Been chasing this for a while. Car has 250,000 miles.

New plugs and wires
New cap and rotor
Synthetic oil
new fuel injectors
new o2 sensor
new fuel filter
new tires
alignment
Ignition timing set at 15 degrees btdc
No exhaust leaks before o2 sensor
new pcv valve
no fuel leaks
no brake drag
New air filter
cleaned egr valve and ports
compression 150 psi on all cylinders

strong gas vapor smell when it’s hot outside possibly evap or charcoal canister?

What could be causing poor fuel economy in this thing? Am I missing something?

 

That is quite the parts list you have there. impressive to put that much effort into such a high mileage engine.

I only have one question, do you know when the valves clearances where checked and adjusted last?

Have you checked the fuel pressure regulator?

 

Never checked valve clearance as they sound good and quiet. I guess I could bust out the feeler gauges and check though.

FPR was taken off and inspected and functions normally. No fuel leak at the oring and no rupture in the diaphragm.

I bought this car for 800 bucks and drive it around 700 miles a week for deliveries. It runs great.

 

Quiet can actually be bad..... Tight valves are quiet, there should always be a little bit of that "sewing machine" chatter with these engines. Most times that I have seen where clearances are an issue have been when the valve clearances tighten up, really quiet. This can cause unwanted camshaft overlap and poor power and MPG.

 

So I did the valve lash adjustment today. Only had to loosen up a couple on the exhaust and only one on the intake side. They weren’t that far out of spec either. So we shall see if it helps my MPG in the next few days.

Maybe I just have a heavier foot than I realize.