Poor Mileage!
#1
Poor Mileage!
So before I ask anything I'll state a few things.
1998 Chevy Blazer
4x4
4.3L Vortec
Automatic
I've recently installed fresh spark plugs and wires with a new cap and rotor. The air filter is clean. There are no check engine lights. I do not have a cat but I'm running a spacer on the O2 so it won't throw a code. There are no fuel leaks or odors.
Now my problem. Despite what my on board computer says, I'm getting poor mileage. I'm at somewhere between 12-13 mpg city/hwy. My computer says 19.2, but that's a bit off. So is this mileage typical for this vehicle? I understand I will get worse mileage than a truck because the Blazer weighs a bit more, and the 4x4 probably drags it down.
BUT REALLY? I don't romp on it or anything like that. I've seen others get similar mileage. Can I assume my motor is just getting tired- or is there some secret to it all?
1998 Chevy Blazer
4x4
4.3L Vortec
Automatic
I've recently installed fresh spark plugs and wires with a new cap and rotor. The air filter is clean. There are no check engine lights. I do not have a cat but I'm running a spacer on the O2 so it won't throw a code. There are no fuel leaks or odors.
Now my problem. Despite what my on board computer says, I'm getting poor mileage. I'm at somewhere between 12-13 mpg city/hwy. My computer says 19.2, but that's a bit off. So is this mileage typical for this vehicle? I understand I will get worse mileage than a truck because the Blazer weighs a bit more, and the 4x4 probably drags it down.
BUT REALLY? I don't romp on it or anything like that. I've seen others get similar mileage. Can I assume my motor is just getting tired- or is there some secret to it all?
#2
.
So before I ask anything I'll state a few things.
1998 Chevy Blazer
4x4
4.3L Vortec
Automatic
I've recently installed fresh spark plugs and wires with a new cap and rotor. The air filter is clean. There are no check engine lights. I do not have a cat but I'm running a spacer on the O2 so it won't throw a code. There are no fuel leaks or odors.
Now my problem. Despite what my on board computer says, I'm getting poor mileage. I'm at somewhere between 12-13 mpg city/hwy. My computer says 19.2, but that's a bit off. So is this mileage typical for this vehicle? I understand I will get worse mileage than a truck because the Blazer weighs a bit more, and the 4x4 probably drags it down.
BUT REALLY? I don't romp on it or anything like that. I've seen others get similar mileage. Can I assume my motor is just getting tired- or is there some secret to it all?
1998 Chevy Blazer
4x4
4.3L Vortec
Automatic
I've recently installed fresh spark plugs and wires with a new cap and rotor. The air filter is clean. There are no check engine lights. I do not have a cat but I'm running a spacer on the O2 so it won't throw a code. There are no fuel leaks or odors.
Now my problem. Despite what my on board computer says, I'm getting poor mileage. I'm at somewhere between 12-13 mpg city/hwy. My computer says 19.2, but that's a bit off. So is this mileage typical for this vehicle? I understand I will get worse mileage than a truck because the Blazer weighs a bit more, and the 4x4 probably drags it down.
BUT REALLY? I don't romp on it or anything like that. I've seen others get similar mileage. Can I assume my motor is just getting tired- or is there some secret to it all?
I know a lot of people who have gotten worse gas mileage after they went catless. Despite what you've done to the 02 sensor, I would say the 02 sensor is your problem at first guess. It sounds like more fuel is being dumped in causing worse gas mileage even though the CEL isn't on for the 02 sensor. Also what kind of spark plugs are you running? That could be a mpg problem as well.
Here's a thread you might want to read: THREAD
#3
I'm running 235/75/15 tires. Not very big at all, tire pressure good and such. I'm running NGK plugs. Gapped accordingly and such.. I couldn't tell you specifics on them.
I assumed since it was not giving a reading to the O2 that the cat wasn't working, it wouldn't dump fuel. There are a lot of mixed answers on the topic, and I've never heard of anyone else using a spacer to fool the computer. My buddy have me one that they were using when the cat went bad, but I'm not sure if it makes a difference for mpg. I suppose I could throw a new cat on because its really the only thing that's not stock/factory spec anymore.
I assumed since it was not giving a reading to the O2 that the cat wasn't working, it wouldn't dump fuel. There are a lot of mixed answers on the topic, and I've never heard of anyone else using a spacer to fool the computer. My buddy have me one that they were using when the cat went bad, but I'm not sure if it makes a difference for mpg. I suppose I could throw a new cat on because its really the only thing that's not stock/factory spec anymore.
#5
CSFI gap is supposed to be .060. (CSFI is 96'+)
Last edited by 97cherryblazer; 10-18-2012 at 11:00 PM.
#7
I took it to a friends shop and he put his scan tool on it. There was nothing out of the ordinary according to the tool.
From what I've read and what I was told- the cat seems unlikely without a code.
The map sensor was in question from my research. I don't think that's the problem, but it's super easy to test- so I will give it a shot when I'm free.
My fuel pressure primes to 60psi and holds at 55psi or so when running. I was under the impression that a leaking injector/ regulator would create fuel odors. Am I wrong here?
From what I've read and what I was told- the cat seems unlikely without a code.
The map sensor was in question from my research. I don't think that's the problem, but it's super easy to test- so I will give it a shot when I'm free.
My fuel pressure primes to 60psi and holds at 55psi or so when running. I was under the impression that a leaking injector/ regulator would create fuel odors. Am I wrong here?