Hi everyone,
I am getting very desperate at this stage. I have spent close to $1500 trying to chase down and fix this issue, it has been to 3 different mechanics of whom have no clue or were just unable to fix it with the suggested parts being replaced. Pretty reluctant to approach any more mechanics given the history with the issue (feeling very defeated at the moment).
2002 1FZ-FE Dual fuel petrol
My car, every time I drive it, will be very hesitant when I first start driving it, and will only really take off if I have my foot to the floor, which it then takes off like a rocket. Gear changes are pretty rough too. When I accelerate, the vacuum goes up really high, but the engine just wont really go. The engine has a deeper note to it when it is 'struggling' or 'hesitating. It does not jerk at all. (I have a little dial on my dash, use to be dual fuel). If I let it idle to temp, the issue still occurs, and the issue only seems to go away after I have flogged the car a few times, or after 5-10 minutes of driving, and then it starts driving OKish. When I start it of a morning and take off in first gear with my foot down, once it shifts into second the momentum gets pulled back substantially, as if there is not enough power following through into second. Issue is present whilst in neutral, too - Have a video of me revving it in neutral and doing its thing: New video by Alexander Burgess - https://photos.app.goo.gl/fotr5bb1UwpL3sxa7 . The car drives like it is just coming off the showroom floor on LPG - Drives perfect, full of power and no hesitation what-so-ever.
My LPH is pretty good, it is about 17L/100 if its just highway, and about 21-22L/100 with mixed city and highway driving. Sometimes when I start it in the morning, a couple of drops of liquid come out the exhaust pipe (Might be normal since the 1fz fe has no O2 sensors to trim fuel).
Also blows white smoke on start up, valve stem seals are on their way out.
The car has back-fired on previous owned, so there is a slight crack in the top of the airbox, and the lid is only held down by 1 clip. I am not suspecting this as the issue as the car runs perfectly fine on LPG. I have also tried spraying "Start ya bastard" through the engine bay to try and identify and vacuum hose leaks/cracks or splits anywhere in the intake system, the engine did not react to the spray what-so-ever. I am also not suspect it is the valve clearance as it ran perfect on LPG.
I don't believe its an issue with the drivetrain, or auto box as it all runs perfect on LPG, has full power through gear changes and no sign of hesitation/sluggishness.
I hooked up a fuel pressure gauge after the fuel filter, started the car and it comfortably sat at 42 PSI (Factory spec is 38-44). It quickly flicked up and back down to 42 when I accelerated, however, once I turned the car off the pressure dropped to near 0 in about 15 seconds (not sure if it was my gauge connection as I was just holding it together). Ran fine whilst holding it with my hands, though. The throttle body plate looks very clean looking down the intake manifold.
I bought it 8 months ago, it was previously 100% ran on gas and rarely on petrol. I initially changed the fuel filter, which was brown, and soon after I had the tank professionally cleaned (had some rust) and also the injectors taken off the car, flow tested, serviced and put back in. After this, parts that have been replaced are:
*FPR (Car seemed to perform pretty good for 3 days, then went back to its old ways)
*Various vacuum hoses and clamps
*Intake pipe to manifold is brand new
*Replaced fuel filter a second time
*Fuel pump (I don't have a sub tank to test as it has a LPG tank in place)
*Brand new spark plugs
*HT Leads are very new (inspected and in near perfect condition)
*TPS
*Wet/Dry compression test on all 6 cylinders indicate they are all within 5 PSI of factory spec.
*I've also run 98 petrol through it a couple of times, along with injector cleaner no improvement
I have started removing the LPG side of things to see if is something to do with the LPG controlling the petrol side of things, including:
*Removed the LPG timing relay which was screwed to the firewall
*Re-spliced the red wire in the engine bay harness near the firewall
*Re-spliced and disconnected the LPG stuff from the 3 ignition coils
*Heater hose was leaking at the T intersection to the firewall, so the mixer is completely disconnected from the coolant hoses as well as power now.
*Removed the gas line from the mixer to the intake pipe, intake pipe is brand new.
As I said before, it ran like a brand new car, very smooth and fast with very smooth gear changes on LPG - All of this only happens on petrol.
Any help would be greatly appreciated... Thank you for your time.
I am getting very desperate at this stage. I have spent close to $1500 trying to chase down and fix this issue, it has been to 3 different mechanics of whom have no clue or were just unable to fix it with the suggested parts being replaced. Pretty reluctant to approach any more mechanics given the history with the issue (feeling very defeated at the moment).
2002 1FZ-FE Dual fuel petrol
My car, every time I drive it, will be very hesitant when I first start driving it, and will only really take off if I have my foot to the floor, which it then takes off like a rocket. Gear changes are pretty rough too. When I accelerate, the vacuum goes up really high, but the engine just wont really go. The engine has a deeper note to it when it is 'struggling' or 'hesitating. It does not jerk at all. (I have a little dial on my dash, use to be dual fuel). If I let it idle to temp, the issue still occurs, and the issue only seems to go away after I have flogged the car a few times, or after 5-10 minutes of driving, and then it starts driving OKish. When I start it of a morning and take off in first gear with my foot down, once it shifts into second the momentum gets pulled back substantially, as if there is not enough power following through into second. Issue is present whilst in neutral, too - Have a video of me revving it in neutral and doing its thing: New video by Alexander Burgess - https://photos.app.goo.gl/fotr5bb1UwpL3sxa7 . The car drives like it is just coming off the showroom floor on LPG - Drives perfect, full of power and no hesitation what-so-ever.
My LPH is pretty good, it is about 17L/100 if its just highway, and about 21-22L/100 with mixed city and highway driving. Sometimes when I start it in the morning, a couple of drops of liquid come out the exhaust pipe (Might be normal since the 1fz fe has no O2 sensors to trim fuel).
Also blows white smoke on start up, valve stem seals are on their way out.
The car has back-fired on previous owned, so there is a slight crack in the top of the airbox, and the lid is only held down by 1 clip. I am not suspecting this as the issue as the car runs perfectly fine on LPG. I have also tried spraying "Start ya bastard" through the engine bay to try and identify and vacuum hose leaks/cracks or splits anywhere in the intake system, the engine did not react to the spray what-so-ever. I am also not suspect it is the valve clearance as it ran perfect on LPG.
I don't believe its an issue with the drivetrain, or auto box as it all runs perfect on LPG, has full power through gear changes and no sign of hesitation/sluggishness.
I hooked up a fuel pressure gauge after the fuel filter, started the car and it comfortably sat at 42 PSI (Factory spec is 38-44). It quickly flicked up and back down to 42 when I accelerated, however, once I turned the car off the pressure dropped to near 0 in about 15 seconds (not sure if it was my gauge connection as I was just holding it together). Ran fine whilst holding it with my hands, though. The throttle body plate looks very clean looking down the intake manifold.
I bought it 8 months ago, it was previously 100% ran on gas and rarely on petrol. I initially changed the fuel filter, which was brown, and soon after I had the tank professionally cleaned (had some rust) and also the injectors taken off the car, flow tested, serviced and put back in. After this, parts that have been replaced are:
*FPR (Car seemed to perform pretty good for 3 days, then went back to its old ways)
*Various vacuum hoses and clamps
*Intake pipe to manifold is brand new
*Replaced fuel filter a second time
*Fuel pump (I don't have a sub tank to test as it has a LPG tank in place)
*Brand new spark plugs
*HT Leads are very new (inspected and in near perfect condition)
*TPS
*Wet/Dry compression test on all 6 cylinders indicate they are all within 5 PSI of factory spec.
*I've also run 98 petrol through it a couple of times, along with injector cleaner no improvement
I have started removing the LPG side of things to see if is something to do with the LPG controlling the petrol side of things, including:
*Removed the LPG timing relay which was screwed to the firewall
*Re-spliced the red wire in the engine bay harness near the firewall
*Re-spliced and disconnected the LPG stuff from the 3 ignition coils
*Heater hose was leaking at the T intersection to the firewall, so the mixer is completely disconnected from the coolant hoses as well as power now.
*Removed the gas line from the mixer to the intake pipe, intake pipe is brand new.
As I said before, it ran like a brand new car, very smooth and fast with very smooth gear changes on LPG - All of this only happens on petrol.
Any help would be greatly appreciated... Thank you for your time.
