Gas / mile range to low

**Pospi** · 04-08-2009, 11:53 PM

Hi my problem is that my range on tankful is only 100 - 110 miles

. That means 60L for around 170 km. I did some guick checks by freescan and I found only error code 11. Mass air sensor sending right values. I thing that problem is in rich fuel mixture becauce plugs are black on top (inside engine) So my qvestion is what can by bad? Car goes good .). If it help I can post here full log from freescan.

PS: 95er Z28 auto trans. my nods are: SLP headers and magnaflow exhaust. K&N intake.

Tnx for yours help

**JaycenK** · 04-16-2009, 09:42 PM

What dose that code mean?
How much do you have your foot in it?
do you have cats on the car?
Are all of the plugs the same? have you pulled every plug?
If you have headers and something changes the first thing you should do is check all the wires to the plugs and the O2 sensors to make shure none of the wires are burned up. Check them all the way even if it means pulling them off the plug. Best way to check for bad plug wires or cracked plug insulators is at night with no lights on either on the car or house, street what not. just look for small sparks.

**Pospi** · 04-17-2009, 12:53 AM

Ok. tnx for tips. I just order NGK iridium plugs, NGK O2 senzors and MSD 8,5 wires on Ebay. I also bought fuel presure gauge from hypertech to be able check fuel presure regulator.

**JaycenK** · 04-17-2009, 05:54 PM

ok but do you have Cats?
custom tune?
Changing the O2's may fix it but if it dosen't you will foul them out if you have a lot of carbon comming from that motor. I would change the plugs and wires like you plan to and inspect those wires as well as the O2 wires but don't change those O2's unless you find a smoking gun.

**JaycenK** · 04-17-2009, 06:01 PM

Run the car on those plugs for 30 min and pull a plug and see if it is dirty. If not run it for a day and pull it. If it is still not dirty run it for a week and check it again. If it is still clean change the O2's and watch it for a week and see if there is any change in eco.
Do you have any Check Engine lights?

**Pospi** · 04-18-2009, 01:39 AM

Yes I have cats
Here is my replaced stock Ypipe for SLP with some performance cat

This is how the plugs look like.

..and here

all gods are shipped by sellers so now I must wait 10-14 days for delivery :-)

**Too Fast** · 04-18-2009, 02:53 AM

With your O2 volts showing rich, and your Rich/Lean counter not showing any cross counts and those black spark plugs, looks definitely like it is too much gas (running rich). An easy thing to check is your fuel pressure regulator. With you engine running, pull off the vacuum line going to the regulator. If gas comes out of the regulator, even just a little, then the regulator is bad. Should be no gas on the vacuum line side.

Good Luck!

**Pospi** · 05-04-2009, 04:50 AM

so packages from us ebay arrived last week . My fuel pressure is only 34 (should be 41-43) 650 rpm

**Too Fast** · 05-06-2009, 02:47 AM

That fuel pressure spec is with the vacuum line disconnected. Is that how you checked it? The pressure will be about 6 psi lower with it connected.

**Red on Red WS6** · 05-06-2009, 05:41 PM

Never used Free scan on OBD1 but I have seen MAF sensors get blown fuses from header installs. Check your fuses and power to the MAF before you go buying anything. Get rid of all those fancy high dollar spark plugs and just put in copper plugs.

**Armani Camaro** · 05-21-2009, 03:34 PM

Look my Camaro is V6 ok and i do like 7 mile per 1 gal ok i change everythink i did tune up new fuel fillter new K&N air filter new Cables New spark plags oxygen sensors that engine is in perfect condition and i still dont know why it takes soooo much gasoline after that i found that my foot is too heavy

) thats why now im just about swap the engine for v8 ls1

) my dad is a mechanic and his sick about camaro like me he help me to do evrything on my babe

) good look man with your ride hope u gonna found out whats wrong peace !

**Red on Red WS6** · 05-21-2009, 10:10 PM

Originally Posted by Armani Camaro

Look my Camaro is V6 ok and i do like 7 mile per 1 gal ok i change everythink i did tune up new fuel fillter new K&N air filter new Cables New spark plags oxygen sensors that engine is in perfect condition and i still dont know why it takes soooo much gasoline after that i found that my foot is too heavy

) thats why now im just about swap the engine for v8 ls1

) my dad is a mechanic and his sick about camaro like me he help me to do evrything on my babe

) good look man with your ride hope u gonna found out whats wrong peace !

Even with a heavy foot a V6 should get a hell of alot better than 7mpg. You need to have it Data logged and see what the computer is doing for fueling. Is your dad a mechanic at a shop? If so have him hook it up to diagnostic machine. Do you have an SES light?