Started new thread continued from:

https://www.ford-trucks.com/forums/1...then-dies.html

OK heres is where I'm at now with 600 miles on engine, @ idle the STFT and LTFT stay arount 0 +/- 3 but at highway speeds 2.5k rpm @ 60 mph STFT is around 0 +/- 5% but LTFT is around 10 +/- 5%, engine sounds ok power is there have new 02 sensors installed also noticed MPG (16.5) is down from original engine about 3 MPG less . No codes.

Thanks

Ed

2005 Ranger 4.0

 

Have a read here http://www.aa1car.com/library/fuel_trim_wellsmfg.pdf about fuel trim & if you don't have any set or pending trouble codes, at the articles end is a suspect list. Let us know what you find.

 

Thanks for the article, I also noticed the engine load is high at idle its 20% plus at highway speeds its around 60 -70% give it a little gas and it burries to almost 100% quickly thought that strange.


Ed

 

What are the MAF & O2 sensors doing & what does the TPS sensor reading look like through out its range from the closed, to wide open throttle position? Is the speed sensor functional?

 

Logged Forscan data attached I noticed the TP rate was strange.

Let me know what u think


ThanX

Ed

 

I can't open the file for some reason, but if you've spotted, or suspect something isn't right, hook up your Analog multimeter on the 1K ohms scale & measure the TPS resistance across the full range of travel, while looking for any drop outs, or unsteady regions. Resistance changes should be smooth.

 

How does the MAF sensor response & O2 sensor switching range & speed look??? Any notable difference between fuel injector squirt time between cyl banks 1 & 2???