1fz-fe dual fuel system question

[99fzj105]

Hello again everyone,

I was hoping someone could help me figure out a potential cause of lack of power in my 1fz-fe. The car was modified for a dual fuel system a long time ago m, lpg & petrol. Since I bought the vehicle the Lpg side of things has never worked so I just run it on petrol. Which I’m fine with, I’m not a big fan of lpg. Question is, could all the lpg components that are installed in the car be hindering the performance of engine when running on petrol? Rich mixture setup? Items for lpg that are attached to the air intake just next to the manifold? It feels like it lacks power and I’m wondering if the old lpg system is possibly causing this or at least contributing - in comparison of getting the lpg system uninstalled which is my next step. Any advice welcome thanks in advance. I have also turned the Lpg tank off to stop feeding any gas (if any) to the motor via the on/off screw switch on the tank itself.

 

[99fzj105]

Also should mention the vehicle has recently had all new leads, plugs, fuel filter and air filter

 

[joshAUST]

Also should mention the vehicle has recently had all new leads, plugs, fuel filter and air filter

No real answer here but a suggestion.
If you have the older style vacuum type LPG setup, with the big mixer - dish - thingy between the air filter and the inlet manifold, from what I've read that could be restricting the airflow when on petrol.
The easiest option to test it would be to bypass that piece altogether and run a pipe directly from the air filter to the intake manifold and see if that makes a difference to performance.

With the gas turned off, you should not have to remove any of the gas system to test if that is the issue, just move it out of the way.
You can buy aftermarket air intake pipes online for around $30 or so AUD from that online auction site, or get those concertina adjustable pipes to test it with.
eg, but pricey: Memorex Air Induction Pipe - Black, 76mm - https://www.supercheapauto.com.au/p/memorex-memorex-air-induction-pipe---black-76mm/122206.html SHOULD suit, but check diameters...

(This item had a bad review on the above page, re quality, however the person who left that review also included a photo of their setup - also on gas, but with a much larger mixer?).
If, after bypassing the gas, performance improves, then you can either just bypass the gas altogether, or look at perhaps another mixer that allows greater airflow when on petrol.

I too, am in exactly the same boat as you, but with a FZJ105.
Dual fuel, only runs on petrol, and lacking power.
I picked it up yesterday.
My engine is a 1FZ-FE.
The mixer is an Impco ca225m-3-2.
The vaporiser, the thing to the RH side of the intake manifold, is labeled L.P.G. Spares Model LPG-H420.
From looking around, the vaporiser should be suitable for engines up to 350 HP, so should provide more than enough power for the 1FZ-FE.
Hence why I suspect the mixer.

If I get a chance to try out the above temporary gas bypass on my car before you, I'll try to update the result.
In the meantime, any advice to @99fzj105 and myself as well appreciated.

 

[mudgudgeon]

No real answer here but a suggestion.
If you have the older style vacuum type LPG setup, with the big mixer - dish - thingy between the air filter and the inlet manifold, from what I've read that could be restricting the airflow when on petrol.
The easiest option to test it would be to bypass that piece altogether and run a pipe directly from the air filter to the intake manifold and see if that makes a difference to performance.

With the gas turned off, you should not have to remove any of the gas system to test if that is the issue, just move it out of the way.
You can buy aftermarket air intake pipes online for around $30 or so AUD from that online auction site, or get those concertina adjustable pipes to test it with.
eg, but pricey: Memorex Air Induction Pipe - Black, 76mm - https://www.supercheapauto.com.au/p/memorex-memorex-air-induction-pipe---black-76mm/122206.html SHOULD suit, but check diameters...

(This item had a bad review on the above page, re quality, however the person who left that review also included a photo of their setup - also on gas, but with a much larger mixer?).
If, after bypassing the gas, performance improves, then you can either just bypass the gas altogether, or look at perhaps another mixer that allows greater airflow when on petrol.

I too, am in exactly the same boat as you, but with a FZJ105.
Dual fuel, only runs on petrol, and lacking power.
I picked it up yesterday.
My engine is a 1FZ-FE.
The mixer is an Impco ca225m-3-2.
The vaporiser, the thing to the RH side of the intake manifold, is labeled L.P.G. Spares Model LPG-H420.
From looking around, the vaporiser should be suitable for engines up to 350 HP, so should provide more than enough power for the 1FZ-FE.
Hence why I suspect the mixer.

If I get a chance to try out the above temporary gas bypass on my car before you, I'll try to update the result.
In the meantime, any advice to @99fzj105 and myself as well appreciated.

At those prices, just buy a new genuine OEM intake pipe from partsouq.com
will cost less than $100 shipped in a few days, and will fit right straight away

 

[robnicko]

My 1fz-fe 80 runs dual fuel using an impco 225 and B2 Aussie converter - originally installed in late 99 and have replaced the converter a couple of times as the coolant seals wear out on them.

I do not believe the LPG components affect the engine performance when running on Petrol however that's if their not faulty or restricted in some way.
The Impco mixer would be the main culprit as does reduce the air intake size slightly but then returns to normal size after it however in my vehicle do not notice any difference in performance. That being said in slow traffic when running on LPG it does feel like more low down torque initially and seems more snappy.

A good friend of mine has a 100 series with a 1fzfe and LPG (same setup as I have ) and he always complained of lack of power, high fuel usage etc both petrol & lpg after the LPG install. The only thing i saw different in his setup was that he had coil packs as opposed to a distributor like the 80 series have and there was a large plastic chamber of sorts in the intake that was removed as part of the LPG installation - he always suspected that had something to do with it.
He afterwards installed a snorkel and that made it worse so he ditched it all and went back to standard but had to retain the snorkel cause he cut a hole in the guard !

are you able to provide some pics of the setup / engine bay?
does your car have 02 sensors?
has it ever backfired through the intake?

 

[99fzj105]

Thanks for all the informative replies, yes I believe it had backfired when the old owner had it because I had to replace the air box as when I purchased the vehicle the bottom of the air box was split in about 4 different places which I assume would be a backfire outcome. My vehicle is actually an fzj105 lol I’m not sure why I posted in the 80s tech section. I think one of my other threads on here was moved to the 80s section for some reason so I just automatically posted in the 80s tech section. But yes I will look into bypassing the mixer ring for the lpg. I mean I know they are heavy vehicles but she just feels gutless :/ unless I’m really putting my foot to the floor and even then it feels like I’m trying to pull a steam train behind me.

 

[99fzj105]

My mixer round thing also says lpg spares, I will take photos for you tomorrow and we can compare specs

 

[99fzj105]

Here is one I took a few weeks ago

 

[99fzj105]

Also - people have made me really weary about touching anything to do with the gas system. Like it’s going to blow up the vehicle or something. Can anyone make sense of that? Do you need a specialist to remove lpg items on a dual fuel system?

 

[99fzj105]

Pics

 

[robnicko]

yes, you are supposed to be a licensed LPG fitter to remove the system and work on it
LPG is under immense pressure

looking at the pic's its similar to mine in that the converter is in the same spot however the mixer setup is different. Mine is just the impco in line between the air filter and intake

if it has had a backfire to the point where the air box cracked there is a very good chance the MAF is damaged and probably the reason for sluggish performance

 

[joshAUST]

99fzj105
Your gas system doesn't seem to be fully connected - at least on the vaporiser.
On mine, the two front pipes connect to the radiator to run warm water through the unit to vaporise the gas.
Yours are not connected to anything going from your last photo.

The vaporiser itself looks identical to my, also not working, lol, one.
Your mixer looks about three times as long as my one however.

I had heard that backfires can damage the mixer - I think the diaphragm gets damaged, and I guess that could block the air flow in when on petrol.
I'd undo the two ring clamps - the one on the airbox and the one on the inlet manifold, and move all of that back to make room for a replacement non-gas intake pipe and give it a test.

If you don't ever want gas anyway, I'd probably get the OEM part as mudgudgeon suggested.
I'm not too sure how much work it would be to fully remove the gas permanently, as you'd have to remove the mixer, the vaporiser, and the associated electricals - which are pretty minimal, and the gas tank, filler cap and line.
A lot of the work would have been plugging the radiator lines, which you wouldn't need to do, as yours aren't connected anyway.

 

[99fzj105]

99fzj105
Your gas system doesn't seem to be fully connected - at least on the vaporiser.
On mine, the two front pipes connect to the radiator to run warm water through the unit to vaporise the gas.
Yours are not connected to anything going from your last photo.

The vaporiser itself looks identical to my, also not working, lol, one.
Your mixer looks about three times as long as my one however.

I had heard that backfires can damage the mixer - I think the diaphragm gets damaged, and I guess that could block the air flow in when on petrol.
I'd undo the two ring clamps - the one on the airbox and the one on the inlet manifold, and move all of that back to make room for a replacement non-gas intake pipe and give it a test.

If you don't ever want gas anyway, I'd probably get the OEM part as mudgudgeon suggested.
I'm not too sure how much work it would be to fully remove the gas permanently, as you'd have to remove the mixer, the vaporiser, and the associated electricals - which are pretty minimal, and the gas tank, filler cap and line.
A lot of the work would have been plugging the radiator lines, which you wouldn't need to do, as yours aren't connected anyway.

Thanks for replies. Yes I recently had a lot of work done on the vehicle and had a new radiator installed along with heaps of other things including a new head for the motor and I told the guy the gas wasn’t working and I don’t intend to use it and when I got it back those 2 hoses had been disconnected and put in a cardboard box on my back seat of the car. I will do the bypass and see how it goes. I will also replace the MAF sensor and air temp sensor. I just found them both after scratching my head for a minute.

 

[joshAUST]

An update on mine, but no solution to date.
I bypassed the Impco mixer with a bit of pipe, and the car still runs like crap...
While I had my mixer was out, I disassembled it and checked that the diaphram was undamaged.
It seemed to be in perfect condition.

I think I may also have an issue with crap in the fuel tank with mine, and/or fuel pump issue.
Have you had any luck with yours?
Re the MAF and air temp sensor, does the 1FZ-Fe on a FZJ105 actually have a MAF sensor?
I thought, but could be wrong, that it didn't.
I assume the air temp sensor is the one on the air filter box?
On my old UZJ100, that was the location of the MAF sensor.

 

[99fzj105]

An update on mine, but no solution to date.
I bypassed the Impco mixer with a bit of pipe, and the car still runs like crap...
While I had my mixer was out, I disassembled it and checked that the diaphram was undamaged.
It seemed to be in perfect condition.

I think I may also have an issue with crap in the fuel tank with mine, and/or fuel pump issue.
Have you had any luck with yours?
Re the MAF and air temp sensor, does the 1FZ-Fe on a FZJ105 actually have a MAF sensor?
I thought, but could be wrong, that it didn't.
I assume the air temp sensor is the one on the air filter box?
On my old UZJ100, that was the location of the MAF sensor.

Hey mate yes I’ve had success with mine in regards to getting it to run a lot smoother, so basically yes the fzj105 does have a MAF sensor it’s attached to the inlet manifold. I replaced that and nothing changed so I bought a few bottles of fuel injector cleaner and ran those through a few tanks of petrol and it started to run better but still felt rough especially when accelerating, idling it was rough too, so I did some research on what sensors can have an affect of how the engine runs and came across the ‘crank angle sensor’ which for the fzj105 is directly under the engine in the middle closest to the radiator in front of the oil pan. I read that a crank angle sensor that is beginning to fail can cause all sorts of issues specifically rough idling, poor Accelerating, hard gear shifts and poor fuel economy and can also make it hard to start the engine due to the failing sensor sending incorrect information to the onboard computer. So I forked out the $200 for a new sensor and what do you know, all my ‘rough’ issues are now gone. So it’s worth checking that sensor if not just replacing it for peace of mind. I read that over time this sensor in particular wears out due to being exposed to the engine internals for so long. Let me know how you go, I can say I didn’t expect it to be that sensor but it definitely fixed the issues.

Also I haven’t tried the bypass of the mixer yet but that is on my list of things to do

Definitely worth running at least 2 full bottles of either penrite injector cleaner or penrite complete system cleaner for good measure and it help clean any crap out of the fuel system. I was never a believer in that sort of stuff I thought it was just gimmicks to make $$ but it does actually do well. I also read that the genuine Toyota injectors are far superior to any other on the market for the 1fz’s and that it’s well worth the time to run a cleaning solution through them as 98% of the time the injectors are still good as gold they have just got build up of crud from all fuel over the years.

 

[joshAUST]

Thanks for the update @99fzj105
That's great news!
Glad to hear you've got it sorted.
I might go down that path as well.
Was that price for a genuine part, or an aftermarket?
Would you have the link for it?
In the meantime I will try some injector cleaner, and probably some Ethanol based petrol to try to absorb and burn any water that may be in the tank.
While its running very rough, both idling, and under load, it became noticeably worse, including having multiple stalls, when it was running low on fuel. Low, but still above the empty line that is. It always started again immediately when I put it in park and restarted it.
After adding $50 in fuel, it started running better, still rough, but not stalling, so I suspect there is water, or rust, or other crap, in the tank.
I'll try to update when I get a chance.

 

[99fzj105]

Thanks for the update @99fzj105
That's great news!
Glad to hear you've got it sorted.
I might go down that path as well.
Was that price for a genuine part, or an aftermarket?
Would you have the link for it?
In the meantime I will try some injector cleaner, and probably some Ethanol based petrol to try to absorb and burn any water that may be in the tank.
While its running very rough, both idling, and under load, it became noticeably worse, including having multiple stalls, when it was running low on fuel. Low, but still above the empty line that is. It always started again immediately when I put it in park and restarted it.
After adding $50 in fuel, it started running better, still rough, but not stalling, so I suspect there is water, or rust, or other crap, in the tank.
I'll try to update when I get a chance.

Yes definitely update as you can I’m putting money on your crank angle sensor is failing, stalling is one main symptom of a failing crank sensor. I forgot to put that in last post, but basically that Particular sensor will cause an array of issues. This is the link to the sensor I bought online , it is in fact a genuine Toyota replacement. Hence the price tag.

Crank angle sensor for Toyota Landcruiser FZJ75 FZJ78 FZJ80 FZJ105 4.5L 1FZ-FE 1 | eBay

Find many great new & used options and get the best deals for Crank angle sensor for Toyota Landcruiser FZJ75 FZJ78 FZJ80 FZJ105 4.5L 1FZ-FE 1 at the best online prices at eBay!

www.ebay.com.au

It’s a very easy sensor to replace, only 3 12mm bolts holding the protection plate Surrounding the sensor and then once that’s off there is just 2 10mm bolts holding the sensor, pop the old one out and bolt the new one in and connect the electrical connector on the other end.

 

[99fzj105]

Here is a photo of the sensor location (best photo I could find online)

 

[joshAUST]

Awesome!
Thanks so much.
Yes, reading around, and watching a few videos, I'd say you're on the money.
The symptoms all match.
I won't get a chance to work on it for a while, but I will update once I replace it.
Thanks also for the location of it... I was looking.

 

[99fzj105]

Awesome!
Thanks so much.
Yes, reading around, and watching a few videos, I'd say you're on the money.
The symptoms all match.
I won't get a chance to work on it for a while, but I will update once I replace it.
Thanks also for the location of it... I was looking.

No worries mate good luck, best wishes. And look
Forward to hearing the outcome