1FZ-FE running rich! Plz help me haha (2 Viewers)

[geddes33]

G’day!

Aussie here, so I have a 100 series… BUT it’s got a 1FZ-FE (with a manual behind it), given my question is engine related only I’ve been informed I’m better off on the 80 series forum than the 100!

So, here’s my conundrum, I’m running rich.. still.

I’ve changed/tested;

- plugs and oil,

- changed the MAP sensor and vac hoses as the old one seemed to have an internal fault (3.5v across active and ground at idle instead of 5v, yet 5v out of the plug when unplugged).

- Intake temp sensor measured within spec, but haven’t ruled out putting a new one in to eliminate the chances.

- intake pipe work back to factory.

Usually I start with testing/changing the O2 sensor on EFI cars, but this doesn’t have one.


Things I’ve noticed;

- high idle (especially when cold - told this is sort of normal), but I can pull up at the lights, not completely cold and idle at 1600. Way too high. Other times more like 900.

- some run on after turning car off.

- fairly strong fuel smell.

- high usage of fuel approx 20 l/100km, I know I can get this down lower given the fuel smell, I’m not towing and I drive like an elderly grandma going to church.


Where im at;

My thoughts are leaking injectors maybe?

I’m gearing up to get the injectors tested and rebuilt if needed, and a new regulator and all new intake gaskets as a last resort, I’m going to test for a leak first with the old brake clean test.

The car did have gas for about 10 years before I bought it, I’m wondering if they retune or something for gas? Maybe retard timing, I know timing being off can cause run on and fuel usage? What’s standard timing?

I’ve also heard people say the Charcoal canister can cause issues, how would I test this?

Honestly open to anything and hoping for help! My usual hobby is cars with carbies so I can set them up how I want. But I’m here to learn!

Sorry for the essay. That’s all I can think of for now.

Cheers in advance!

 

[NeverFinis]

I assume gas = LPG.

I know nothing about LPG conversions...

How did the LPG system integrated with the engine?

Any codes from the ECM?

Does your check engine light work?

Can you pull the tune and look at it, like an LS engine?

Yes, I think looking for vacuum leaks is a good idea. The rubber intake is known to crack.

Could they have swapped the injectors? I mean, is there a LPG system that uses the injectors? IDK.

Might be time to get the injectors cleaned and inspected anyway.

As far as the charcoal canister, is the gas tank pressurized when you first take the cap off when fueling up?

 

[geddes33]

I assume gas = LPG.

I know nothing about LPG conversions...

How did the LPG system integrated with the engine?

Any codes from the ECM?

Does your check engine light work?

Can you pull the tune and look at it, like an LS engine?

Yes, I think looking for vacuum leaks is a good idea. The rubber intake is known to crack.

Could they have swapped the injectors? I mean, is there a LPG system that uses the injectors? IDK.

Might be time to get the injectors cleaned and inspected anyway.

As far as the charcoal canister, is the gas tank pressurized when you first take the cap off when fueling up?

Yes! Sorry gas=LPG in Australia and we call gas, petrol that was my bad! Haha

I’m not entirely sure how it integrated, it came with the LPG system removed, I only know it had one because of the compliance plate that we have to have by law over here. I know it doesn’t use the injectors, from other systems I’ve seen I believe it has a plate in front of the throttle body.

Check engine light I assume works, it lights up on accessories haha then goes away.

Not sure as far as tunes, that’s going to be my last option taking it to a tuner and getting it checked.

I have found the OBD2 port, but my reader won’t read it. Maybe I need some pre OBD2 protocol scanner?

That’s interesting about the charcoal canister, I haven’t noticed the fuel tank pressurised. Should it be? Haha

Cheers!

 

[NeverFinis]

Your scanner should be able to connect via OBD2, which became standard on a FZJ80s about 1995.

A US 100 series should would have a working OBDII port but who knows what Toyota does in other markets.

You might have to find a EWD (electrical wiring diagram) for your model and check to see if there is a OBD2 circuit.

Yes, if the check engine lights up, then it is working. Some people disable to it to hide issues.

A pressurized gas tank can be evidence of a failed charcoal canister.

Is there evidence of a piggy back ECM in the engine compartment?

Is your MAF or MAP sensor in the intake or is it near the air filter? I think you have a MAP sensor on the intake.

If it is in the intake, I am not sure how air leaks before the intake would change fuel enrichment.

Are you using a OEM Map sensor or a 3rd party brand?

 

[geddes33]

Your scanner should be able to connect via OBD2, which became standard on a FZJ80s about 1995.

A US 100 series should would have a working OBDII port but who knows what Toyota does in other markets.

You might have to find a EWD (electrical wiring diagram) for your model and check to see if there is a OBD2 circuit.

Yes, if the check engine lights up, then it is working. Some people disable to it to hide issues.

A pressurized gas tank can be evidence of a failed charcoal canister.

Is there evidence of a piggy back ECM in the engine compartment?

Is your MAF or MAP sensor in the intake or is it near the air filter? I think you have a MAP sensor on the intake.

If it is in the intake, I am not sure how air leaks before the intake would change fuel enrichment.

Are you using a OEM Map sensor or a 3rd party brand?

There is my other problem, it was design rule in USA for OBD2 ports but not Australia in 2002, so I have one but it doesn’t have the protocol to talk to scanners MINT! I know. Haha apparently Toyota don’t go nuts on installing things they don’t have to.

I’ll check for a piggyback this afternoon. I did notice a plug under the throttle body with a dongle thing in it. But I have no way of knowing what it actually does.

MAP is in the intake manifold and I bought OEM DENSO, **** cheap sensors, you end up chasing your tail. Haha good question though!

I need to find a set of the service books.

 

[robnicko]

being a 100 series with a 1fzfe im presuming it has coil packs and not a distributor? if so then timing is not adjustable as its set by the ECU unlike the 80-series with a distributor

if the LPG was removed make sure all of the intake tubing is put back to stock OEM 1st

Have a check of the fuel pressure regulator - unplug the small vacuum hose from it and see if any fuel spills out, if so then its diaphragm is leaking and your getting full / excessive fuel

post some pics of the engine bay if you can

 

[geddes33]

being a 100 series with a 1fzfe im presuming it has coil packs and not a distributor? if so then timing is not adjustable as its set by the ECU unlike the 80-series with a distributor

if the LPG was removed make sure all of the intake tubing is put back to stock OEM 1st

Have a check of the fuel pressure regulator - unplug the small vacuum hose from it and see if any fuel spills out, if so then its diaphragm is leaking and your getting full / excessive fuel

post some pics of the engine bay if you can

Yep! Coil packs, can the stock ECU be tuned at all?

I put all original intake back on when I bought it as it had a s***ty pod filter right above the exhaust manifold only thing I didn’t replace back to factory was the resonator cans? I machined up some acetyl bungs for those holes, figured they just change intake noise. Other thing the intake had that was weird was like a blade fan shaped piece in the hose part that goes through the fender? Figure that’s the whistle I can hear under load.

Put all new vac hoses on the fuel regulator when I changed the MAP sensor, double checked just then and no leaking fuel. Is there anyway the diaphragm could be stuck open or failing in another way? That would definitely fit my issues I’ve been having. That is one of the things I want to change, but I also don’t want to throw money at my guesswork haha.

Have taken some pics! Hope you like, sorry the steering is on the right hand side! I also have an American 75 f truck, I kept that left hand drive.

I’ve circled in blue on one picture the plug thing I found, yet to find what it does.

Thanks again for everyone’s input, I’m finding this really helpful, cheers!

 

[MissahPapaJ]

G’day!

Aussie here, so I have a 100 series… BUT it’s got a 1FZ-FE (with a manual behind it), given my question is engine related only I’ve been informed I’m better off on the 80 series forum than the 100!

So, here’s my conundrum, I’m running rich.. still.

I’ve changed/tested;

- plugs and oil,

- changed the MAP sensor and vac hoses as the old one seemed to have an internal fault (3.5v across active and ground at idle instead of 5v, yet 5v out of the plug when unplugged).

- Intake temp sensor measured within spec, but haven’t ruled out putting a new one in to eliminate the chances.

- intake pipe work back to factory.

Usually I start with testing/changing the O2 sensor on EFI cars, but this doesn’t have one.


Things I’ve noticed;

- high idle (especially when cold - told this is sort of normal), but I can pull up at the lights, not completely cold and idle at 1600. Way too high. Other times more like 900.

- some run on after turning car off.

- fairly strong fuel smell.

- high usage of fuel approx 20 l/100km, I know I can get this down lower given the fuel smell, I’m not towing and I drive like an elderly grandma going to church.


Where im at;

My thoughts are leaking injectors maybe?

I’m gearing up to get the injectors tested and rebuilt if needed, and a new regulator and all new intake gaskets as a last resort, I’m going to test for a leak first with the old brake clean test.

The car did have gas for about 10 years before I bought it, I’m wondering if they retune or something for gas? Maybe retard timing, I know timing being off can cause run on and fuel usage? What’s standard timing?

I’ve also heard people say the Charcoal canister can cause issues, how would I test this?

Honestly open to anything and hoping for help! My usual hobby is cars with carbies so I can set them up how I want. But I’m here to learn!

Sorry for the essay. That’s all I can think of for now.

Cheers

 

[MissahPapaJ]

G’day!

Aussie here, so I have a 100 series… BUT it’s got a 1FZ-FE (with a manual behind it), given my question is engine related only I’ve been informed I’m better off on the 80 series forum than the 100!

So, here’s my conundrum, I’m running rich.. still.

I’ve changed/tested;

- plugs and oil,

- changed the MAP sensor and vac hoses as the old one seemed to have an internal fault (3.5v across active and ground at idle instead of 5v, yet 5v out of the plug when unplugged).

- Intake temp sensor measured within spec, but haven’t ruled out putting a new one in to eliminate the chances.

- intake pipe work back to factory.

Usually I start with testing/changing the O2 sensor on EFI cars, but this doesn’t have one.


Things I’ve noticed;

- high idle (especially when cold - told this is sort of normal), but I can pull up at the lights, not completely cold and idle at 1600. Way too high. Other times more like 900.

- some run on after turning car off.

- fairly strong fuel smell.

- high usage of fuel approx 20 l/100km, I know I can get this down lower given the fuel smell, I’m not towing and I drive like an elderly grandma going to church.


Where im at;

My thoughts are leaking injectors maybe?

I’m gearing up to get the injectors tested and rebuilt if needed, and a new regulator and all new intake gaskets as a last resort, I’m going to test for a leak first with the old brake clean test.

The car did have gas for about 10 years before I bought it, I’m wondering if they retune or something for gas? Maybe retard timing, I know timing being off can cause run on and fuel usage? What’s standard timing?

I’ve also heard people say the Charcoal canister can cause issues, how would I test this?

Honestly open to anything and hoping for help! My usual hobby is cars with carbies so I can set them up how I want. But I’m here to learn!

Sorry for the essay. That’s all I can think of for now.

Cheers in advance!

You can pinch or plug hose from fuel tank to canister ( leave gas cap loose and tank less than 70% and see if it helps and go from there, I think for us USA types it might be hard to get great advice cause we don’t have 80/100 series in that configuration. But as for myself I’d whore myself behind a IHOP during brunch for an engine combo out of one of those to swap into an early 80 series state side.
Is this thing 0BD1/2? Or is it the old Toyota under hood connector?
Can you monitor any data?
When all else fails if you think it’s a leaking injector you could always use an automotive stethoscope and see if there’s a slight noise difference between them. If so or not sometimes gently tapping them with a ratchet extension and seeing if there’s a change in performance ( usually you can hear the change, possibly momentary )
Unrelated but I’ve had Jeeps with similar set ups as I assume you have ( OBD2 though ) have a lean condition where O2 sensors and computer decided it had ran lean for long enough on the short term fuel side and made the vehicle go full rich. So the code it set was a vehicle running rich bank 1 and 2. No codes at all for a lean condition.

What OBD system you guys running out there on that vintage 100?

 

[NeverFinis]

Neat seeing the newer 1FZ-FE. Is that the fuel filter on the passenger fender? Is that the stock location for it?

I find it more possible that the ECM has a tune since you mentioned that a non-OEM air intake was removed.

MAP sensors are calibrated for stock intakes.

Can you get another ECM and swap it to test?

 

[geddes33]

You can pinch or plug hose from fuel tank to canister ( leave gas cap loose and tank less than 70% and see if it helps and go from there, I think for us USA types it might be hard to get great advice cause we don’t have 80/100 series in that configuration. But as for myself I’d whore myself behind a IHOP during brunch for an engine combo out of one of those to swap into an early 80 series state side.
Is this thing 0BD1/2? Or is it the old Toyota under hood connector?
Can you monitor any data?
When all else fails if you think it’s a leaking injector you could always use an automotive stethoscope and see if there’s a slight noise difference between them. If so or not sometimes gently tapping them with a ratchet extension and seeing if there’s a change in performance ( usually you can hear the change, possibly momentary )
Unrelated but I’ve had Jeeps with similar set ups as I assume you have ( OBD2 though ) have a lean condition where O2 sensors and computer decided it had ran lean for long enough on the short term fuel side and made the vehicle go full rich. So the code it set was a vehicle running rich bank 1 and 2. No codes at all for a lean condition.

What OBD system you guys running out there on that vintage 100?

I’ll try that with the charcoal canister, it’s supposed to have OBD2, it has a plug but won’t read. I believe Toyota didn’t put the capability in the Aussie ones because our government didn’t require it! Sadly lol

I believe some of the wreckers here send complete motors to the states.

I have the OG diagnostic port in the engine bay too.

 

[geddes33]

Neat seeing the newer 1FZ-FE. Is that the fuel filter on the passenger fender? Is that the stock location for it?

I find it more possible that the ECM has a tune since you mentioned that a non-OEM air intake was removed.

MAP sensors are calibrated for stock intakes.

Can you get another ECM and swap it to test?

Yes! It is, same as our Hilux’s.

I don’t have access to a different ECM, however if I can’t fix it myself I’ll take it to a tuner.

LPG has a cut down intake so I figure they used the short pipe just being cheap. That’s why i put all the OG stuff back on.

 

[Dragos80]

I have chased this problem on my 80 for years. Took it to several mechanics. I had a lot of parts replaced plus timing done twice.
The last mechanic figured out it was the MAF sensor.
Replaced and it ran worse. Sent it back and got another one. It did not run. Got the old MAF sensor in and it ran as before. Ordered yet another one (the third one) and it ran rough.

He decided to clean the original one as best as he could and send back all the new ones which were defective for some reason.

It now runs fine.

It's worth a shot if you can test the MAF sensor or have someone to test it for you to see if it runs within the normal parameters.

 

[robnicko]

there are a couple of items missing before the throttle body on the intake tube that are blanked off in your pics.
See the pic below as there are two canister type plastic items that need to be in place if wanting it to be back to standard. You may want to source these and install so the air flow is what the ECU and sensors are looking for.

 

[geddes33]

I have chased this problem on my 80 for years. Took it to several mechanics. I had a lot of parts replaced plus timing done twice.
The last mechanic figured out it was the MAF sensor.
Replaced and it ran worse. Sent it back and got another one. It did not run. Got the old MAF sensor in and it ran as before. Ordered yet another one (the third one) and it ran rough.

He decided to clean the original one as best as he could and send back all the new ones which were defective for some reason.

It now runs fine.

It's worth a shot if you can test the MAF sensor or have someone to test it for you to see if it runs within the normal parameters.

No MAF sadly.

 

[geddes33]

there are a couple of items missing before the throttle body on the intake tube that are blanked off in your pics.
See the pic below as there are two canister type plastic items that need to be in place if wanting it to be back to standard. You may want to source these and install so the air flow is what the ECU and sensors are looking for.



View attachment 3954213

Yep, they’re $120 each here (aftermarket, probably 300 each from Toyota) in Aus, a lot of money to pay for resonators to remove some intake sound. I don’t believe it to be these, I plugged the holes with acetyl bungs I machined up - my local mechanic gave it a tick of approval upon roadworthy. I currently have the intake off searching for vac leaks. So I’m going to change the ECU coolant plug at the same time. I am curious as to if it is sending the correct temperatures to the ECU. I wonder if it’s telling my ecu that the engine is constantly cold. I also got the injectors cleaned and tested while the intake is off, gave the IAC assembly a good clean out too. Fingers crossed.

 

[geddes33]

Update.

No difference, although it does look prettier now. Still *seems* to be running rich, idle still sh*tty, high and lagging behind. Thinking maybe it needs a new IAC, it runs nicer with the IAC unplugged, revs drop down, thinking maybe the motor in the IAC is shagged.

I did test the coolant sensor at set temperatures of 15c, 40c, 65c, 85c and 100c and the resistance figures were spot on in range. So I put that back in. As mentioned earlier in the post, new denso MAP, now eliminated a vacuum leak. I’m thinking IAC and fuel reg for good measure.

 

[geddes33]

Double points to anyone who can help me with what the f**k this is?! I’m still extremely curious. Anyone got factory wiring schematics?

 

[NeverFinis]

Can you take a closer picture of that electrical connector, end on? It looks like a diode end plug.

Speaking of diodes, do you know that you might have a Idle-Up Diode? Check into that and its fuse.

Do you even have an IAC given that you have an electric throttle?

I think the big thing is to check for codes. I know you tried to read the OBDII port but I think it is key now. The FSM has a checklist for idle issues, which is based on engine codes. In the US, there are many automotive parts stores that will read the OBDII port for free. Perhaps something is available like that in Aus?

IMHO, those resonators were for NVH and weren't required for this issue.