Gas mileage problem

[Alex Ethridge]

The problem: My recently-purchased 2003 CE is getting only 17 MPG.

I have owned three Toyota Siennas, two 2001 LE and now one 2003 CE. The two LEs consistently gave me approximately 22 MPG average mileage for my every-day driving. The CE, however, is giving me only about 17 MPG.

My driving habits have not changed between cars.

The particulars on the 2003 CE are these: The 2003 CE has only 8K miles on it. It was originally sold in November of 02 and was parked under a shed from August of 2003 until recently when it was taken out and the following work done:
replaced fuel pump
cleaned and sealed fuel tank
traced and repaired broken wire to fuel system
replaced fuel pump relay
fuel tank liner kit
replaced fuel filters
replaced fuel regulator
replaced fuel gauge assembly
replaced fuel pump harness
replaced main fuel pump relay
replaced all tires
changed oil

The exhaust pipe residue in almost non-existent and is light brown so there is no evidence there of overly-rich fuel mixture.

What else could I check or correct about this car that might help improve gas mileage?

[Black Sunshine]

This is all I've gotten out of my 2001 LE for years. It's been perfectly consistent though.

[Alex Ethridge]

I suspect engine ignition timing and you should, too. But, with all this non-adjustable computerized stuff, I don't know how to go about adjusting it. It probably requires some very expensive, specialized equipment.

Just tonight, for the first time with this 03 Sienna, I had an intermittent timing incident. I accelerated from a traffic light and had gross loss of power; but, the cylinders were firing consistently. I started doing my own mechanic work when I was old enough to drive, when everything was user-adjustable, pollution control was years in the future and computers existed only in science fiction movies. I am very familiar with this symptom. It indicates the ignition timing is off target. It lasted for about a quarter minute and corrected itself.

My guess is the timing on this car is off by at least 3 degrees all the time and maybe even the car's computer is defective.

[SiennaDriver]

My 2000 gets 17-19 MPG all the time, slightly less in the winter, since new and we drive with a feather foot.

Never understood how others got more.

[Alex Ethridge]

My driving is about half town streets and half interstate and I don't do featherfoot. I am almost always 10- to 15 miles over the limit and always 80 on the interstate and both my 01 Siennas are consistent at 22 MPG or very near 22 MPG.

Thus the disappointment with the 03 at five miles less on MPG.

[SiennaDriver]

Geesh. Around here 80 would get you taken in for reckless driving, which would also earn a criminal record and skyrocket insurance from already rape rates. They have no mercy.

I think what you have is what you get, but if someone posts magic for increasing mileage, great.

[Alex Ethridge]

I have read data from surveys that Alabama has one of the highest average (least enforced) interstate highway speeds. I am aware of that and that is why I watch my speed a little closer when I exit the state. I have passed many a cop monitoring traffic who did nothing when I went by at 85.

Interstate speed limits here vary from 50 to 70 and I'm always at least 10 over. Many make the joke here that they aren't limits, just suggestions.

Totally unrelated drivel: I passed an unmarked cop car at 88 MPH about a year ago who flashed me over but didn't ticket me. He acted unprofessionally and went into a cursing tirade over my driving and threatened he had the power to charge me with bogus crimes and put me in jail. To his dismay, I had my voice recorder running in my shirt pocket (legal in Alabama). He was outside his jurisdiction. I went to his city and presented the recording to the Mayor who presented it to the city council. His small-town position as Chief of Police was taken as well as his take-home car. They busted him back to patrolman.

[Zembonez]

Vehicles that are parked for extremely long periods of time can tend to have weird issues... but your mileage seems to be about what others here are getting.