Topic: 22ret horrible gas mileage?

[MrFatEggs]

I've been driving my 1987 Toyota with the 22rte in it and it's been driving good and seems like it has plenty of power. The only problem I'm having is that it's only getting 6-10 mpg? I don't know why. Does anyone know where and what to look for that would be making it get such terrible gas mileage?

[emsvitil]

The fuel injection pulse dampner (fuel rail close to throttle body) could be leaking.

[gnob]

Make sure you don't have an exhaust leak around the manifold or o2 sensor

[Gnarly4X]

...1987 Toyota with the 22rte ...getting 6-10 mpg? 

There are most likely 4 possibilities:

1 – you have a real heavy right foot

2 – you are miscalculating the MPG

3 -  there is a gross gas leak – which you would be able to smell or see

4 – the engine is attempting to burn excessive fuel, which should be evident by looking at the spark plugs

There may be other causes? 

Gnarls.

[emsvitil]

5.  Someone is taking the gas at night.

[Gnarly4X]

5.  Someone is taking the gas at night.

Good call.. I knew I was missing something!!

Gnarls.

[Gillesdetrail]

What is your timing?

[EASYRYDERDANGER]

I agree with checking exhaust leak, manifolds and downpipe elbows are known to crack like crazy.  Also doesnt hurt to check the voltage from the 02, look in your diag box for easy access pin, see if its staying stuck rich or lean and see if it even switches.  A quick check you can do is see if your wastegate rod moves freely. I personally had a stuck closed waste gate causing it to boost all the time, but I also hit fuel cut at high rpms...  I know the stock turbos will crack internally near wastegate flap, sometimes they can become bound or restricted.  Just a bunch of long shots but may cause your ecm to drop more fuel?

[MrFatEggs [OP]]

Okay I had a huge exhaust leak and now that's completely fixed but it's still only getting 13-15 mpg. I feel like it should be getting a lot better. I have not checked the o2 sensor, and also my water temp and oil temp are not hooked up and someone said it could be the water sensor??

[Snowtoy]

W/o info from the water temp sensor, the ecu will assume the engine is cold and continue to run in "warm-up" mode, causing a significant drop in mpg's.

[MrFatEggs [OP]]

Okay, I know where the water temp sensor is, but I'm not sure where the wire is that goes to it, is there a way to trace it?

[Gnarly4X]

Trying to analyze gas mileage over the internet is like sniffing flowers through your butt.

Gas mileage can be effected by many things – driving style, engine tune and health, probably have the most likely effect.

Climate and elevation – ambient air temperature, relative humidity, and elevation can significantly affect MPG.

You obviously do not understand how that engine works.

The ECU and sensors have to function properly and the engine has to be highly tuned in order to get maximum gas mileage.

Why would you expect to get good or even decent gas mileage when you have a huge exhaust leak and critical feedback sensors are not even hooked up!!

How are you calculating the gas mileage?

What is the elevation and route and miles used to calculate the MPG - flat land, up hill down hill, freeway, in town?

What brand of gas are you buying?

What is the octane rating?

What oil viscosity are you running?

Are you using any oil or gasoline additives?

What gear ratio are the ring & pinions?

What size tires are you running?

Did you check the odometer calibration?

How many miles on this engine?

When was the last time this engine was tuned?

When was the last time the valve lash was checked/adjusted?

Have you ever done a compression check?

What do the spark plugs look like?

Driving your truck like you are on a limited tight budget and gas is $10 a gallon will improve your gas mileage.

Gnarls.

[aaron63]

Gnarls, that was a thing of beauty.  Beer on me when ever we shall meet.


Sent from my iPhone using Tapatalk

[Gnarly4X]

Gnarls, that was a thing of beauty.  Beer on me when ever we shall meet.


Sent from my iPhone using Tapatalk

Thank you, aaron63! 

If you buy the beer, I will buy the pizza!! 

Gnarls. 

[MrFatEggs [OP]]

I fixed everything besides the temp sensor and it is getting 13-14 mpg which I'm thinking is still bad. I'm right at sea level, the engine is rebuilt and has 160 compression in each cylinder, spark plugs look perfect, I'm running 31" tires with the stock drivetrain. I have never had the engine tuned, but I have the timing and valve lash spot on. I'm also using 10w30 oil. I'm hoping that hooking up the temp sensor will help my gas mileage. I looked for the wire the other day but I'm going to probably have to trace it from the ecu.

Trying to analyze gas mileage over the internet is like sniffing flowers through your butt.

Gas mileage can be effected by many things – driving style, engine tune and health, probably have the most likely effect.

Climate and elevation – ambient air temperature, relative humidity, and elevation can significantly affect MPG.

You obviously do not understand how that engine works.

The ECU and sensors have to function properly and the engine has to be highly tuned in order to get maximum gas mileage.

Why would you expect to get good or even decent gas mileage when you have a huge exhaust leak and critical feedback sensors are not even hooked up!!

How are you calculating the gas mileage?

What is the elevation and route and miles used to calculate the MPG - flat land, up hill down hill, freeway, in town?

What brand of gas are you buying?

What is the octane rating?

What oil viscosity are you running?

Are you using any oil or gasoline additives?

What gear ratio are the ring & pinions?

What size tires are you running?

Did you check the odometer calibration?

How many miles on this engine?

When was the last time this engine was tuned?

When was the last time the valve lash was checked/adjusted?

Have you ever done a compression check?

What do the spark plugs look like?

Driving your truck like you are on a limited tight budget and gas is $10 a gallon will improve your gas mileage.

Gnarls.

[Gnarly4X]

I fixed everything besides the temp sensor and it is getting 13-14 mpg which I'm thinking is still bad. I'm right at sea level, the engine is rebuilt and has 160 compression in each cylinder, spark plugs look perfect, I'm running 31" tires with the stock drivetrain. I have never had the engine tuned, but I have the timing and valve lash spot on. I'm also using 10w30 oil. I'm hoping that hooking up the temp sensor will help my gas mileage. I looked for the wire the other day but I'm going to probably have to trace it from the ecu.

Which temperature sensor?

Gnarls.

[redneckcustoms13]

I'm at sea level. My 3rz gets 14.

[MrFatEggs [OP]]

The temp sensor that tells the ecu when it's warmed up, without it I think it's squirting out of the cold start injector the whole time?

Which temperature sensor?

Gnarls.

[Gillesdetrail]

The ECT sensor (engine coolant temperature) plays a big part in fuel economy. Now the ecu thinks the engine is much cooler than it is, so it is sending a lot more fuel than the engine needs, to compensate. With the sensor disconected, there is a pre-set value temperature sent to the ecu and it is usually as cold as the sensor can read (on some cars). I'd get that fixed asap because it can also be bad for your piston rings, as the engine sends more fuel, it can contaminate or wash the oil on your piston walls which causes more friction. The correct spark plugs, gap and timing also plays a big part in performance and fuel economy.

[Gnarly4X]

I'm at sea level. My 3rz gets 14.

OOOUCH! 

Gnarls.

[Gnarly4X]

I fixed everything besides the temp sensor and it is getting 13-14 mpg which I'm thinking is still bad. I'm right at sea level, the engine is rebuilt and has 160 compression in each cylinder, spark plugs look perfect, I'm running 31" tires with the stock drivetrain. I have never had the engine tuned, but I have the timing and valve lash spot on. I'm also using 10w30 oil. I'm hoping that hooking up the temp sensor will help my gas mileage. I looked for the wire the other day but I'm going to probably have to trace it from the ecu.

OK M.. you are on the right track. 

Gnarls.

[redneckcustoms13]

OOOUCH! 

Gnarls.

Nothing does well here. My 06 tacoma with 1gr got 18 on stock tires.

[Gnarly4X]

The ECT sensor (engine coolant temperature) plays a big part in fuel economy. Now the ecu thinks the engine is much cooler than it is, so it is sending a lot more fuel than the engine needs, to compensate. With the sensor disconected, there is a pre-set value temperature sent to the ecu and it is usually as cold as the sensor can read (on some cars). I'd get that fixed asap because it can also be bad for your piston rings, as the engine sends more fuel, it can contaminate or wash the oil on your piston walls which causes more friction. The correct spark plugs, gap and timing also plays a big part in performance and fuel economy.

Before getting deep into weeds with the EFI system on 22RE, there are actually two temperature sensors – 1 is the Water Thermo Sensor and other is in the AFM – the Intake Air Thermo Sensor.

There are a number of sensors and ECU data used to monitor, control, and adjust the air-fuel mixture.  Any number of  out-of–spec data or mechanical functions will affect fuel efficiency.

At this point, I would want to get the water temp sensor working and then go from there.  Once all the primary sensors have been tested and the O2 sensor is working properly, I would disconnect the battery for 30 minutes and see if the ECU can make any adjustments to readings.

Gnarls.

[Gnarly4X]

The temp sensor that tells the ecu when it's warmed up, without it I think it's squirting out of the cold start injector the whole time?

There are two methods the 22RE uses to correct AFR - EC (enrichment correction) - that's what MammaECU uses,   and AD (auxiliary devices) - those do not involve the ECU.  There are two auxiliary devices - the Cold Start Injector and the Air Valve (Idle Air Control Valve).

Fuel flow and injectors can affect the gas mileage - that gets into another discussion.

Gnarls.

[gnob]

This thread is kind of a train wreck.

[Snowtoy]

The temp sensor that tells the ecu when it's warmed up, without it I think it's squirting out of the cold start injector the whole time?

The Cold Start Timer Switch operates the CS injector, not the coolant temp sensor.  The coolant temp sensor tells the ecu when the engine is at operating temp, w/it unplugged, the ecu will stay in "warm-up" mode ignoring all other sensors, when the one failed in my 3.0 last year, it got about 8-10mpg's.

I'm hoping that hooking up the temp sensor will help my gas mileage. I looked for the wire the other day but I'm going to probably have to trace it from the ecu.

If the location is the same for the 22ret as the re, it should be a green sensor next to a black one, by the t-stat.

[300k]

This thread is kind of a train wreck.

This is what happens. You guys are testing the limits and bounds. Let's just stick to carburetors where it's safe?

[Gnarly4X]

This is what happens. You guys are testing the limits and bounds. Let's just stick to carburetors where it's safe?

If it's a train a train wreck, you should have gotten off the at the last stop. 

And... if carbs were the answer, H8PVMNT would not be spending half his life here!! 

"testing the limits and bounds" is about 90% of ALL automotive history in it's evolution. 

Here, we are simply "testing". 

Gnarls. 

[Gnarly4X]

This thread is kind of a train wreck.

Is this your first "train wreck"?... Have you been on any other train wrecks in your last 536 posts?

Gnarls. 

[Gnarly4X]

The Cold Start Timer Switch operates the CS injector, not the coolant temp sensor.

Hmmm... yes, BUT the duration of the fuel injected by the Cold Start Injector is determined by the coolant temperature, which is sensed by the Water Thermo Sensor.

The coolant temp sensor tells the ecu when the engine is at operating temp, w/it unplugged, the ecu will stay in "warm-up" mode ignoring all other sensors, when the one failed in my 3.0 last year, it got about 8-10mpg's.

Correct.

The coolant temp sensor and the time switch can be tested with an Volt/Ohm meter.

Gnarls.