1993 T-100 3vze - bad gas mileage

I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
engine.

it has 250,000 kms

I need to know where to start (i want to avoid a money pit)

I haven't done a tune up at all since i got it about 6 months ago so
I'm not sure what has or has not been done.

What are some of the key areas? Injector cleaning, O2 sensor, coolant
temp sensor, plugs / wires / cap&rotor?

There is a minor hesitation and it "feels" a bit underpowered (not by
much). It does start all winter (even when very cold)

Any ideas?

<superhawk@sympatico.ca> wrote in message
news:1141916293.288718.282520@u72g2000cwu.googlegroups.com...[color=blue]
> I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
> engine.
>
> it has 250,000 kms
>
> I need to know where to start (i want to avoid a money pit)
>
> I haven't done a tune up at all since i got it about 6 months ago so
> I'm not sure what has or has not been done.
>
> What are some of the key areas? Injector cleaning, O2 sensor, coolant
> temp sensor, plugs / wires / cap&rotor?
>
> There is a minor hesitation and it "feels" a bit underpowered (not by
> much). It does start all winter (even when very cold)
>
> Any ideas?
>[/color]
The 3.0 engine is known to be a little lacking in the power dept.

Being the truck is new to you I would check the need of a tune-up first.
That would include plugs, wires, distributor cap and rotor, air filter and
pcv valve. You may want to check the ignition timing as well, but if it has
never been disturbed it should be ok.

Next check to see that the engine is reaching normal operating temp. Just
check the temp guage in the dash when the engine is fully warmed, it should
be approximately in the center of the guage. This WILL NOT check the temp
sensor that the computer uses to determine engine temp, but it will tell you
if your thermostat is working correctly or not.

To check the O2 sensor and computer engine temp sensor you will need a scan
tool. The values for each will be read from the scan tool with the engine
fully warmed up. Also use the scan tool to check for any codes that may be
stored.

A few other things that effect fuel economy should be considered as well.
You mention "winter" and "very cold". Cold temps will have an effect on fuel
economy as well. The engine requires more fuel as it warms up, which reduces
mileage. Short trip driving will also effect mileage as well. Short trips
in very cold weather is even worse yet.

Thanks - that exactly the kind of info I was looking for.

Ver cold means around -10c which is around 0f, and the drive is around
5-6 miles each way (10-12 kms)

The temp guage reads fine. I knew that it wasn't the same sensor - is
there any point in checking this sensor? wouldn't it dump alot of extra
fuel if it is always reading cold?

I also have the issue that there is no tach. It might be idling a
little fast. I'll get someone that has a timing light w/ a tach on it
to check that out.

Sounds like a tune up would do it some good, but it may be more the
conditions of the driving. Do you think dirty injectors would affect
economy much?

Jason.

Mike wrote:[color=blue]
> <superhawk@sympatico.ca> wrote in message
> news:1141916293.288718.282520@u72g2000cwu.googlegroups.com...[color=green]
> > I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
> > engine.
> >
> > it has 250,000 kms
> >
> > I need to know where to start (i want to avoid a money pit)
> >
> > I haven't done a tune up at all since i got it about 6 months ago so
> > I'm not sure what has or has not been done.
> >
> > What are some of the key areas? Injector cleaning, O2 sensor, coolant
> > temp sensor, plugs / wires / cap&rotor?
> >
> > There is a minor hesitation and it "feels" a bit underpowered (not by
> > much). It does start all winter (even when very cold)
> >
> > Any ideas?
> >[/color]
> The 3.0 engine is known to be a little lacking in the power dept.
>
> Being the truck is new to you I would check the need of a tune-up first.
> That would include plugs, wires, distributor cap and rotor, air filter and
> pcv valve. You may want to check the ignition timing as well, but if it has
> never been disturbed it should be ok.
>
> Next check to see that the engine is reaching normal operating temp. Just
> check the temp guage in the dash when the engine is fully warmed, it should
> be approximately in the center of the guage. This WILL NOT check the temp
> sensor that the computer uses to determine engine temp, but it will tell you
> if your thermostat is working correctly or not.
>
> To check the O2 sensor and computer engine temp sensor you will need a scan
> tool. The values for each will be read from the scan tool with the engine
> fully warmed up. Also use the scan tool to check for any codes that may be
> stored.
>
> A few other things that effect fuel economy should be considered as well.
> You mention "winter" and "very cold". Cold temps will have an effect on fuel
> economy as well. The engine requires more fuel as it warms up, which reduces
> mileage. Short trip driving will also effect mileage as well. Short trips
> in very cold weather is even worse yet.[/color]

<superhawk@sympatico.ca> wrote in message
news:1141951551.550397.166900@j52g2000cwj.googlegroups.com...[color=blue]
> Thanks - that exactly the kind of info I was looking for.
>
> Very cold means around -10c which is around 0f, and the drive is around
> 5-6 miles each way (10-12 kms)[/color]

I would think that the short trips at that temperature are the cause of
your poor mileage. I have a 98 Tacoma and I lose around 5-6 mpg when it
gets that cold and I drive 10 miles each way.
[color=blue]
>
> The temp guage reads fine. I knew that it wasn't the same sensor - is
> there any point in checking this sensor? wouldn't it dump alot of extra
> fuel if it is always reading cold?[/color]

You can check it but I doubt it is the problem. If it was way off it
would also turn on the check engine light.
[color=blue]
>
> I also have the issue that there is no tach. It might be idling a
> little fast. I'll get someone that has a timing light w/ a tach on it
> to check that out.[/color]

If it's fuel injected the idle is not adjustable.
[color=blue]
>
> Sounds like a tune up would do it some good, but it may be more the
> conditions of the driving. Do you think dirty injectors would affect
> economy much?[/color]

Wouldn't hurt to do a tune up since you're not the original owner, but I
would check to see if it needs one first before you buy the parts. I don't
think dirty injectors would cause that either. If the injectors were that
bad you would have other symptoms or a check engine light.

[color=blue]
>
> Jason.
>
> Mike wrote:[color=green]
>> <superhawk@sympatico.ca> wrote in message
>> news:1141916293.288718.282520@u72g2000cwu.googlegroups.com...[color=darkred]
>> > I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
>> > engine.
>> >
>> > it has 250,000 kms
>> >
>> > I need to know where to start (i want to avoid a money pit)
>> >
>> > I haven't done a tune up at all since i got it about 6 months ago so
>> > I'm not sure what has or has not been done.
>> >
>> > What are some of the key areas? Injector cleaning, O2 sensor, coolant
>> > temp sensor, plugs / wires / cap&rotor?
>> >
>> > There is a minor hesitation and it "feels" a bit underpowered (not by
>> > much). It does start all winter (even when very cold)
>> >
>> > Any ideas?
>> >[/color]
>> The 3.0 engine is known to be a little lacking in the power dept.
>>
>> Being the truck is new to you I would check the need of a tune-up
>> first.
>> That would include plugs, wires, distributor cap and rotor, air filter
>> and
>> pcv valve. You may want to check the ignition timing as well, but if it
>> has
>> never been disturbed it should be ok.
>>
>> Next check to see that the engine is reaching normal operating temp.
>> Just
>> check the temp guage in the dash when the engine is fully warmed, it
>> should
>> be approximately in the center of the guage. This WILL NOT check the temp
>> sensor that the computer uses to determine engine temp, but it will tell
>> you
>> if your thermostat is working correctly or not.
>>
>> To check the O2 sensor and computer engine temp sensor you will need a
>> scan
>> tool. The values for each will be read from the scan tool with the engine
>> fully warmed up. Also use the scan tool to check for any codes that may
>> be
>> stored.
>>
>> A few other things that effect fuel economy should be considered as
>> well.
>> You mention "winter" and "very cold". Cold temps will have an effect on
>> fuel
>> economy as well. The engine requires more fuel as it warms up, which
>> reduces
>> mileage. Short trip driving will also effect mileage as well. Short
>> trips
>> in very cold weather is even worse yet.[/color]
>[/color]

<superhawk@sympatico.ca> wrote in message
news:1141916293.288718.282520@u72g2000cwu.googlegroups.com...[color=blue]
> I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
> engine. it has 250,000 kms
> I need to know where to start (i want to avoid a money pit)
> I haven't done a tune up at all since i got it about 6 months ago so
> I'm not sure what has or has not been done.
> What are some of the key areas? Injector cleaning, O2 sensor, coolant
> temp sensor, plugs / wires / cap&rotor?
> There is a minor hesitation and it "feels" a bit underpowered (not by
> much). It does start all winter (even when very cold)
> Any ideas?[/color]

Agh, yeah. EPA lists the 93' T-100 with having around 8 to 12 mph normally.
So, yeah, you're in the ball park. While a Tune up couldn't hurt, you
might try some mph gadgets. A clean air filter which will atomize the gas
before hitting the cylinders will give you a marginal increase in fuel
economy. A hydrogen assist tank; stuffing a little bit of hydrogen into the
cylinders to help atomize more of the gasoline before it hits the cylinders
creating boost and mph will run you around $200.00, but in the long run,
will be fun to pour water into the hydrogen assist tank to get more mph out
of your 93' T-100. Running around in 2wd instead of 4wd, oddly, should save
a couple of mph(s). Try not to race your neighbor to the local choke and
puke, easy off the red light, should bring it up to a respectable 16 to 17
mph.

check out [url]www.savefuel.ca[/url]

I've got it working in my 2001 RAV4, Tossed me up from 15 to 17mph to 33mph.
(The tune up using iridium plugs, new wires and a new air filter did most of
the work)
I'm saying nothing about keeping my foot out of the lead boot. :)

"William Hayes" <technofix.tx@comcast.net> wrote in message
news:pq2dnSepi_kaaI3ZnZ2dnUVZ_v-dnZ2d@comcast.com...[color=blue]
>
> <superhawk@sympatico.ca> wrote in message
> news:1141916293.288718.282520@u72g2000cwu.googlegroups.com...[color=green]
>> I'm looking to get more than 11mpg on my t100. it's a 4x2 with the 3.0
>> engine. it has 250,000 kms
>> I need to know where to start (i want to avoid a money pit)
>> I haven't done a tune up at all since i got it about 6 months ago so
>> I'm not sure what has or has not been done.
>> What are some of the key areas? Injector cleaning, O2 sensor, coolant
>> temp sensor, plugs / wires / cap&rotor?
>> There is a minor hesitation and it "feels" a bit underpowered (not by
>> much). It does start all winter (even when very cold)
>> Any ideas?[/color]
>
> Agh, yeah. EPA lists the 93' T-100 with having around 8 to 12 mph
> normally.[/color]

What ???? Epa mileage for that vehicle is 16-23 city and 20-28 hwy
depending on engine and trans combo.
[color=blue]
> So, yeah, you're in the ball park. While a Tune up couldn't hurt, you
> might try some mph gadgets. A clean air filter which will atomize the gas
> before hitting the cylinders will give you a marginal increase in fuel
> economy.[/color]

An air filter filters the air going into the engine, it doesn't atomize
gas or anything else.

A hydrogen assist tank; stuffing a little bit of hydrogen into the[color=blue]
> cylinders to help atomize more of the gasoline before it hits the
> cylinders
> creating boost and mph will run you around $200.00, but in the long run,
> will be fun to pour water into the hydrogen assist tank to get more mph
> out
> of your 93' T-100.[/color]

That hydrogen assist tank may lighten his wallet, but I'd bet that's the
only thing it will do.

Running around in 2wd instead of 4wd, oddly, should save[color=blue]
> a couple of mph(s). Try not to race your neighbor to the local choke and
> puke, easy off the red light, should bring it up to a respectable 16 to 17
> mph.
>
> check out [url]www.savefuel.ca[/url]
>
> I've got it working in my 2001 RAV4, Tossed me up from 15 to 17mph to
> 33mph.[/color]

Sure it did. Are you using the fuel line magnets also ?
[color=blue]
> (The tune up using iridium plugs, new wires and a new air filter did most
> of
> the work)
> I'm saying nothing about keeping my foot out of the lead boot. :)[/color]

I'm guessing that keeping your foot out of it made most of the difference,
but that's just a guess.

Thanks guys,

I'll do the tune up anyway-good preventative maintenance

The injector cleaning is about $120can so I'll forget about that.

I was also told be a mechanic that because my truck has over 250,000kms
that if I change the tranny fluid (automatic), I may cause it to start
slipping and it will likely need a rebuild.

I wanted to change it because it is visually dirty (getting brown).

Any risk here? My thoughts are that it won't be any worse than it is
not, and can only improve it. I don't see any issues will the tranny
now except for one thing:

If i'm on level ground and let off the brake, it won't always creep
forward unless i give it a bit of gas.
Is this common or a symptom?

Thanks.

<superhawk@sympatico.ca> wrote in message
news:1142086101.527679.105770@z34g2000cwc.googlegroups.com...[color=blue]
> Thanks guys,
>
> I'll do the tune up anyway-good preventative maintenance
>
> The injector cleaning is about $120can so I'll forget about that.
>
> I was also told be a mechanic that because my truck has over 250,000kms
> that if I change the tranny fluid (automatic), I may cause it to start
> slipping and it will likely need a rebuild.
>
> I wanted to change it because it is visually dirty (getting brown).
>
> Any risk here? My thoughts are that it won't be any worse than it is
> not, and can only improve it. I don't see any issues will the tranny
> now except for one thing:[/color]

It's really hard to say without being able to see trans fluid. If it is
really dirty and you change it it may cause the trans not to work at all.
Notice that I say "may". However, if you don't change the fluid it will
continue to get dirtier which will eventually cause the trans to fail
anyway.

The only tranny failures I have seen have been high on mileage vehicles
were the trans fluid was black (never changed) and the owner was having
trans problems. After the trans fluid change the trans wouldn't work at all.
Still, this is a very rare occurence. I have seen other transmisions in the
same condition and a fluid change worked wonders. There is no guarantee it
will fail but there is no guarantee it won't fail.

You say the fluid is "getting brown". If the fluid still has some pink
color to it I would say you should be ok. If you do decide to change the
fluid you mught want to consider getting a flush done to remove as much of
the old fluid as possible.

[color=blue]
>
> If i'm on level ground and let off the brake, it won't always creep
> forward unless i give it a bit of gas.
> Is this common or a symptom?[/color]

Wether or not the vehicle will creep forward when you take your foot off
the brake depends on the idle speed of the engine. The idle speed of
theengine is controlled by the comuter and is not adjustable. I would say
that is normal and nothing to worry about.
[color=blue]
>
> Thanks.
>[/color]

"Mike" <mik@localnet.com> wrote in message
news:Ik7Qf.17050$qg.1522@news01.roc.ny...[color=blue][color=green]
> > Agh, yeah. EPA lists the 93' T-100 with having around 8 to 12 mph
> > normally.[/color]
> What ???? Epa mileage for that vehicle is 16-23 city and 20-28 hwy
> depending on engine and trans combo.[/color]

Explain that to the EPA. Off the EPA web site.
[color=blue]
> An air filter filters the air going into the engine, it doesn't atomize
> gas or anything else.[/color]

Which explains dirty air atomizing gas quicker than clean air. Yeah. Ok.
Sure.
[color=blue]
> A hydrogen assist tank; stuffing a little bit of hydrogen into the[color=green]
> > cylinders to help atomize more of the gasoline before it hits the
> > cylinders creating boost and mph will run you around $200.00, but in the[/color][/color]
long run,[color=blue][color=green]
> > will be fun to pour water into the hydrogen assist tank to get more mph
> > out of your 93' T-100.[/color]
>
> That hydrogen assist tank may lighten his wallet, but I'd bet that's[/color]
the[color=blue]
> only thing it will do.[/color]

Ok. It is a bet. Buy one, use it for 30 days. If you are not satisfied with
it, send it back or sell it to me.
[color=blue][color=green]
> > I've got it working in my 2001 RAV4, Tossed me up from 15 to 17mph to
> > 33mph.[/color]
> Sure it did. Are you using the fuel line magnets also ?[/color]

Sorry, no fuel line magnets.
Cute, but only effective in ridding the fuel of magnetic particles that will
stick to the magnets.
Like trying to get a computer to use ECC ram on a workstation thinking the
random error where 15 billion to one chance is going to lock up the system.
Better chances with a lotto ticket.
[color=blue][color=green]
> > (The tune up using iridium plugs, new wires and a new air filter did[/color][/color]
most[color=blue][color=green]
> > of the work)
> > I'm saying nothing about keeping my foot out of the lead boot. :)[/color]
> I'm guessing that keeping your foot out of it made most of the difference,
> but that's just a guess.[/color]

Every little bit helps.

"William Hayes" <technofix.tx@comcast.net> wrote in message
news:b72dnVThYuXuBI7ZnZ2dnUVZ_vudnZ2d@comcast.com...[color=blue]
> "Mike" <mik@localnet.com> wrote in message
> news:Ik7Qf.17050$qg.1522@news01.roc.ny...[color=green][color=darkred]
>> > Agh, yeah. EPA lists the 93' T-100 with having around 8 to 12 mph
>> > normally.[/color]
>> What ???? Epa mileage for that vehicle is 16-23 city and 20-28 hwy
>> depending on engine and trans combo.[/color]
>
> Explain that to the EPA. Off the EPA web site.[/color]

Not sure what you are trying to say here but those figures are from the
EPA web site.
[color=blue]
>[color=green]
>> An air filter filters the air going into the engine, it doesn't atomize
>> gas or anything else.[/color]
>
> Which explains dirty air atomizing gas quicker than clean air. Yeah. Ok.
> Sure.[/color]

Not sure what you are trying to say here either. An air filter cleans
the air going into the engine. As the air filter gets dirty from diong it's
job it may restrict the amount of air going into the engine but it does not
let in dirty air. The atomization of the fuel occurs occurs at the fuel
injector as it sprays the fuel onto the back side of the hot intake valve.
[color=blue]
>[color=green]
>> A hydrogen assist tank; stuffing a little bit of hydrogen into the[color=darkred]
>> > cylinders to help atomize more of the gasoline before it hits the
>> > cylinders creating boost and mph will run you around $200.00, but in
>> > the[/color][/color]
> long run,[color=green][color=darkred]
>> > will be fun to pour water into the hydrogen assist tank to get more mph
>> > out of your 93' T-100.[/color]
>>
>> That hydrogen assist tank may lighten his wallet, but I'd bet that's[/color]
> the[color=green]
>> only thing it will do.[/color]
>
> Ok. It is a bet. Buy one, use it for 30 days. If you are not satisfied
> with
> it, send it back or sell it to me.[/color]

I don't waste my money on scams. I did, however, read the website. The
*inventer* of this device says that is has been in use since 1991 yet it is
offered for sale with an *introductory offer* as of right now. Of course
there are many *customer comments* ( as opposed to customer testimonials )
stating how mileage has almost doubled.

Now maybe it's just me but I have to question how such a fantastic
product that will double your mileage can be in production for 15 years
without me ever hearing a word about it before reading that website. I"m
sure if I purchased a product that would double my mileage I would be
telling everybody that I know how well it works. And this *amazing* product
is only available from that website. I would think that a device like that
( if it really worked ) would be flying off the shelves and should be
available in every automotive store in the country.

[color=blue]
>[color=green][color=darkred]
>> > I've got it working in my 2001 RAV4, Tossed me up from 15 to 17mph to
>> > 33mph.[/color]
>> Sure it did. Are you using the fuel line magnets also ?[/color]
>
> Sorry, no fuel line magnets.
> Cute, but only effective in ridding the fuel of magnetic particles that
> will
> stick to the magnets.
> Like trying to get a computer to use ECC ram on a workstation thinking the
> random error where 15 billion to one chance is going to lock up the
> system.
> Better chances with a lotto ticket.[/color]

The use of ECC memory is prevent data corruption, not computer lock up.
It is normally used on mission critical applications such as a high end
server.
[color=blue]
>[color=green][color=darkred]
>> > (The tune up using iridium plugs, new wires and a new air filter did[/color][/color]
> most[color=green][color=darkred]
>> > of the work)
>> > I'm saying nothing about keeping my foot out of the lead boot. :)[/color]
>> I'm guessing that keeping your foot out of it made most of the
>> difference,
>> but that's just a guess.[/color]
>
> Every little bit helps.
>
>[/color]