Hey everyone,

I'm at a loss. I have a 95 1500 all stock with an auto trans. Truck has about 112,000 miles. Ive changed plugs, wires, cap, plenum gasket, cat converter, and still have hardly any power and can barely get 10 mpg with a light foot. It does burn oil, never measured how many quarts per 1000 miles, but when I look down the intake it's oil free so I know plenum is still good.

When I say lack of power, I can barely hold 60 mpg on a flat interstate pulling a 2 horse trailer, empty. While not pulling anything, going up slight hill with OD off can barely reach 65 mph. Ive owned the truck since 39,000 miles and never remember it being this way.

My next ideas are checking for compression, someone told me it could be fuel related, but its getting plenty of fuel if I'm getting poor mileage, right? I hate to keep throwing money at it and not getting anywhere.

Thanks

 

What kind of plugs? Copper is best in our trucks, I like NGK. You didn't say anything about the O2 sensor. I would put a new NTK in it. Also get a new Mopar PCV valve. It wouldn't hurt to dump a couple cans of Seafoam in the gas tank. It could be poor quality gas, fill up somehere else next time. The 95s have 2 coolant temp sensors, one for the gauge and one for the ECM. If the one for the ECM fails and says it's cold, it will dump a lot of fuel.

 

Oh yeah , I did the O2 sensor as well. I cant remember what plugs were exactly, but I did research on here what brand was best to get. I believe it was NGK, same with the O2 sensor. I will try seafoam and PCV valve. I have replaced it in the past but that was probably 50,000 miles ago. I did one coolant sensor when I did the plenum, the one in the front on the intake manifold. How would I know if the one for the ECM is bad? Would it show on the dash that the coolant temp is cold?

 

No, as 2bit wrote the sensors for the gauge and for the ECM are separate. There's a table in the FSM, attached:

 

Ok, I'll have to look again and see which one I replaced. Quick search it show both are right near the thermostat housing. The one I need to test is the one on the drivers side of the thermostat housing?

 

What size tires?
Dragging brakes?
Clogged air filter?
How heavy is the trailer?
Towing with OD off?
Using 87?
Does the fan spin freely when warm?

There are so many things that can affect power. These little 318s are torquey but not race engines. Add bigger tires or a trailer and you can walk next to it while flooring it. Nothing you or anyone else have mentioned will instantly add power. Towing any trailer at 60 and I'm in 4th (direct) as it can't really hold 5th (OD) even on a flat.

Oh, and stock plugs are Champion RC12YC and stock sensors are NTK.

 

Stock wheels and tires, air filter good, brakes good and front wheel bearings replaced as well. Trailer is 16 foot steel frame aluminum skin. 3.55 rear end, OD off 55 mph is all the truck wanted, not pushing it hard. Nothing in trailer. Even empty though, truck struggles to get up to speed and hold it. 87 octane. I'm not sure about fan I guess. I have owned it for years and it seem like each year it just gets worse.

 

Wouldn't hurt to check EGR either.......

 

From the year of the truck and the low miles it sounds like it sits a lot. I would agree with running some injector cleaner through the tank. They may be getting gummed/varnished. If they are it may take quite a few treatments to break it up. Might check your coil too.

 

That's a heavy trailer.

Do you mean you have it floored and all it will do is 55 on a flat?