Calling all Toyotas

[daverods]

If you are reading this you are most likely a Toyota owner or have owned one in the past. I have grown up with Toyotas my entire life, mainly because my dad was a fully certified Toyota mechanic. We all know that 90% of Toyotas older cars are virtually indestructible, unless they fall victim of being hit by a large truck.

This brings to my current dilemma. I am currently driving a 91' Toyota Paseo, 5 Speed Manual, with roughly 280,000km, and no modifications as of right now. I was initially impressed to see that I got 18% above the estimated fuel mileage of my vehicle but now after seeing the numbers from some of the other members of ecomodder I realise there is alot of room for improvement.

I know that the smaller displacement Toyota engines aren't very thirsty for fuel so im pretty confused why im not getting below 7L/100km (33.6 mpg) combined highway and city.

I have a handful of theories as to why this might be happening.

• Unusually high idle on cold start (2000rpm)
• Warm idle speed of 1000rpm (seems a bit high)
• Known vacuum leak on intake (intake pipe is broken right after the fitting on the throttle body )
• Alignment issue with front suspension (had rotten right lower control arm replace 4-5 months ago without re-alignment )
• The front of the car sits considerably higher than the rear (looks about 2-3 inches) essentially turning the car into a sailing ship on the highway when it is slightly windy (my guess is front springs were replace with aftermarket springs that are for the wrong application)

Now before anyone tears me apart and says, "WHY DOESNT YOUR DAD JUST FIX IT!?!" I'm just wondering if these issues would be enough to keep me from getting 6L/100km (39.2 mpg) or even better? I am already implementing an extremely conservative driving style, incorporating hypermiling driving skills.

Oh BTW everyone is allowed to post suggestions, not just the Toyota owners!

Keep on hypermiling!

[Arragonis]

Well, keeping on top of maintenance and fixing stuff when its wrong is definitely in the list of economy tips, so I think the answer is fixing these things certainly wouldn't do any harm.

None of them - except maybe the springs, and even then only if you use new replacements - would be all that expensive to put right over a weekend ?

Daox has a Paseo that is on 53+ MPG so it seems possible to do better. If you use the search option (top, right hand side) there are a few threads on Paseos too.

Good luck.

EDIT - Plus its winter, which kills FE

[darcane]

Originally Posted by daverods

If you are reading this you are most likely a Toyota owner or have owned one in the past. I have grown up with Toyotas my entire life, mainly because my dad was a fully certified Toyota mechanic. We all know that 90% of Toyotas older cars are virtually indestructible, unless they fall victim of being hit by a large truck.

The BS is getting deep here...

Toyota makes decent enough cars, but there's no need to deify them (well, maybe the GT-86/FR-S/BRZ. Damn, I lust over that thing!). I've done enogh major engine repairs or replacements on Toyotas to know that they are no where near indestructible.

Originally Posted by daverods

I have a handful of theories as to why this might be happening.

• Unusually high idle on cold start (2000rpm)
• Warm idle speed of 1000rpm (seems a bit high)
• Known vacuum leak on intake (intake pipe is broken right after the fitting on the throttle body )
• Alignment issue with front suspension (had rotten right lower control arm replace 4-5 months ago without re-alignment )
• The front of the car sits considerably higher than the rear (looks about 2-3 inches) essentially turning the car into a sailing ship on the highway when it is slightly windy (my guess is front springs were replace with aftermarket springs that are for the wrong application)

• High cold idle is probably not a big concern by itself. This is a small percentage of your driving time, unless you do a lot of little trips.
• Not sure of your car's specs, but this sounds high.
• Uh... yeah, fix the leak. That is likely the cause of the high idle and could cause unusual driveability problems, maybe even low fuel economy.
• Yes, check that. Significant alignment issues will also lead to unusual wear patterns on the tires.
• yes, this is hurting you a little. Lower just the rear and aerodynamic drag increases.

I'd fix the vacuum leak first and get an alignment and see what it does. If it's still low, look for other maintenance problems and adjust driving habits.

[user removed]

Set the toe on the front end with a tape measure.Get it close to 0 or just a little toe in.
Fix the manifold problem, the high idle and fast idle cold are killing your mileage.
The manifold problem is also causing the fuel mixture to be incorrect to different cylinders with the system trying to compensate by enriching the mixture to the cylinder that is getting unmetered air (vacuum leak).

The rear end ride height is probably relatively minor as far as mileage. You could either lower the front or raise the rear depending on how much the rear is sagging.

regards
Mech

[daverods]

Originally Posted by darcane

• High cold idle is probably not a big concern by itself. This is a small percentage of your driving time, unless you do a lot of little trips.
• Not sure of your car's specs, but this sounds high.
• Uh... yeah, fix the leak. That is likely the cause of the high idle and could cause unusual driveability problems, maybe even low fuel economy.
• Yes, check that. Significant alignment issues will also lead to unusual wear patterns on the tires.
• yes, this is hurting you a little. Lower just the rear and aerodynamic drag increases.

Im well aware of the adverse affects of not keeping your car in good repair. I already know that the vacuum leak wouldn't be correcting the high idle issue or helping the situation at all but it is not affecting drive-ability.

As for the alignment I know that it will make the tires wear unevenly but they are old, weather cracked, and with 60% tread left so im not terrible concerned for their well being. I'm just curious as to whether it will have a significant effect on the FE. I guess once I get that fixed ill make a little report of it.

Originally Posted by Old Mechanic

The manifold problem is also causing the fuel mixture to be incorrect to different cylinders with the system trying to compensate by enriching the mixture to the cylinder that is getting unmetered air (vacuum leak).

My car has a MAP (Manifold Absolute Pressure) Sensor which from my knowledge shouldn't be affected by any changes before the throttle body. Correct me if I'm wrong. Always interested in hearing other peoples piece haha.

[daverods]

Originally Posted by Arragonis

Daox has a Paseo that is on 53+ MPG so it seems possible to do better. If you use the search option (top, right hand side) there are a few threads on Paseos too.

Good luck.

EDIT - Plus its winter, which kills FE

I have seen Daox's Paseo and im totally jealous of the FE he is getting! And the only solution to winter is to move south of the border. Maybe if I master the art/science of hypermiling I will save enough money to move somewhere warm

[Arragonis]

BS seems a little strong here, people like different cars - their choice.

Fix it and let the fun saving money begin.

[Arragonis]

ps

http://ecomodder.com/forum/showthrea...nomy-5322.html

[user removed]

Originally Posted by daverods

If you are reading this you are most likely a Toyota owner or have owned one in the past. I have grown up with Toyotas my entire life, mainly because my dad was a fully certified Toyota mechanic. We all know that 90% of Toyotas older cars are virtually indestructible, unless they fall victim of being hit by a large truck.

This brings to my current dilemma. I am currently driving a 91' Toyota Paseo, 5 Speed Manual, with roughly 280,000km, and no modifications as of right now. I was initially impressed to see that I got 18% above the estimated fuel mileage of my vehicle but now after seeing the numbers from some of the other members of ecomodder I realise there is alot of room for improvement.

I know that the smaller displacement Toyota engines aren't very thirsty for fuel so im pretty confused why im not getting below 7L/100km (33.6 mpg) combined highway and city.

I have a handful of theories as to why this might be happening.

• Unusually high idle on cold start (2000rpm)
• Warm idle speed of 1000rpm (seems a bit high)
• Known vacuum leak on intake (intake pipe is broken right after the fitting on the throttle body )
• Alignment issue with front suspension (had rotten right lower control arm replace 4-5 months ago without re-alignment )
• The front of the car sits considerably higher than the rear (looks about 2-3 inches) essentially turning the car into a sailing ship on the highway when it is slightly windy (my guess is front springs were replace with aftermarket springs that are for the wrong application)

Now before anyone tears me apart and says, "WHY DOESNT YOUR DAD JUST FIX IT!?!" I'm just wondering if these issues would be enough to keep me from getting 6L/100km (39.2 mpg) or even better? I am already implementing an extremely conservative driving style, incorporating hypermiling driving skills.

Oh BTW everyone is allowed to post suggestions, not just the Toyota owners!

Keep on hypermiling!

A broken intake pipe, before the throttle body is not a vacuum leak. Vacuum can only exist after the restriction of the throttle plate. This is assuming you are talking about the pipe from the air filter to the throttle body (not sure the information is confusing, at least to me).

No vacuum leak exists after your clarification just unfiltered air entering the engine through the defective pipe. It would not be "after" the throttle body or it would be a vacuum leak. It must be before the throttle body to NOT be a vacuum leak. Regardless, something is affecting the idle speed which should be around 600-700 RPM and it may also be affecting the cold high idle speed since it is affecting the hot idle speed.

Possibly a leaking intake manifold gasket, or some other loss of integrity in the pathway from the throttle plate to the intake valves. If this exists then what I said earlier still applies. The crack in the intake pipe does not explain the high idle.

regards
Mech

[darcane]

Originally Posted by daverods

As for the alignment I know that it will make the tires wear unevenly but they are old, weather cracked, and with 60% tread left so im not terrible concerned for their well being. I'm just curious as to whether it will have a significant effect on the FE. I guess once I get that fixed ill make a little report of it.

I mentioned the tire wear, not because I care about the well-being of your tires, but because it's one thing that will indicate significant alignment issues. If you are getting unusual wear, then it is taking additional power to move your car.

Originally Posted by daverods

My car has a MAP (Manifold Absolute Pressure) Sensor which from my knowledge shouldn't be affected by any changes before the throttle body. Correct me if I'm wrong. Always interested in hearing other peoples piece haha.

Is the leak before the throttle body or after? If it's before, it's not a vacuum leak (no vacuum before the throttle body). If it's after, it is a vacuum leak and can affect mpgs and your idle, even on an engine with a MAP.