California. The car ran fine exept I was getting only a 100 miles per gallon... The car ran fine other wise.. My first thought was that since all my new driving involved less than 2 miles each direction I was runing the car in open loop must of the times...

Then out of a hunch I decided to buy a locked Gas Tank Cap and all of a sudden my mileage per gallon doubled!!!


This may not apply to you but in my case is a true story.

Marvin

BirchMan98z

100 miles per gallon!!! Impressive... lol

Injuneer

-faulty O2 sensors
-exhaust leak before the O2 sensors
-misfires

You could get some insight into the problem by having it scanned and looking at the long term fuel corrections. A good chance something is pushing them up unneccesarily.

MentalCaseOne

**** The car ran fine exept I was getting a 100 miles per gallon...***

Dang!!! Must've been the Hawaiian Aloha!! I crack my self up.... If someone had told me I wrote that down I would not have believed it my self...

Of course ya'll know I mean to say... 100 miles Per tank...

(feels dumb now).


Marvin

MentalCaseOne

On a more constructive note....

I know first hand that misfires will make your PCM dump more fuel on the other cylinders. It took just two bad spark plug in my case to get the other six fouled up. I had to edit this post... I had one bad spark plug and one bad spark plug wire too. or two misfiring plugs total.

And they (all eight) were Black Black. Funny thing is I did not see any black smoke come out of my tail pipes.

Marvin

guitarguy12309

thanks guys i know i only changed 1 o2 senosr because the other one was rusted in and i was gonna take it to meineke but i kind of ran out of money for it...also i could be getting misfires because my opti did get pretty wet...also when my opti was dying last time that was after a complete tune up so ill have to check to see if the plugs are fouled up at all could be though...gosh i really dont want to have to do the spark plugs again even though i got the wires in those spark plugs are a beotch to change...

i think i might take it to a shop to look for vacuum leaks too anyone have an idea of how much that would cost to get the leaks fixed??

gosh this is a lot of work to be doing god i hate maintence i spend all my money on maintaining so i cant afford to get anything good on it

LREFLYBYOU

Well if your getting misfires or if your O2's are bad your check engine light should be on...Just take it to autozone they can do a freescan of your computer for you and let you know whats going on.

guitarguy12309

no check engine lights...is it possible with obd1 for it not to flash the ses light??

oh and i tried autozone and they dont have the obd1 scanner only the obd2 one

drewSS

I would also check your fuel pressure. I have heard of a lot of people who have had problems with their fuel pressure regulators running at way to high of a pressure.

LREFLYBYOU

You should be able to hear it dropping cylinders,hold it at a constant RPM like 3,000 and try and hear it.If it is missing while at an RPM chances are your opti is ****.

guitarguy12309

well i know it surges a little when its idling might be a slight miss...the car kind of shakes now periodically which is what it was doing before when my opti was going too...i know i need to get that other o2 sensor in but its rusted in there and even the shop i took it to couldn't do it...i just hope it isn't anything major...

you guys think a vacuum leak would lose me a lot of gas mileage?

LREFLYBYOU

Vacuum leaks on LT1s are absolute killers,I know when I put a motor in my friends lt1 we had one hose with a hole in it,the car acted like it had a 900 lift cam,it was going nuts,wouldnt idle,wouldnt run,sounded like ****,fixed the hose and the damn thing ran like a top.

guitarguy12309

well guys i fixed some of my vacuum leaks and realized that when i deleted my air pump and took all the tubing off i figured from the looks of it it had a one way valve and should'n t be coming back thoguh the hole but i had my engine running while i was looking around the engine and noticed there was exhaust coming out of the hole so i capped that off and my gas mielage went up a ton and i no longer smell gas when im just idling

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LREFLYBYOU

YAY!Good job man,vacuum leaks on late model motors are KILLERS!