'95 LSS Delta 10 MPG?!!!!!

Car was rough, idling badly and shaking wildly between 50/50mpg. under or over that was fine. Mileage was nauseating, like 8 mpg around town.!!! Mechanic did tune up, and repl. 1 ignition module and PCV? valve and air filter. Runs real fine now. but........still getting only 10 mpg around town? Any body out there got any suggestions? Its never been good on gas but this is ridiculous! Oh BTW, car has pretty much blown white smoke forever as far as I remember and had a plenum replaced three years ago.
luv ya all,
joyce

Could be you have a bosch O2 sensor, these will cause similar results.


Go to GMPD and buy an OEM O2 sensor for your car.

Go to Autozone and find the OEM delco plugs


You say you had the plenum replaced, many cars that have this failure actually end up destroying the engine if the problem is not found soon enough, water/dexcool in your engine is BAD.

If you are blowing smoke there is a BIG PROBLEM. These cars are among the cleanest available from GM and the L36 motor which you have should have a 29-32MPG Highway depending on elevation/temperature and 19-23MPG city depending how much stop and go and above factors.

so if your engine is still ok I would go ahead and replace the O2 sensor too see if that helps, you see these clog up every 50,000 miles if the engine is running perfect and can clog in a week if you are running rich (O2 gets "lazy" as some call it).

http://www.gmpartsdirect.com --- get it for 45% off the dealer price or just go to the dealer and pay 75 bucks or so.

How is the WOT performance? your cat is probably clogged if you are blowing smoke. How long does it take to get from 0-75mph at high throttle?

thanks a lot, and sorry for not getting back sooner.,
probably I forgot to check box to notify me when I had a reply.
Sounds like might be 02sensor, as I never have had that replaced.
Can I ask you tho, do I need Delta wires too, as I just had a tune up.
Mechanic who replaced plenum 3 yrs ago told me I caught it very early.
Diff. mechanic who did tune up few weeks ago, said engine is in real good shape. 120K.
Sooooo, I will get the sensor through the site you sent me, and should I get the delco wires too?
thank ya
joyce

GM engines run better on OEM parts so if I were you I would spend the extra money and put on genuine DELCO parts (be sure,there are imitation parts out there).

auto trainy, hi there!
I will get those parts, the 02 sensor
but I am confused on the wires.....
what wires, plug wires? Or wires for the 02 sensor. You see I don't know what or where this thing is..... hehehehehe
I just had a tune up.
What to do?
thanx again, trainy,
Joyce

OK I will get you part numbers then

First I dont know what the tune up consisted of so I would do the cheap things first and go from there.

I am assuming you have the non-supercharged version


Spark Plug Wires:
Autolite Professional: 96197
$26.94

located at:
Advance Auto Parts #6704
478 W. Main Street Suite 1
In stock


Spark Plugs:
AC-DELCO 41-940
$5.99, you need 6 of em

located at:
Autozone
200 N COMRIE AVE
JOHNSTOWN, NY 12095
(518)762-4060
In Stock, as well as online store


02 Sensor:
GM OEM Part: 25312185
GM LIST: $75.11
GMPD PRICE: $37.56
Shipping: 7.95ish
http://www.gmpartsdirect.com



You may also have a clogged cat converter if your car seems slugish and does not "get going" when you hit the gas, and I mean that it should be up to 60mph in 7 or 8 seconds if you press the gas down.


The O2 Sensor requries a special socket available at any parts store.

You can try using a regular socket but it may be rusted on there.

The socket you buy should look like this:

http://partners.drivewerks.com/catalog/images/tools2003/KD-3259.jpg

located at back of the engine comparment on the exhaust pipe.

Please get in touch with the mechanic who performed work and see exactly what was performed and what parts were replaced, and what brands the parts were so we can narrow this problem down.

also what is this about blowing smoke???

I assume you have that emissions testing stuff out east (here in idaho they could care less if you are dumping gas/oil on the road as you drive and if your windshield is smashed)

But does the car blow smoke right now?

I would try to put a new O2 sensor in ASAP to see if that does anything, since it is a main part to make the car know how much gas to use (for how much air is comming in).

Not sure how mechanically literate you are as far as replacing that goes but basically is a little sensor that has one bolt holding it on to the exhaust downpipe at the very back of the engine bay, sorta hard to see but if you lean back there you will see it.

Has a wire attached to it and when you buy a replacement it has the wire and you just clip that in to the connector

Since the tuneup, replace PCV valve and air filter too, the car runs very smooth and fast. I havent tried to 0-75 yet tho.
The tune up parts were purchased in Advance Auto here in town its the only place we
ve got. I will check on the manufacturer of the parts Monday as you suggested and order 02 sensor.
Car was inspected a few months ago and passed exhaust test.
Do you think now that car is older I should change from regular gas to higher octane.
Have a great day Hansnet!
Joyce

THE FIRST HALF OF MY REPLY DISAPPEARED !!!!!
What I said was,
On a day like today, cool(cold) and rainy, or in the winter, or humid, it blows white smoke. I do check the radiator fluid and the level is fine. I also check the oil cap for signs of water, and that is fine too.

Well all I can really say is that the L36 motor packs a punch and if it is running well it will throw you back in the seat a little when you get on the gas. If it is not doing this, something is wrong somewhere, not that it is good to go wide open throttle on the transmission, just saying that the power should be available when needed.

I assume your coolant resivor level has not changed either since you last checked it, if any change is noticed I would get it checked out since you have the vulnerable intake design.

Other than that if the car is running smooth, I would get that O2 sensor at a dealer or thru gm parts direct web page as soon as possible, often this will cause a car to loose 40% economy if it is really lazy or old.

Not sure if you are handy with a socket wrench but get a friend/spouse/mechanic that is somewhat mechanically gifted to swap out the O2 sensor. It is one bolt and a 10 minute job if you have the correct tool listed in my previous post.


It is fine to run 85 or 87 octane gas in the natrually aspriated (non supercharged) engines since they do not require higher octane. It will not help out economy or anything of the sort, but just empty your pocket book a little quicker. Sure you could it wont do anything bad but it wont really help out either unless you have a supercharged motor, which you dont.

Please see which BRAND of spark plugs they put in your car since certain brands can damage your particular engine or have other nearly as bad adverse effects as many people who own a car with your same engine have discovered.

As far as passing emmisions testing...are you sure the car is not blowing out white steam as opposed to smoke? They may look similar.

One last question, when you had your oil changed, did they tell you how much "below" levels the oil was?

10mpg is FAR FROM NORMAL for your car unless you are sitting in traffic 95% of the time. With the price of gas these days it is important we get this problem figured out.


So in summary, get the O2 sensor replaced, find out what brand of plugs you have in now, and any other information about what was done in the tuneup more specifically.

- Hans

Hello Hans,
Thanks for being here for me I did the 0-75 in 10 sec. yesterday with no problem. Usually as I said I toddle around town and get 10 MPG NO LIE, but this week had two long trips and averaged to about 18-19.
You were right on about the 02 sensor costing 75 bucks locally. I called the GM dealer in town!
Well, unbelievably I may have a new problem. For approx. 5 days, when starting car, I was hearing a low hum. Usually radio was on so I dont really know for how long. But, I got out of car and the sound was coming from rear, under car. Proceeded to test ignition, starting and shutting off. FUel pump sounded louder. Car started every time. Once or twice after ten tries or so, I did not hear the fuel pump, only a very low click,click,click sounding electrical to me. Then, next time I tried, fuel pump sound again.
Yesterday leaving from 100 trip, car did not start when i turned key. Tried again, and finally started on 4th try.
Oh boy, what dya know, a new problem I guess. Could this be part of my mpg issue Hans?
Thank you so much for your assist. You are Awesone!
Joyce

how often does your gas tank get below a 1/4 tank?


also do you have elc (electronic suspension)???

Hi there Hansnet!
I change the oil every three months. Usually at about 1200-1500 miles I check it and its down two or three lines on the stick, takes about a half of a quart. Car has 120K.
Your question as to tank 1/4 full is a great one! Getting 10 MPH that happens at least twice a week. I usually dont gas up til its almost on "E" That's not a good thing?
Electronic suspension Im not familiar with. I have ABS and Traction.
No problem starting the car by the way.
The coolant reservoir I check often, and its always fine.
I'll be seeing my mehanic Friday. He has been out quite a lot lately, chemotherapy and only 35.

Joyce

Hi there Hansnet!
I change the oil every three months. Usually at about 1200-1500 miles I check it and its down two or three lines on the stick, takes about a half of a quart. Car has 120K.
Your question as to tank 1/4 full is a great one! Getting 10 MPH that happens at least twice a week. I usually dont gas up til its almost on "E" That's not a good thing?
Electronic suspension Im not familiar with. I have ABS and Traction.
No problem starting the car by the way.
The coolant reservoir I check often, and its always fine.
I'll be seeing my mehanic Friday. He has been out quite a lot lately, chemotherapy and only 35.

Joyce



Since the fuel pump on our cars is INSIDE THE TANK it is cooled by gas in there.

NEVER LET IT GET BELOW A 1/4 TANK OR THERE IT IS JUST WAITING TO FAIL.

This goes for a lot of cars actually.


It sounds like you should just put a new 02 sensor in and go from there.

Please get back if you find out what is causing this problem.