6 Mpg On Stock Blazer

[Guss]

I Did A Tune Up, Oil/filter Change W/ Mobile 1 And Still Only Getting 6 Mpg Help!!

 

[BrianDamage]

stock size tires ?

 

[Guss]

31x10.5

 

[gmcjimmy90]

what year,motor, trans ,gears ,tires.

 

[sled_dog]

egg or large block of wood under the pedal. My 84 only got about 6mpg.

If carbed did you rebuild or have the carb rebuilt? Don't expect miracles, it will likely jump to a massive 10mpg if there IS something wrong.

 

[Guss]

tbi 350. 700R4, w/ 3.73 gears shold be alot beter than 6 im realy scratching my head. it doesnt miss or anything just sucks alot more gas than it should
and to the egg thing i drive it like a grandma anyway.

 

[PsychoticDeadGuy]

running way rich or is that how much gas the engine likes? also try the O2 sensor. wont help alot but maybe a little.

 

[gmcjimmy90]

try changing the fuel filter i have 165000 on my 90 gmc jimmy, and it gets about 15mpg

 

[muddybuddy]

do u have full exhuast on it? when i jus had a y pipe on, i was only gettin 4mpg. other than that i dunno what to tell you

 

[beater_k20]

check your timing, and fuel pressure. also, start driving like a normal person.

 

[JEBSR]

If non of the above works have a scanner put on it and check the coolant temp sensor. If it is telling the computer that the engine is still cold when it is warm then it will run full rich (just like a choke on a carb staying on).

 

[Guss]

would dirty/leaky injectors do the same thing?

 

[gmcjimmy90]

yes it could also have the cat checked

 

[Guss]

recently put exaust on w/ cat but did notice injectors had partial spray with some..... not quite a drip but not a fine spray also looks like the injector seals
might be leaking. do they make a rebuild kit for the throttle bodie

 

[JEBSR]

The good thing about tbi is you can turn the key on and let the fuel pump cycle and watch the injectors. If they are that bad you can see them leak down. If it is a slow leak use a pressure gauge and see if the pressure leaks down.

Yes you should be able to get a rebuild kit from any local parts store.

 

[blackblazer717]

thats funny, last fall my K-5 was having similar problems with fuel milage but turns out to be a faulty wire in the system, i bypassed the fuel pump relay completely, and now when i turn the key on the fuel pump does not cycle it stays on all the time hehehehe. i like it, i get almost 20 MPG with 38.5 swampers on it.!

LUKE

 

[HarryH3]

The throttle body repair kit will only set you back about $30-35, depending on which throttle body you have. Remove the air cleaner and look closely at the front left edge of the throttle body housing. You need that 8 digit number when you go to buy the kit, to make sure that you get the right one. GM used a LOT of different throttle bodies!

 

[Guss]

thanks guys. 20mpg on 38s wtf how is that possible

 

[Thunder]

Before you do anything check for trouble codes. Even better buy a Scanner! Like an auto X ray or something.
One of your sensors may be bad and the ECM is in limp home mode. That will usually cause a very rich condition and lousy fuel milage.
You should be getting way better than 6 MPG with TBI 700r4.
I get 18 MPG highway on 33 MTs 3.73 gears in an 89 TBI

 

[gmcjimmy90]

sorry to hijack but what if any mods do you have to get 18mpg's