Ideas on this one...

[Black Sun 5.0]

My car is too odd. I've had bad gas mileage (by my standards), and have had a few posts on this issue. It's gotten weirder. My car had gone from 27 MPG highway down to 14 MPG, regardless of where or how I drove. Thing was running real rich. I also had an issue with fluctuating readings on my volt gauge, it would dip kind of low for the most part, even though there was a new battery and alt. I messed around with some of the wiring, including by the battery and the starter solenoid. The volt gauge was up more consitently, and my gas mileage bumped up to 17 MPG, a little lower if I stomped now, but the way it should probably run. I brought the car to the shop, had the ECT, the t-stat (went back to stock), and the O2's replaced. We also discovered that a bad ground was causing the volt fluctuations. Now I'm back down to 14 MPG and running rich again. What the heck is up with this thing?

 

[mike93lx]

you mentioned twice that its running rich, but you haven't said anything about trying to adjust the fuel pressure. i would definitely get an adjustable pressure regulator and a pressure gauge and lower the fuel pressure. it seems like your current regulator isn't working

 

[Black Sun 5.0]

I had an adjustable FPR installed and adjusted not too long ago in response to this issue. It didn't help.

 

[jrichker]

Codes? Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

Post the results and let us know what you get.

 

[Black Sun 5.0]

No codes, except for the vapor cannister, but I never had that hooked up.

 

[sleeper89]

when did the problem first occur?
have you had idle issues?
have you tried "clocking" your c&l?


i'm trying to isolate the issue so any info is helpful.

-steve

 

[Black Sun 5.0]

There's another thread with a similar issue that I jumped into. The car runs excellent. It used to have a real bad surge problem, but has since gone away. Every now and then you hear a bit of a 'wave' sound in the idle, almost like a mini-surge, but nothing that only the owner would notice. The issue started around the time I had my heads put in the car, but may have started before. The decline in mileage was gradual, not an overnight thing. The other post I'm in someone mentioned injectors being stuck open. Possibilty? I think it's the only thing I have not yet replaced.