Ok, my 88 is getting 10mpg lately!
Ran seafoam.
I replaced the oxygen sensor, and adjusted the tps,
also checked/moved the air temp sensor to the airbox,
but no improvment. (maybe should replace that one too)
should I look to the coolant temp sensor, and fuel pump next?
Run more seafoam?

 

When my tranny fluid was low it affected my mpg. Any exhaust leaks? Vacuum leaks?

 

Its a manual trans. I just filled it with redline.
No leaks, besides I don't think any leaks would account for this much usage
it sounds like a sensor is bad, or telling it to dump fuel.
I'm going to keep replacing stuff, just wanted to know what ppl thought about next thing to go on.

Update: I'm going out to double check on the leak idea

 

I had a '91 F150 that the coolant sensor for the ECM went bad and it was gettig horrible mileage and would almost stall at a stop light/sign. Is it acting like that?

 

Yeah, it does that sometimes, it also "searches" as it idles I.E. it fluctuates.
at idle. I read some where to disco the idle stepper control, but I did that and though it idles nice and low now (rumply-bump)
this did not improve the mileage problem.

Any RENIX guys wanna jump in too? lol

 

Yeah, Im so not a Renix guru.

 

Oh, but I really appreciate the help!

The coolant sensor has not been replaced yet, I wish I could just go out, get a bunch of sensors, and be done with it!

 

Me too. But something tells me that might get expensive real quick.

 

Lol...my gas mileage is getting pricey too!

 

Wow, less than 24 hrs later I find this post 6 rows back!

 

HELLO?

Guess I'm on my own with this one..............

 

Did you try the coolant sensor?

 

Just Empty Every Pocket

Well mine went from 17 to 12 when my cat was about to take a dump along with my CPS I also needed a new fuel filter, but I don't know anything a bout RENIX sorry.

 

Hey thanks!

I have not tried the coolant sensor yet, but I will.
And thanks for the all the advice.

Regarding the cat/cps I'm putting new exhaust in soon, so might as well replace cat. and might as well replace cps.....cheap insurance.

 

I'm not positive if the MAP sensor controls anything off-idle, but it's worth checking out. It'll only take you about 30 seconds.