I bought a 1987 Chevrolet S10 Blazer with a V6 2.8L and 4WD last July. Ever since, I have gotten real bad gas mileage, my tank is around 20 gallons and I get less than 200 miles on a tank. According to the new revised EPA estimates, I should be getting 15 city and 19 highway. Does anybody know what could cause such poor mileage? The only thing that I can think of is that when it is idling, in park or neutral, the engine races, it sounds like an airplane is about to take off. In general, the car is always very loud, much louder than I would expect a V6 2.8L to sound. Could it be that the previous owner had done something to make it this loud that would have caused it to burn much more gas? If so, how could I fix it back to normal?

In addition, when it is low on gas (usually after 180 miles) but not completely out, it starts stalling whenever I stop at a stop sign or even sometimes when I slow down to turn. This isn't much of an issue, as I just don't let it get that low, but I'm wondering if there's anything that can be done about that, or if my problems are related somehow.

Thank you for any help.

 

Throttle body fuel injection, right?

Take off the air cleaner, and check for binding in the throttle linkage. IF that is ok, start the engine, and spray carb cleaner around, avoiding spraying it down the throttle bores. What you are looking for, is spraying stuff at gasket surfaces, and see if engine speed changes. They are notorious for throttle body gaskets to blow out, and, to a lesser extent, intake gaskets.

If you don't find anything there, pull the pcv valve out, and put your thumb over the hole, hold it for about 10 seconds, and release, should build a little pressure inside the motor, if it tries to suck your thumb in, you have an internal gasket leak.

If you have a scan tool available, check and see what the ECM Temp sensor thinks the coolant temp is, if it tells you it is -40 degrees..... time for a new sensor. Also, if it is off by more than about 10 degrees, on a cold motor, replace it. Keep in mind, there are TWO temp sensors, one for the gauge/idiot light, and one for the ecm. Make sure you change the right one.....

Are you getting any codes? SES light on?

 

Sounds almost like there is a vacuum leak somewhere causing the high idle...

 

mine does this also, i always thought it was due to fuel sloshing away from the pickup when stopping and the low RPM's not demanding enough of what fuel is left to keep the truck running

 

yeah, it sounds like a intake or tbi gasket leak or you got alot of broken vaccumm hoses/faulty connections


and as far as the stalling at 180 miles or so thats because you are very low on gas... thats exactly how my truck acts when coming to a stop or taking a sharp turn at speed when low on gas... basically its warning you get to a gas station NOW!!! hahaha


good luck