Sick and tired of 11 MPG! Help!

[Turbojorge]

I don't know what to do. I've got 009's, and a hotwired 307. FP line off is 39psi. It's got an extender chip, with a T+ (if that matters).

I use to think crappy gas milage was due to the RA93, but it's not. I haven't gone past half throttle in months, since it's my only car and I need to use it to work everyday. AC is on about 50% of the time. I don't get it?

What could be going on?
TIA.

 

[BJM]

You really haven't given enough info. Starting with the basics, is the chip burned for those injectors? What does a scan tool say? In particular are the BLMs pegged at 150 indicating the ECM is pouring fuel into it? If the BLMs look okay (not pegged at least) are you getting O2 cross-counts indicating the O2 sensor is working? If your T+ is set wrong (the different settings scale the airflow effectively fooling the ECM) making the ECM think your are getting tons of air the computer will fuel accordingly and then trim back fuel. It will get stuck when the BLMs get down to the lower limit of 90 and leave you richer than it wants. The cross counts should be non-existant or very low and the INTegrator values will also be around 90.

I just changed my stock injectors and am now getting better mileage because a couple were really dirty, are yours known to be good?

If all that checks out, a weak ignition can cause mileage issues without actually seeming to run poorly.

 

[Quick6'n'-K.C.]

take your shoes and socks off and glue thumb tacks to the gas pedal-
i guarantee that you will get 2mpg more-

also, maybe your gas tank leaks and evaporates before you notice it?

 

[petesgn]

Maybe somebody is stealing your gas?

 

[TurboJim]

Even with my chip Jorge?

 

[Turbojorge]

Jim: I don't have any of your street chips. The two that I have from you are race chips (26* and 30*). I only run them at the track.

Pete: No, But I think my neighbors are about to start seeing their gas disapear before their eyes really soon.

Quick 6 KC: I can honestly tell you that I have no idea how much boost I'm currently running. I haven't gone WOT in over a month. The needle in my boost gauge must be like: "Come on man, let me move a little, let me see at least 3, or 4, please. I'm tired of just sitting here dammit." I've inspected the tank over and over. It doesn't leak.

BJM: Chip is for 009's, by Bob Baily. BLM are allways around 126-130. 02 count are good. 02 sensor is the heated AFS74 less than a year old. T+ settings are good. INt are in the low to mid 130 all the time. Coil pack/ modual (GM) are about a year old. Plugs are about the same. I've had the same cables for 3 years now. They are the ones Red Armstrong sells. Injectors are 5 years old. I've run xylene threw them a bunch of times so I ASSume they are clean. How do I check if they are bad?

Dumb question #1: Would a weak starter have something to do with an ignition problem?

I think I'll change my plug tommorrow.

 

[BJM]

Check bleed down of the fuel pressure with the car off. If bad then you know you have a bad injector. If good, you may still have a bad injector. My car was like that, held pressure for hours but bled down progressively and was getting harder to start, if restarted after 10 minutes, no problem. Wait 30 minutes, it would take two tries at least. Wait overnight and again no problem because whatever leaked down had dried up again.

I went from 12 MPG to 15.5 MPG and I use healthy throttle when driving. My injectors were stockers though and very dirty.

 

[Bmason]

Silly questions!

Jorge:

How about your converter not locking, or tranny/converter slipping? Is your tire pressure where it should be or a brake shoe/caliper sticking?

Mechanically, is the motor sound? Have you performed a leak down or anything? You're mileage is about what I get in my truck!

I'll be down your way sometime around the end of next week, should I bring my old 009's and chip to you? I doubt if you have an injector(s) leaking that bad, but you never know! You can swap them out and see what happens.

-Bobby

PS - I'm not bringing the car this time, but we can still do Moroso.

 

[Turbojorge]

Is a Bleed down and a leak down the same thing? If so, how do I perform it/each?

Bobby: I can't figure out how to set the converter to lock up with the extender chip. I have digital climate control in my car and instructions say : "Climate Control equipped cars will need a switch connected to the ECM since they don't have an AC on switch." My question is, what the heck does that mean.

Mechanically sound motor? I guess. Head gaskets are still where they need to be. No rod knocks or detenation. 167,000 original mile motor, I travel 30-50 miles a day these days, seems O.K. to me. How can I check?


Tire pressure is good. Rear tires are a little low (25 psi), but thats how the've been all their lives.

Bobby, I'll send you an E-mail.

 

[86gn]

I think for the bleed down test for the fuel injection system is to turn key on let the pump prime then turn it off and see how long the pressure holds @ the gague.If it does not hold the pressure there is a problem somewhere in the injectors or FPR or the return line.

JOhn

 

[Bmason]

Jorge:

(1) I've sent you email.

(2) I would have thought that your BLM's would be a lot higher since you stated that your base fuel pressure is only 39psi. I'm definitely surprised to see a BLM of 126 (taking fuel out) and only 130 max. Are you sure about the settings on the T+?

(3) Leak down / bleed down (see email)

(4) If you're running 50 miles a day, why not air up the tires where they should be? Not that this is your whole problem, but I can assure you that you'll get better mileage from both your gas and tires! I don't have to start the low air pressure in radial tire sermon, do I?

(5) One last thing, are you saying that you get a little over 160 miles between fillups, that's scary?

-Bobby

 

[BJM]

ttt

Any progress with this?

 

[BLACKHAWK38]

I get better mileage ,WHEN I>>>

Originally posted by BJM
ttt

Any progress with this?

IN my turbo riviera convertible, when I have my foot in it and most trips are short, 15 mpg trip total adverage is about the worst.

My mileage is better in hot weather and when i keep the fan off an let the coolant temps run high approching 200

Mileage is better when my tire pressure is a good 35 psi

Milegage is better when I use lucas fuel treatment.

When I use lower viscosity oil my milegage is better, try some 0W30 mobil one.

My best ever milegage lately is 21 mpg adverage combined trip.


Highway's vary in ride quality, the smoother the ride the better mpg that highway will give.

REGARDS