George
This is maddening, there are no codes or pending codes, the rig and engine run great, the tranny shifts at the correct RPM. No smoke, smooth idle at around 625 and great acceleration. there have been no misfires so far. there is no EGR on this motor
The engine was replaced with a crate engine that has 30k on it now. The invoice says it replaced the thermostat, a bunch of seals and a gear? No idea on the O2 sensors
I will pull the MAF tomorrow and hose it down and check the throttle plate for gas smell and see if there is any carbon on the bottom of throttle plate. no reason to suspect compression problems Do you think a replacement ECT sensor would be a wise try?

The only problem I can find is watching my fuel gauge drop steadily with in town driving almost a half a tank to go 80 miles of city driving

Thanks,
DB

 

Sorry for bothering Your conversation, but did You check the engine oil? Does it stink of an (unburned) fuel? What is Your lubrication pressure? Or what is the pressure difference in between a cold/hot engine?
Recently my engine went bye-bye. At start, it was running rich - now I can compare it to another engine I am using right now. It threw no codes till the very end, but was knocking insane loudly. However I must admit, it had a consumption of 27MPG when it died.
In general, these amounts of fuel can't magically disappear. Question is to find out where. Not into a combustion chambers for sure , as per given fuel trims.
EDIT:
Oh, I have another idea for You. Check the engine load while driving. Maybe it is getting more load than expected. You may lookup that value by a dongle using Torque Lite or Car Gauge.

 

 

Mike,
Thanks for ringing in.
Using the dashboard oil gauge, at engine start I am reading about 55 PSI at a fully hot motor I am reading a flat 40 PSI. The rig had a recent oil change, so oil is very clean and sticking the dipstick right up to my nose I smell no gas. I know man, this is making me nuts. Just recently I drove around and around a big empty parking lot and walked it to see if I could find fuel drips, nothing. I crawled under the rig while it was running to see if I could fuel dripping into the belly pans, I couldn't see or smell any. I have no drips of any kind on the concrete under the rig, just some water drips that don't smell at start up and idle The only place I get a strong hit of gas is when I remove the gas cap, then I get a strong hit of gas fumes. Screw the cap back on and it's gone.
The only knock I can hear is when the A/C clutch kicks in, and then it is a smooth sounding motor, a little loud, but smooth. The motor isn't shaking or chugging, or lifter sound or a sloshing sound that tells the even the most amateur motor head that there is something not right.
I am going to try a couple of things on Monday, if I can't figure this out I may have to pay a shop to put it on a lift to do a search and a fuel pressure test and run their scanner on it to see if they can find anything.

Thanks,
Donald

 

Without the ability to do more intense measurements, the prime candidates are:

MAF
ECT sensor
O2 sensors
Something got changed with the engine swap
Fuel leak

George

 

Just some other thoughts.

Could there be a problem with the EVAP system causing the poor fuel mileage? It did start after hooking up the broken vacuum line to it.

What about the air filter box snorkel being smashed shut where it goes through the radiator support? I mentioned this earlier. Have you checked it?

But either of these I would expect to affect the fuel trims.

 

...so did You check the load? You can look up a PCM value. How about the drivetrain significantly loads the engine? I am asking as it seems Your engine is more than perfect.

 

Mike, I don't have an Android device, so I can't use those Apps, only anIphone 8 that belongs the the woman.
I am going to clean the MAF, and swap out the ECT and air temp sensor in the air intake hose on Wednesday and see if it makes a difference. If not I guess I will need to take it to a shop. I am lucky that I am retired so I don't do a lot of driving, but still it is a killer to keep filling the tank after grocery shopping.
Plus I am wondering if I am sitting on a time bomb with my engine sucking all this gas and no apparent reason, and then have it up and die with no warning.
Thanks everyone.

Donald Bowman

 

Another thought. What is your MAP readout on a cold engine at KOEO?

George

 

George,
The outside temerature is 96 degrees.
The engine has been off for two hours when I took these readings
MAP key on engine off 97

Key on Engine on 33

That doesn't sound right does it?
Donald Bowman