Bad mileage

[fredpettit25]

I have a 94 ranger with a 2.3 in it. It is getting about 13 mpg, it runs but not well. It is running so rich, plugs are black, It has no low end at all. It will run but the exhaust manifold get hot,Red hot i mean like glowing red. I have replaced coils, wires, plugs, air filter, I can hear the fuel pump running. Once it gets in its upper rpm range it will go down the road but eats a lot of fuel. Any help I'll take it has me baffled Thanx Fred

 

[mongo]

02 censor?

 

[Wicked_Sludge]

check for codes and perform a self test. details on how to do so in the tech library under computers.

 

[kodiak024]

plugged cat convertor

 

[slolearner]

low mileage

I have to agree on the plugged catalytic converter

 

[BlackBII]

Pull the codes like wicked said, also check your fuel pressure.

 

[fredpettit25]

When the cat is plugged wouldn't there be hardly anything coming out of the exhaust pipe. There seems to be a lot of exhaust exiting the pipe. Also it doesn't smell funny. There is no DEQ here so you guys think I should cut the thing off?

 

[fastpakr]

NO.

Is the Check Engine Light on? If it's not, are you sure the light works? It should turn on for a few seconds when you first turn the key to the run position no matter what.

 

[Bryan22]

you also might pull the vaccum line off of the fuel pressure regulator and see if there is raw fuel in the line. this would be a sign of a bad FPR and could likely cause a problem like you're experienceing. if it checks out ok, i would still try to get a guage and get a fuel pressure reading from the rail.

 

[Wicked_Sludge]

leave the cat converter alone for now.

there are litterally hundreds of things that can cause low mileage and drivability problems. if we were to sit here and list all of them it would take all day. perform a self test FIRST as it is the quickest and easiest way to narrow down any potential problems.

 

[fredpettit25]

No the check engine light is not on and it comes on when I turn the key to start the truck. I had a friend check it with a snap-on code reader and it displayed 0, none , no trouble codes at all. That has been a while though so I will hook up a jumper wire and check them again

 

[Wicked_Sludge]

if he didnt get a code 11 (all clear), then he didnt do it right

 

[dgeorge]

I had about the same problem and found out it was the crank pulley hub. With the engine running look down at the front of the engine and see if the the bottom pulley is wobbling if it is then it could be the hub cracked and wallowed out so that it is throwing the timing off.

 

[93'Stranger]

i had the exact same problem..its your catalatic converter...the best thing to do is buy new complete exhaust because cat's are almost the same price as complete exhaust...mine burnt rich as hell,poor fuel mileage, and plugs are black, it also idles rough, and without enough back pressure could burn up valves

 

[Wicked_Sludge]

it cracks me up that you guys can condem ANY component (much less a component as reliable as a cat converter) without any diagnosis at all. you have no idea if thats whats wrong. your guessing. the only way to find out whats wrong is to take steps to properly diagnose the problem. there are a thousand things it could be and the cat converter is near the bottom of the list.

IF it does turn out to be the cat converter, replacing the entire exhaust if its still in decent shape is silly when he could replace the converter with an $80 aftermarket replacement and be done with it.

FYI, a plugged cat causes excess backpressure, which is why it causes performance issues. it doesnt reduce backpressure.