Real bad gas milage

[Imp558]

The extended crank and rough running initially points to something wrong.  That may or may not cause mileage as bad as your son is seeing.  His right foot might be part of that problem.  I would check fuel pressure.

 

 

Here's a scenario: Bad diaphragm on regulator allowing the fuel rails to cavitate causing hard starting and allowing engine vac to suck a certain amount of fuel right in causing high fuel consumption.

[Schurkey]

You are correct on both the Mustang supplier and the bar. And yes "Honey" is the norm here in Central Pa. And people also say we have our own accent in Central Pa. I dont hear it at all lol. Its not a bad city, but we are fighting to survive since the railroad is pretty much non existent.

What is the actual name of the bar?  Still in business, I presume?

 

Yeah, you folks have an accent, but it's fairly subtle.

 

Railroad--the bus testing offices and repair facility is (was???  I haven't been there in decades) in one of the locomotive-repair buildings.  When the railroad pulled out of Altoona, they left a lot of infrastructure that is under-used.

 

There is a "mountain" pass not far out of town--I was there once but I don't remember the driving directions--that has a H-U-G-E long curved train track.  I think there's a big bronze placque along side the highway for the tourists to read, along with seeing the train tracks.

 

The Johnstown Flood still gets some recognition there.  I don't think I ever made it to Johnstown.  I did read the book by David McCullough.

 

I remember strip bars, and more friggin' porno shops than I'd ever seen before.  Screwing must be big business there.  I'd have to drive 90 miles to find a strip bar around here, and there's ONE porno store locally.

 

 

 

 

 

Back on topic:  Extended cranking?  Check fuel pressure at prime with key on. ( i.e., you turn the key "on", you should have two seconds of fuel pump running, and it should hold pressure after the pump shuts off.)  If the fuel pump relay, harness, or ECM fuel pump driver failed, the engine will have to crank long enough to build oil pressure before the pump will turn on.

[dogginred90]

Ok so I went today and tested fuel pressure. First prime I got nothing. Second time I primed I got 40 with constant leak down. With I. 2 seconds I was at 0. I started it and it hung at 35. Injectors or regulator? I am not going to keep throwing money at this thing. I will check my gauge with my truck just to make sure it works right.

[Imp558]

Could you rig a piece of hose onto the fuel return and vacuum port on the regulator? Then if it runs out it'll be visible.

[dogginred90]

Just went out and tested the gauge on my vert. It held steady, so the gauge is good.

[Galaxie500XL]

Ok so I went today and tested fuel pressure. First prime I got nothing. Second time I primed I got 40 with constant leak down. With I. 2 seconds I was at 0. I started it and it hung at 35. Injectors or regulator? I am not going to keep throwing money at this thing. I will check my gauge with my truck just to make sure it works right.

Least expensive and easiest thing to replace would be the regulator...

[Imp558]

Could you rig a piece of hose onto the fuel return and vacuum port on the regulator? Then if it runs out it'll be visible.

 

If the fuel doesn't bleed off one of the hoses it's a leaky injector or the pump isn't holding pressure. It's probably a regulator, the fuel pressure is in spec according to Alldata but on the low end. Key on Engine off 40.5 - 47.0 PSI, with Vacuum applied 3.0 - 10.0 lower. Some pretty tight tolerances there, lol.

[dogginred90]

Wouldn't pulling the the vacuum line off the regulator and if it's wet then the regulator is bad

[Imp558]

Yes, the return will be wet regardless. I bet that vacuum line is wet though with the fuel consumption issue and bleed down.

[55trucker]

To test the FPR diaphragm you'll need a hand held vacuum pump. Disconnect the vacuum tube from the MAP end, connect the vacuum pump, with No vacuum the engine will be hard to start as the FPR will be at full flow and the engine will stumble contiunally. Attempt to pull at least 12" on the pump, (in an earlier post you mentioned that you replaced ALL the vacuum lines.....I take it that included the FPR vacuum tube) if the vacuum pump registers then the diaphragm is still good, if you can't pull any vacuum then the diaphragm has failed. If you Can pull vacuum start the engine with the pump still attached, you'll find there will be no change in the engine idle regardless if you have 12" or 19" vacuum pulled. Assuming no vacuum leaks elsewhere at engine idle the MAP will see approx 16" of vacuum. This can be read via a vacuum gauge connected to the vapor canister solenoid port under the PCV port beside the EGR.

[dogginred90]

Thanks 55trucker I was trying to figure out how to test while starting the car. 20 degrees doesn't sound like a good time to tear the intake off just to check a line. I will pull the vacuum line of the Map sensor and hope for the best

[dogginred90]

Ok gentleman. This car has me confused. I tested the regulator today and it held pressure. Hooked everything back up and the car started just fine. Tried it a couple times and every time it fired right up. No long crank, no multiple tries. First try every time. I am guessing a vacuum line fell off and I didn't know until I put it back on. I am so confused, I will keep checking it everyday to see if it stays fixed lol

[Galaxie500XL]

Sounds like a vacuum leak, and you've fixed it.  Proof will probably be increased fuel mileage.  Sometimes the simple things are the hardest to find. 

[dogginred90]

Yea tell me about it. It had to be the ones at the MAP sensor, they was the only ones I messed with. Time will tell that's for sure

[dogginred90]

Ok so an update on my MPG saga. With my driving roughly 80 miles and my boy the rest. We got 16 mpg this time around. Some highway, but most city driving. It's better when I drive. So this tank full he will do all the driving and I will check back. And this car still starts first try every time now. Still confused about that

[Nas Escobar]

16 city sounds about right. I usually get 15 all city in my Cutlass, 20 mixed driving, and 23 mostly highway.

[55trucker]

 We got 16 mpg this time around. Some highway, but most city driving. It's better when I drive.

 

But you're still tying to find an appreciable mpg in the middle of the winter, that's just not going to happen, you need to do your fuel mileage monitoring in the summer.