10 mpg

[RonD]

Spark plug tips will tell you if its running Rich

 

[89RanBrII]

She is now getting really bad, 10 mpg, I can tell she's dumping fuel at lower rpm, she hesitates, looses power, and smells of straight gas at idle and under 2k rpm. Above 2k she's fine, can handle the extra gas.

When the rubber intank fuel intake hose on my 89 ranger went bad, it lost power, and got terrible gas mileage.
I might just be throwing mud in the water but I thought I would mention it.

 

[19Walt93]

You mentioned electric fans and a new thermostat housing, what thermostat did you use? If the engine isn't hot enough it will use more gas, not 10 mpg but more.

 

[HakunaMatata]

When the rubber intank fuel intake hose on my 89 ranger went bad, it lost power, and got terrible gas mileage.
I might just be throwing mud in the water but I thought I would mention it.

At around 100k miles the whole gas tank was replaced under warranty due to a crack. I smelled gas all the time and seen it leaking. Knowing it was done under warranty I'm sure they didn't replace any hoses. I don't smell gas unless it's running and don't see any leaks. I will drop the tank and check all hoses and connections, probably going to replace the fuel pump as well.

 

[HakunaMatata]

You mentioned electric fans and a new thermostat housing, what thermostat did you use? If the engine isn't hot enough it will use more gas, not 10 mpg but more.

Stock thermostat, 192°

 

[HakunaMatata]

Spark plug tips will tell you if its running Rich

Unfortunately it was raining from the time I got home last night until late. Didn't have a chance to pull any plugs. I will do this weekend when I replace and fix some other things.

 

[bobbywalter]

i dont agree totally. i have seen 10 degrees out on 4.0 cammers with just worn chains go down to single digits and from inside the truck not see visible black cloud.... the pipe was sooty as hell but the plugs looked ok. truck ran smooth...just shit power and clogged converters.

with cammers....
injectors... simply a bad spray pattern from mismatched caps......measurably pulled 20 hp and increased fuel consumption from 17 mpg to 9-10....on a solid engine. took 4 sets of injectors before they got good ones.


so unless you see them tested and matched it is just hoping for the best.

even this current ohv 4.0 i recently picked up goes down to 10-11 mpg under certain conditions and is running lean at the moment. i am running an egr computer and cam sensor system on a non egr non cam sensor equipped engine. in cruise conditions on 36 in tires and 410 gears with a m5od it is actually doing 18 plus mpg at 55 mph.....i am very happy with that. i can not find the other pcm and harnesses i keep around....not sure if i loaned it out or not....but it runs well enough i dont care.


my point....10 mpg is not as externally noticeable as one may think. a 2.3 otoh...

 

[RonD]

Yes, could certainly be a compression issue
After pulling/checking spark plugs you could test compression in 1 cylinder on both banks, expected is 170psi
But would need to be down to 130-140psi range if timing chains were the issue

 

[HakunaMatata]

i dont agree totally. i have seen 10 degrees out on 4.0 cammers with just worn chains go down to single digits and from inside the truck not see visible black cloud.... the pipe was sooty as hell but the plugs looked ok. truck ran smooth...just shit power and clogged converters.

with cammers....
injectors... simply a bad spray pattern from mismatched caps......measurably pulled 20 hp and increased fuel consumption from 17 mpg to 9-10....on a solid engine. took 4 sets of injectors before they got good ones.


so unless you see them tested and matched it is just hoping for the best.

even this current ohv 4.0 i recently picked up goes down to 10-11 mpg under certain conditions and is running lean at the moment. i am running an egr computer and cam sensor system on a non egr non cam sensor equipped engine. in cruise conditions on 36 in tires and 410 gears with a m5od it is actually doing 18 plus mpg at 55 mph.....i am very happy with that. i can not find the other pcm and harnesses i keep around....not sure if i loaned it out or not....but it runs well enough i dont care.


my point....10 mpg is not as externally noticeable as one may think. a 2.3 otoh...

This I totally agree with. I don't see 10mpg being noticeable by black smoke. Clogged and broken cats has been a big issue. Definitely a lot of soot. Injectors are expensive to just replace, maybe I'll look for a shop that can test them out of the truck first.

 

[HakunaMatata]

Yes, could certainly be a compression issue
After pulling/checking spark plugs you could test compression in 1 cylinder on both banks, expected is 170psi
But would need to be down to 130-140psi range if timing chains were the issue

I definitely planned on doing that. Is there a reason you said on cylinders 1 and 2? I believe 3 and 4 are easier to get too.

 

[RonD]

4.0l SOHC has a chain driven cam on top of each head, my suggestion was to test one cylinder on each side of the engine
Not #1 or #4 specifically, any two cylinders but one on each bank

 

[alwaysFlOoReD]

Have you checked the tube from the maf to the Throttle body? Perhaps there is a leak the computer thinks it's lean and is putting more fuel in.

 

[HakunaMatata]

May have discovered the problem. Looks like head gasket issue to me. I have no water in oil, but like like I have water in cylinder. Going to get a camera in there to look at the cylinder then pressure test. Cylinder 2

 

[HakunaMatata]

180psi

 

[alwaysFlOoReD]

Hmmm, if you had water in cylinder the plug would be steam cleaned. That doesn't look it to me.