Bad fuel mileage with TurboTweak chip?

[jrl2512]

I have had a turbo tweak chip in my car for a while now. The only problem I seem to be having is dreadful gas mileage, as in 147 miles to a tank. Is it normal to get bad mileage with Turbotweak chips? Now my fuel plugs look to be in pristine condition, so I think the tune is fine on that part. My car is mostly stock excluding the turbotweak chip. Any help would be appreciated.

 

[Jerryl]

Its normal with spirited driving. What is the afr on steady highway cruise?
FWIW . . . I get about the same in town, but 23-25 mpg on the highway.

 

[jrl2512]

Its normal with spirited driving. What is the afr on steady highway cruise?
FWIW . . . I get about the same in town, but 23-25 mpg on the highway.

I know I'm going to get shit for this but I have no idea. Is there any way I can check it?

 

[Jerryl]

You have a scantool?

 

[jrl2512]

You have a scantool?

No, since I'm pretty much self teaching myself with this, would you be so kind to recommend a good one?

 

[Jerryl]

It's ok not to have one when you get started. Just need to get one for sure though. Scanmaster, and Powerlogger later on.

 

[Jerryl]

Someone just posted the link in another thread.

http://www.vortexbuicks-etc.com/Scantool_Readings.htm

 

[TTA976]

What size injectors?

Joe

 

[earlbrown]

My first guess would be those stock injectors. After almost 30 years, they either have a shitload of miles on them, or spend some time settting (and gumming up)... or both.

 

[GNRick]

How old is the fuel filter?

 

[Turbo6Smackdown]

If the filter or injectors are "gummed", wouldn't his mileage get better and not worse? And maybe have some knock too?

 

[Raeban]

If the filter or injectors are "gummed", wouldn't his mileage get better and not worse? And maybe have some knock too?

Not exactly, an injector that isn't spraying right can cause fuel to puddle instead of atomize giving all kinds of transient and steady state mixture issues. Also, keep in mind, a reduction in torque at a given throttle setting just means the driver will end up using more throttle (and fuel) to compensate for their driving preference.

 

[earlbrown]

Not to mention, big blobs of fuel don't atomize and burn. The 02 will report a lean condition and, you guessed it... add more big blobs of fuel.


Spray patterns get compromised over time and gallons of fuel... Stock original injectors have seen plenty of both by this time.