1fz-fe dual fuel system question (1 Viewer)

[joshAUST]

Well, nearly a year later, an update, FWIW.
I've spent the last year driving the car, changing the fuel filter every 3 months or so and just driving it slow, with less acceleration.
I haven't yet replaced the tanks, but am in the process of ordering parts, as I am going to replace both the fuel pumps, gaskets, etc.
I have found that you can rinse out a fuel filter, largely by blowing backwards through it, and a fair bit of crap came out, and then reused it once.
Not as good as a new filter, but might save someone in a difficult situation.

You've probably already replaced the fuel filter by now, but just in case, and for anyone else wondering, its very easy to replace the fuel filter.
On the output side of the filter, just squeeze the two white clips at the base of the hose and jiggle the hose up and it should disconnect.
Then, while holding the filter on the RH side with a socket, use another socket to loosen the fuel line nut.
Do not strip or damage that!
Then remove the two bolts holding the fuel filter bracket onto the chassis, then remove the filter.
Transfer the bracket to the new filter, finger tighten the fuel line bolt on loosely, then do up the two bolts, then tighten the fuel line bolt, then press on the output line until it clicks into place on the other end of the filter. Start the engine and test for leaks.

However, I have more serious problems.
The valves are burnt - according to a mechanic I took it to.
Requires the head to be overhauled, or replaced, with hardened valves if I want to continue using LPG as well as petrol.
I'm sure the PO must have been aware of it - that's a lesson to get a compression test done prior to purchase.

So, I think tanks installed first, then off to get the head rebuilt or replaced, and then I might do something about the hole/s in the exhaust....

Hope yours is going well @99fzj105.

 

[99fzj105]

Well, nearly a year later, an update, FWIW.
I've spent the last year driving the car, changing the fuel filter every 3 months or so and just driving it slow, with less acceleration.
I haven't yet replaced the tanks, but am in the process of ordering parts, as I am going to replace both the fuel pumps, gaskets, etc.
I have found that you can rinse out a fuel filter, largely by blowing backwards through it, and a fair bit of crap came out, and then reused it once.
Not as good as a new filter, but might save someone in a difficult situation.

You've probably already replaced the fuel filter by now, but just in case, and for anyone else wondering, its very easy to replace the fuel filter.
On the output side of the filter, just squeeze the two white clips at the base of the hose and jiggle the hose up and it should disconnect.
Then, while holding the filter on the RH side with a socket, use another socket to loosen the fuel line nut.
Do not strip or damage that!
Then remove the two bolts holding the fuel filter bracket onto the chassis, then remove the filter.
Transfer the bracket to the new filter, finger tighten the fuel line bolt on loosely, then do up the two bolts, then tighten the fuel line bolt, then press on the output line until it clicks into place on the other end of the filter. Start the engine and test for leaks.

However, I have more serious problems.
The valves are burnt - according to a mechanic I took it to.
Requires the head to be overhauled, or replaced, with hardened valves if I want to continue using LPG as well as petrol.
I'm sure the PO must have been aware of it - that's a lesson to get a compression test done prior to purchase.

So, I think tanks installed first, then off to get the head rebuilt or replaced, and then I might do something about the hole/s in the exhaust....

Hope yours is going well @99fzj105.

Hi Josh thanks for your update! The last year has gone very quickly. I’m glad to hear your still sorting out your Landcruiser. Toyota do make great vehicles, unfortunately if previous owners do not keep up proper and regular servicing and maintenance that’s what let’s a Toyota down.

I have had a lot of work done on mine, it basically has not stopped since we last spoke. Someone said to me the other day, ‘that things gonna send you bankrupt’, I laughed and agreed. None the less it is running well. I have managed to get majority of the issues I previously had under control.

You should post some photos of your beast Josh so we can see her/him

 

[joshAUST]

Hi Josh thanks for your update! The last year has gone very quickly. I’m glad to hear your still sorting out your Landcruiser. Toyota do make great vehicles, unfortunately if previous owners do not keep up proper and regular servicing and maintenance that’s what let’s a Toyota down.

I have had a lot of work done on mine, it basically has not stopped since we last spoke. Someone said to me the other day, ‘that things gonna send you bankrupt’, I laughed and agreed. None the less it is running well. I have managed to get majority of the issues I previously had under control.

You should post some photos of your beast Josh so we can see her/him

Back again, about a year later, lol.

I'm glad to hear your vehicle running well.

Turns out the valves in mine aren't stuffed, the mechanic just assumed they were! grr...

I had the car start to run really roughly, turned out one of the knock sensors gave out, 200KM from home.
I was able to very slowly crawl back home.
No MIL codes, surprisingly.

However, after a different mechanic replaced both knock sensors with non-genuine ones, it ran better, but still ran poorly.
He basically gave up on it after a few days.
So I drove it home, running on only 4 cylinders I reckon, as it was my only vehicle.

I decided to go through it, one step at a time, starting with plugs and leads... and quickly found that cylinder no.2 wasn't firing, no change when the lead was disconnected.
When I swapped leads, the problem followed the lead, so I knew it was faulty.
I replaced them with Bosch ones - the cheaper ones with the big rubber plugs that are meant for distributors, not the ones for coils at thrice the price.
They were a bit tight to get onto the coils, but I succeeded.

After replacing them, the car seemed a heap better, but still not perfect.
Having a look at the fuel injector electrical connectors, I discovered most had broken locking clips, and number 5 cylinder was not firing at all.
So, I sprayed all of the plugs with contact cleaner, and then put a cable tie around the electrical clip and the injectors themselves, locking them into place.
All of a sudden, it was like a new car, with a heap more power.

I suspect it had been running on only 4-5 cylinders since I bought it.
So, I'm really happy, but I don't really trust mechanics anymore.
The $50 investment in a pressure test kit is well worth it.
Happy driving.

 

[AussieHJCruza]

You'll get on much better learning to do your own work

 

[petegangies]

Back again, about a year later, lol.

I'm glad to hear your vehicle running well.

Turns out the valves in mine aren't stuffed, the mechanic just assumed they were! grr...

I had the car start to run really roughly, turned out one of the knock sensors gave out, 200KM from home.
I was able to very slowly crawl back home.
No MIL codes, surprisingly.

However, after a different mechanic replaced both knock sensors with non-genuine ones, it ran better, but still ran poorly.
He basically gave up on it after a few days.
So I drove it home, running on only 4 cylinders I reckon, as it was my only vehicle.

I decided to go through it, one step at a time, starting with plugs and leads... and quickly found that cylinder no.2 wasn't firing, no change when the lead was disconnected.
When I swapped leads, the problem followed the lead, so I knew it was faulty.
I replaced them with Bosch ones - the cheaper ones with the big rubber plugs that are meant for distributors, not the ones for coils at thrice the price.
They were a bit tight to get onto the coils, but I succeeded.

After replacing them, the car seemed a heap better, but still not perfect.
Having a look at the fuel injector electrical connectors, I discovered most had broken locking clips, and number 5 cylinder was not firing at all.
So, I sprayed all of the plugs with contact cleaner, and then put a cable tie around the electrical clip and the injectors themselves, locking them into place.
All of a sudden, it was like a new car, with a heap more power.

I suspect it had been running on only 4-5 cylinders since I bought it.
So, I'm really happy, but I don't really trust mechanics anymore.
The $50 investment in a pressure test kit is well worth it.
Happy driving.

how did you discover/determine the knock sensors needed replacing with no MIL code?

 

[joshAUST]

how did you discover/determine the knock sensors needed replacing with no MIL code?

Hi.
Sorry, my mistake, I meant no check engine light!
When I jumpered the diagnostic port in the engine bay, it did indicate code 12 - with the green cruise control LED flashing the sequence 1, then 2.

The symptoms I was getting were as follows, for what its worth.
I had just driven from Hobart to Lauceston (around 200KMs), and about a km from my accomodation it started running really poorly.
I limped it to the car park.
The next day, I changed the fuel filtes - as I have been having ongoing issues with rust, and assumed it must be that, but it wasn't.
On the drive back, I could barely accelerate - it was like there was some resistance, so I didn't want to accelerate to much, as it seemed to run worse the more I pushed the pedal.
Going up some steeper hills, the car literally slowed to a crawl - sometimes walking pace, so I'd put on the hazards and creep down the emergency stopping lane.
Once over the hill, the car would rapidly speed up, up to 100kms, no worries, and then on the flat I was only able to maintain about 70-80 KPH.
It was a long, stressful drive.
If I tried to accelerate, it seemed to run worse, and felt like something might break.

 

[petegangies]

Hi.
Sorry, my mistake, I meant no check engine light!
When I jumpered the diagnostic port in the engine bay, it did indicate code 12 - with the green cruise control LED flashing the sequence 1, then 2.

The symptoms I was getting were as follows, for what its worth.
I had just driven from Hobart to Lauceston (around 200KMs), and about a km from my accomodation it started running really poorly.
I limped it to the car park.
The next day, I changed the fuel filtes - as I have been having ongoing issues with rust, and assumed it must be that, but it wasn't.
On the drive back, I could barely accelerate - it was like there was some resistance, so I didn't want to accelerate to much, as it seemed to run worse the more I pushed the pedal.
Going up some steeper hills, the car literally slowed to a crawl - sometimes walking pace, so I'd put on the hazards and creep down the emergency stopping lane.
Once over the hill, the car would rapidly speed up, up to 100kms, no worries, and then on the flat I was only able to maintain about 70-80 KPH.
It was a long, stressful drive.
If I tried to accelerate, it seemed to run worse, and felt like something might break.

Mine is bogging down like that. No check engine light and no codes. Have replaced a tonne of stuff. Extremely frustrating. Havent looked at my knock sensors.

 

[joshAUST]

Sorry to hear Petegangies.
I know the possibilities can seem endless, but I'd recommend running the engine until its warm, then start disconnecting spark plug leads, to see if there is any change, whch would indicate an issue with either the plug, lead, or injector for that cylinder,

Plus compression test each cylinder with a kit from Ebay, around $50 AUD.
My number 6, near the firewall, was lower than the rest, but still not a major issue, for now.
Check also the fuel injector leads, and cable tie them ijnto place if their locking clips are broken or seem loose.
.

 

[petegangies]

Sorry to hear Petegangies.
I know the possibilities can seem endless, but I'd recommend running the engine until its warm, then start disconnecting spark plug leads, to see if there is any change, whch would indicate an issue with either the plug, lead, or injector for that cylinder,

Plus compression test each cylinder with a kit from Ebay, around $50 AUD.
My number 6, near the firewall, was lower than the rest, but still not a major issue, for now.
Check also the fuel injector leads, and cable tie them ijnto place if their locking clips are broken or seem loose.
.

has new plugs and leads (I've done the plugs twice, just to be extra sure). All my injector clips are on and unbroken. I can hear every injector pulsing/clicking during idle by using a long screw driver and listening. I dont think it's an ignition issue as it runs fine on gas, just not petrol. Had an on-car injector clean done (directly into the rail), and it made no difference either.

The fuel pump is being replaced next week even though we're not convinced my original is playing up, but we're at the point that there's not much left hasn't been replaced. The mechanic is also going to look at the connection where the LPG system is spliced in to the injectors. Will also test fuel pump relay and transistor. We are both suspecting this is going to be a wiring/electrical issue, as the car had a partial loom replacement. No engine lights or codes. Very weird.

 

[joshAUST]

has new plugs and leads (I've done the plugs twice, just to be extra sure). All my injector clips are on and unbroken. I can hear every injector pulsing/clicking during idle by using a long screw driver and listening. I dont think it's an ignition issue as it runs fine on gas, just not petrol. Had an on-car injector clean done (directly into the rail), and it made no difference either.

The fuel pump is being replaced next week even though we're not convinced my original is playing up, but we're at the point that there's not much left hasn't been replaced. The mechanic is also going to look at the connection where the LPG system is spliced in to the injectors. Will also test fuel pump relay and transistor. We are both suspecting this is going to be a wiring/electrical issue, as the car had a partial loom replacement. No engine lights or codes. Very weird.

Hmm.
So you have jumped the te1 and e1 or whatever pins in the diagnostic plug near the air filter, and you still get no codes on either the check engine light, or, on my FZJ105R at least, on the green Cruise control light?
If no codes, I would not expect it would be a knock sensor.
Perhaps have a look at the connectors to the knock sensors, although they are a bit awkward to get to, especially I guess with a LPG system fitted as well.

Remember that there are two fuel pumps, one in each tank, so if it does it on both I'd doubt it would be both pumps.

Have you replaced the fuel filter?
My tanks are rusty, so it gradually builds up in the fuel filter, and eventually causes the car to run really rough, and if I try to accellerate quickly, it will almost stall.
I also find it would starve for fuel near 110KPH..
Fairly easy to check, just remove the filter, and blow backwards through it into a rag or paper towel and have a look.
(It also makes mine drive much better for a while).

An outside, and unlikely one, is if the fuel tank cap breather is blocked, that could also cause fule starvation, and cause the car to accelerate badly... take it for a quick drive with the fuel tank cap loosened off to test it...

Have you replaced any other sensors?
I replaced the Crank Angle sensor, the Throttle Position sensor, the manifold absolute pressure sensor - and the filter thingy to that.
I also replaced the fuel pressure regulator, and, when it started pissing out petrol, the Fuel rail pressure damper.

Clean air filter and throttle body?

Again, if it runs fine on LPG, and just not on petrol, I doubt these other sensors would be the cause though.

On my FZJ105R, there is some control module, in the passenger footwell kick panel, that has a dial/potentiometer, that had LPG on one side, and petrol on the other...
I assume its doing something with the timing or something where you can perhaps favor running on LPG over petrol, or vice versa.
I've not played with mine, but if a PO has adjusted that, perhaps it could be worth looking at?
I'd record where the dial is first before playing with it.

Good luck with it, and let me know how you go.
If I think of anything else, I'll let you know.

 

[petegangies]

Hmm.
So you have jumped the te1 and e1 or whatever pins in the diagnostic plug near the air filter, and you still get no codes on either the check engine light, or, on my FZJ105R at least, on the green Cruise control light?
If no codes, I would not expect it would be a knock sensor.
Perhaps have a look at the connectors to the knock sensors, although they are a bit awkward to get to, especially I guess with a LPG system fitted as well.

Remember that there are two fuel pumps, one in each tank, so if it does it on both I'd doubt it would be both pumps.

Have you replaced the fuel filter?
My tanks are rusty, so it gradually builds up in the fuel filter, and eventually causes the car to run really rough, and if I try to accellerate quickly, it will almost stall.
I also find it would starve for fuel near 110KPH..
Fairly easy to check, just remove the filter, and blow backwards through it into a rag or paper towel and have a look.
(It also makes mine drive much better for a while).

An outside, and unlikely one, is if the fuel tank cap breather is blocked, that could also cause fule starvation, and cause the car to accelerate badly... take it for a quick drive with the fuel tank cap loosened off to test it...

Have you replaced any other sensors?
I replaced the Crank Angle sensor, the Throttle Position sensor, the manifold absolute pressure sensor - and the filter thingy to that.
I also replaced the fuel pressure regulator, and, when it started pissing out petrol, the Fuel rail pressure damper.

Clean air filter and throttle body?

Again, if it runs fine on LPG, and just not on petrol, I doubt these other sensors would be the cause though.

On my FZJ105R, there is some control module, in the passenger footwell kick panel, that has a dial/potentiometer, that had LPG on one side, and petrol on the other...
I assume its doing something with the timing or something where you can perhaps favor running on LPG over petrol, or vice versa.
I've not played with mine, but if a PO has adjusted that, perhaps it could be worth looking at?
I'd record where the dial is first before playing with it.

Good luck with it, and let me know how you go.
If I think of anything else, I'll let you know.

Yep, no codes. Have replaced fuel filter. Have tried loosened fuel cap, only sensor replaced was ECT. TPS was tested and adjusted (and checked twice). Throttle body and air filter both clean. My changeover settings are fine. I havent been running gas at all, just focusing on getting the petrol side running right.

Cheers
Pete