10 mpg

[RonD]

Coolant has a pretty distinctive smell out the exhaust, can't miss it

180psi means not a cracked head or head gasket issue, assuming at least 2 other cylinders were tested and were near 180psi
Reason you need to test other cylinders is because while gauges are fairly reliable they are not calibrated for each use, lol
So if 2 other cylinders showed 220psi, the 180psi would be low and gauge is out of whack

Almost looks like you put in an additive with the fuel
Did you?

Could be engine is running too cool and too rich but would need to be both
Temp gauge on dash should be just below 1/2 after 5min run time in summer, 8min in winter
1/2 on Ford temp gauges is 205degF, correct operating coolant temp is 185-195degF

 

[HakunaMatata]

Coolant has a pretty distinctive smell out the exhaust, can't miss it

180psi means not a cracked head or head gasket issue, assuming at least 2 other cylinders were tested and were near 180psi
Reason you need to test other cylinders is because while gauges are fairly reliable they are not calibrated for each use, lol
So if 2 other cylinders showed 220psi, the 180psi would be low and gauge is out of whack

Almost looks like you put in an additive with the fuel
Did you?

Could be engine is running too cool and too rich but would need to be both
Temp gauge on dash should be just below 1/2 after 5min run time in summer, 8min in winter
1/2 on Ford temp gauges is 205degF, correct operating coolant temp is 185-195degF

I live in Florida, needless to say I just use water, no coolant

 

[HakunaMatata]

Coolant has a pretty distinctive smell out the exhaust, can't miss it

180psi means not a cracked head or head gasket issue, assuming at least 2 other cylinders were tested and were near 180psi
Reason you need to test other cylinders is because while gauges are fairly reliable they are not calibrated for each use, lol
So if 2 other cylinders showed 220psi, the 180psi would be low and gauge is out of whack

Almost looks like you put in an additive with the fuel
Did you?

Could be engine is running too cool and too rich but would need to be both
Temp gauge on dash should be just below 1/2 after 5min run time in summer, 8min in winter
1/2 on Ford temp gauges is 205degF, correct operating coolant temp is 185-195degF

Guage sits just below half all the time and gets hot within 5 min. Only issue I see with saying it's not a cracked head or gasket issue is that the engine is cold, could only show up when it's hot.

 

[RonD]

More likely to show up cold, before head metal expands, at least in my past experience
And yes, spark plug tips look super clean if water or coolant gets in a cylinder

Point of coolant is to prevent corrosion inside cooling system, not really related to where you live or average outside temps, anti-freeze properties are just a bonus

In any case that spark plug tip is way to dark so there is a mix issue

 

[HakunaMatata]

More likely to show up cold, before head metal expands, at least in my past experience
And yes, spark plug tips look super clean if water or coolant gets in a cylinder

Point of coolant is to prevent corrosion inside cooling system, not really related to where you live or average outside temps, anti-freeze properties are just a bonus

In any case that spark plug tip is way to dark so there is a mix issue

Well the thread started with my bad gas mileage, so mix issue is known and plugs support it.

I have changed plugs, radiator, upper and lower thermostat housing w/stock thermostat and new temp sensor, water pump, air filter, many different cooling and heater hoses, heater valve, egr, egr solenoid, and pressure differential switch. I've filled it with 50/50 premix so if it's getting into the cylinder I will be able to smell it. I will be going to my shop with a lift tomorrow and replacing collector gasket on the exhaust as well as manifold to pipe donuts, both upper 02's, fuel filter, and a oil change. I got the tool on the way that is needed to hookup seafoam to slow drip into brake booster vac line and clean out the engine. After all this is done throughout the week , i will be pulling the plugs, checking them, and probably replacing them again due to seafoam treatment. Other than that I'm still lost on mpg. Hopefully something here helps.

 

[HakunaMatata]

Ok, so put it all back together and used it today, only drove 60 miles, short day due to rain. Still used 1/4 tank on guage. It did drive a little better but had many times it bogged or was very sluggish from a dead stop till it hits 2500 rpm. Doesn't happen every time, and feels worse or does it more if I turn the engine off while I'm at the stop for 15 min then restart and drive. I tested fuel pressure, guage said 64.5, just a tad over 64 but not 65. I unplugged maf, it dies right away. Tps not that old, don't think I've ever replaced iac. I'm lost and no idea what to test next. Getting a leak down tester later this week and will test all cylinders.

 

[HakunaMatata]

Well I ran some seafoam through the booster line, I can feel a difference in the engine but it's still has the low rpm issues. It bogs but doesn't get rough, just has no go to it. It happens almost everytime I turn the engine off and it sits for more than 5 min or if it idles for more than 5 min. Stop and go, doesn't normally happen. Been told by several mechanics and friends the plugs look like it just running very rich, not water. Several have said maybe it's a leaking injector, but all plugs looked the same, I doubt all of them are leaking. I'm going to replace the iac and maf with oem ones and see if that helps at all. I also want to run some seafoam through different vac ports, probably egr port, to maybe clean out throttle body a bit, after I do that I'll change plugs and 02's. I have a professional scanner that allows me to test all sensors and perform tests on thing on the way, it will be here Monday, so I should be able to deep dive into the computer once it gets here and see what the computer says about a/f mix and injectors, along with many other things. I'll post results from all of this and what I find next week sometime.

 

[ekrampitzjr]

For some reason the voice inside my head is screaming, "vacuum leak".

 

[HakunaMatata]

For some reason the voice inside my head is screaming, "vacuum leak".

I've checked all lines, all in good shape. I Unplug maf and it dies immediately. Haven't sprayed carb cleaner around intake yet, but I will. I do get 15-17 on vac tester.

 

[HakunaMatata]

So got my scanner and I'm able to view live data. I honestly have no idea what I'm looking at or for. I see some things that I don't think should be right, so I Google them and really get no answer. Anyone have an idea of what I should look for?

 

[Blmpkn]

Check your fuel trims like Ron talked about in post #14

 

[HakunaMatata]

Check your fuel trims like Ron talked about in post #14

Well at idle in park, engine (190°) warm they are
STFT B1 = bouncing between 0 and 6
LTFT B1 = 7
STFT B2 = bouncing between 0 and 6
LTFT B2 = 2.3

Also

02S B1S1 - between .1 and .7 very occasionally under .1
02S B1S2 - between .1 and .3
02S B2S1 - between .1 and .7 very occasionally under .1
02S B2S2 - between .1 and .3

CALC LOAD = 30.6 AC on, 27.8 AC off

MAF = .5
Ambient = 81°

TPS = 21.2
Rel TPS = 0.0

BARO = 30

EVAP_VP = -3.3

 

[HakunaMatata]

All of that seems fine to me. The engine idles fine, no sputtering or misfires, really no other issues other than low fuel mileage and poor acceleration from a stop. So I did a stall test. And it seems it locks up at 2k rpm. I believe these trucks are 3k converters correct?

 

[HakunaMatata]

I let trany cool down for a bit and di the stall test again. Rpms hit 2,200, maybe 2,250. Hard to say by the guage. Either way it should be between 2,850 and 3,400 from what I can find online. So to me this is a good bet its bad. Unfortunately a good bet I'll be replacing the transmission about 6 months after changing the converter as well lol.

 

[HakunaMatata]

Well I want to give an update. I pressure washed the engine before doing these repairs. I dropped trany and replaced TC as well as filter and fluid. Also replaced motor mounts, trans mount, starter, flexplate, and both B1 02 sensors. I then took apart everything on top of motor to remove intake and injectors. Injector seals were bad and Injectors were very dirty. I cleaned everything up, replaced all seals, gaskets, and orings involved with this and put it all back together. Went ahead and replaced coil, plugs, wires, pcv valve, and maf as well. She runs like bran new and stft is now between -2 and +2 at idle.