My gas mileage sucks... how about yours?

[grandpaslincoln]

:stupid:

[Grand Marquis GT]

Yeah...

I converted to 4bbl, and while I only gained maybe 1mpg, the power is much more!!!

[FatNasty]

As of now i don't have the expertise to do anything major, especially with engines and other major stuff. I'd like to learn, but i dont know anyone who knows how either, high school doesn't even have an auto shop class. All i can do is smaller repairs, and electrical type stuff. Switching engines or putting in a 4bbl would be a little out of my league. Hell, i didn't know what a 4bbl was a month ago.

[moneypit]

As of now i don't have the expertise to do anything major, especially with engines and other major stuff. I'd like to learn, but i dont know anyone who knows how either, high school doesn't even have an auto shop class. All i can do is smaller repairs, and electrical type stuff. Switching engines or putting in a 4bbl would be a little out of my league. Hell, i didn't know what a 4bbl was a month ago.

In that case, the best advice would be to get the codes pulled.

[Blaze86Vic]

I'm still having running problems, I just got 13.2mpg all 65mph highway too. I really need to get this fixed, but I can't find what it is that's causing it. Already diaged and replaced a ton of crap. Back to pot luck guess now. Next guess is that the MAF sensor is dieing.

[Grand Marquis GT]

You replaced all the injectors, mang?

[Blaze86Vic]

Here is what I have replaced in trying to fix this problem with all new parts.

Air filter, fuel filter, fuel pump, spark plugs, plug wires, coil, distributor cap and rotor, injectors, and fuel regulator.

[mrltd]

May the missing BAP has something to do with it.

[Blaze86Vic]

Like I said before, it worked great for the past 6 years/98,000 miles, so that if it is even needed on this setup, is not a problem. I'm not sure if there is need for one on this setup. 92 Cougar ecu is a MAF computer.

[88grandmarq]

Have you checked the ECM For trouble codes ? Have you replaced the T/stat any time recently, 195 Degree is best for power and efficiency.

And MAF operating systems still require some sort of load or pressure sensor (baro pressure sensor) MAF Fox body Mustangs had them and most of the V8 T-birds and Cougars I have worked on have them.
all the MAF conversion kits I have seen tell you to leave the MAP sensor in place with the electrical connector hooked up, but leave the Vaccum hose OFF and let the sensor vent to outside air. The ECM uses this to measure atmospheric pressure which helps determin enging load and can fine tune A/F based on that info.

[Blaze86Vic]

ECU pulled no codes. Just needlessly replaced my T-stat last week. My power problem is not a fine line of not running good and running great. It's so bad that in 1st gear the engine can't accelerate the car past 5,080rpm.

Also, like I said before, it's worked great for 6 years. Don't mean to be short or ungreatfull for the help, but I think it's a little odd to point at a "design flaw" as the cause of a problem that just started after 98,000+ miles (from ocean level to 10,000 feet high in the rocky mountains). Also, it actually was not a MAF "conversion" since the engine and ECU were both originaly MAF equiped. Next time I talk to my Dad if I remember I will ask about the BAP, but unless I have one and it has gone bad, that is not the cause of this problem.

[gadget73]

5k is not exactly weak for a stock SBF engine. Most of these things with an auto in stock form can't see past 4800 as thats where the trans shifts. 5k is pretty near the redline anyway, so its not like its a sign of weakness to not be able to break it. Probably shouldn't be spinning over that anyway. You also have to consider, this is an engine with nearly 100k on it. its just not as strong as it used to be. That said, 13.2 mpg is horrible. My original neglected engine got 11 and from just simple running cleared itself to 14 mpg. That was a 125k neglected, many many times overheated lopo that had been kicked in the ass steadily for almost 2 years before I got it.

Have you by chance cleaned the MAF? That seems to help sometimes. Standard method is to use electrical contact cleaner as it doesn't leave a residue and is usually plastic safe. Pull the MAF and spray down the wires, let it air dry, and re-install. Might not be a bad idea to reset the ECM too. Oxygen sensors are another wear item, if yours are original with 100k on them.

[Archangel]

My last week's mileage is 8.93 but that's with lots of flooring while running on manifolds only (no exhaust system at all). Until then combined mileage was steady 16, with most of the freeway driving done at 85 mph and faster, while the city take-offs were exactly that - pedal to the metal on the green light. Also I had about 250lbs of stuff in the trunk, and my rear tires are much wider than stock. The car currently has a much better exhaust, only one sand bag (instead of 4), and I'm also trying to take it very easy on accelerator. And in about a month I'll be due for an oil change, which will be combined with SeaFoam-ing and installing new O2 sensors - hope that'll help bring her back in the 20+ highway mpg.

[88grandmarq]

ECU pulled no codes. Just needlessly replaced my T-stat last week. My power problem is not a fine line of not running good and running great. It's so bad that in 1st gear the engine can't accelerate the car past 5,080rpm.

Also, like I said before, it's worked great for 6 years. Don't mean to be short or ungreatfull for the help, but I think it's a little odd to point at a "design flaw" as the cause of a problem that just started after 98,000+ miles (from ocean level to 10,000 feet high in the rocky mountains). Also, it actually was not a MAF "conversion" since the engine and ECU were both originaly MAF equiped. Next time I talk to my Dad if I remember I will ask about the BAP, but unless I have one and it has gone bad, that is not the cause of this problem.

You say it pulled no codes... what does that mean, no codes at all? or just code 11 (system pass)
what mode did you pull codes? KOEO, continuous or KOER?
You can have trouble codes in one mode but not in the other.

I was not Implying the lack of a BAP was your problem, only pointing out that a MAF system still needs one.

[Blaze86Vic]

5500rpm was the factory redline, and most redlines are limited by valve train, not the crank flying apart. So with a fresh springs the factory redline should be no problem at all. Shift point is not my limitation. When I say can't get over 5080, I mean that holding first it can't get over 5080rpm. It's not a tired engine by far, yeah 100,000 miles, but very well maintained. Always had quality paper filters no K&Sucks on it, EVERY 3000miles comes with new oil and Motorcraft FL1-HP oil filter.

Not sure what the difference between all those modes of code pulling are. I used a STAR, the big T shaped thing to pull the codes. I always get one code for smog pump thing not being there, but no other codes.