Toyota Kr42

Sampharis · August 27, 2008

Dear All

I have recently purchsed a KR42 (2001) /GL with 117k in odo meter. It is fitted with a Lovato venturi type autogas unit and no records about how many kilometers it has been run on autogas since the conversion. It was imported to Sri Lanka at around 95k odo reading. My problem is, when it is driven around 1km in the morning (on petrol around 60kmph), it drops its pulling power and does not respond to the gas pedal. At this stage the engine shakes very badly and this cause the entire vehicle to shake and vibrate. If the fuel is changed over to gas it becomes fine. This happens almost every day. Please help me to come out of this problem. Am I running to a major engine repair?

Thanks in advance

Harindraj77 · August 27, 2008

Dear All
I have recently purchsed a KR42 (2001) /GL with 117k in odo meter. It is fitted with a Lovato venturi type autogas unit and no records about how many kilometers it has been run on autogas since the conversion. It was imported to Sri Lanka at around 95k odo reading. My problem is, when it is driven around 1km in the morning (on petrol around 60kmph), it drops its pulling power and does not respond to the gas pedal. At this stage the engine shakes very badly and this cause the entire vehicle to shake and vibrate. If the fuel is changed over to gas it becomes fine. This happens almost every day. Please help me to come out of this problem. Am I running to a major engine repair?

Thanks in advance

Hey... are U running on Petrol mode or gas mode when U get this issue?

On EFI GAS conversions, there is an automatic switch from petrol to gas and if the both petrol and gas switch is not happening smoothly, this jerk can happen for few seconds as engine starts to Miss when both GAP and Petrol mix together...

If U get the same issue when U run only on petrol mode, then it's to do with your EFI tune up..

Sampharis · August 27, 2008

Hey... are U running on Petrol mode or gas mode when U get this issue?
On EFI GAS conversions, there is an automatic switch from petrol to gas and if the both petrol and gas switch is not happening smoothly, this jerk can happen for few seconds as engine starts to Miss when both GAP and Petrol mix together...

If U get the same issue when U run only on petrol mode, then it's to do with your EFI tune up..

thankx for swift response. I normally run on petrol until the engine heats up, around 1km or so before switch in to gas. The problem arises during that period but not while the cahnging over takes place. If I run my first kilometer on gas, same behavior is observed with loud backfiring.

Nilantha · August 27, 2008

Dear All
I have recently purchsed a KR42 (2001) /GL with 117k in odo meter. It is fitted with a Lovato venturi type autogas unit and no records about how many kilometers it has been run on autogas since the conversion. It was imported to Sri Lanka at around 95k odo reading. My problem is, when it is driven around 1km in the morning (on petrol around 60kmph), it drops its pulling power and does not respond to the gas pedal. At this stage the engine shakes very badly and this cause the entire vehicle to shake and vibrate. If the fuel is changed over to gas it becomes fine. This happens almost every day. Please help me to come out of this problem. Am I running to a major engine repair?

Thanks in advance

According to my experience you better to do engine tune up. First tune the engine to run from petrol smoothly after that u have to clean and tune up the gas unit.

I think you problem comes up when you are changing from petrol to gas.

This type of things happen when mixed petrol and the gas. So when u change from petrol to gas first you have to drive until all the petrol finish that come to carburetor. After that u have to switch on the gas.

I think this happen bcos u r new person to gas converted vehicle. I think you will soon become familiar with gas converted vehicle.

The Don · August 27, 2008

According to my experience you better to do engine tune up. First tune the engine to run from petrol smoothly after that u have to clean and tune up the gas unit.
I think you problem comes up when you are changing from petrol to gas.

This type of things happen when mixed petrol and the gas. So when u change from petrol to gas first you have to drive until all the petrol finish that come to carburetor. After that u have to switch on the gas.

I think this happen bcos u r new person to gas converted vehicle. I think you will soon become familiar with gas converted vehicle.

I think sampharis has been very clear in stating this problem does not occur at the change over stage, and manifests itself irrespective of which fuel is used to start the vehicle.

If the fuel is changed over to gas it becomes fine.

I just cannot even guess how switching over to the other fuel solves this problem ! because if the problem is with the engine it should not get fixed by switching over to a different fuel. Most tuning related issues manifest when the engine is cold, not when it warms up !

I think thus the issue is with the Autogas unit, and probably the unit that manages the switch over. Like you said it might be mixing petrol with Gas ! and when the switch over is initiated, the problem fixes itself !

I think this vehicle is EFI.

Perhaps you should take your vehicle to the company who did the conversion and ask them to have a look at it.

Sampharis · September 1, 2008

I think sampharis has been very clear in stating this problem does not occur at the change over stage, and manifests itself irrespective of which fuel is used to start the vehicle.
I just cannot even guess how switching over to the other fuel solves this problem ! because if the problem is with the engine it should not get fixed by switching over to a different fuel. Most tuning related issues manifest when the engine is cold, not when it warms up !

Yes you are correct. Today I noticed the problem even after changing over to the gas (I mean after the changeing over was successfully completed) Seems that it goes away as I rev-up the engine few times. Since the engine is usually rev-up for the fuel switch over to take place (automatically) it was not aparent previously as I think.

I think thus the issue is with the Autogas unit, and probably the unit that manages the switch over. Like you said it might be mixing petrol with Gas ! and when the switch over is initiated, the problem fixes itself !
I think this vehicle is EFI.

Perhaps you should take your vehicle to the company who did the conversion and ask them to have a look at it.

I went to the place where the gas conversion was done and they found no problem with their unit. I spoke to the Agent about the problem and they told that they don't recommend gas conversions for this vehicle and dont take such vehicles for engine repairs and I am about to ruin my engine!! :unsure: .

Any way I will do the engine tuneup and see.

Will some injector cleaner additives help?

Is it not good to run on gas as agent says??

What is meant by "Engine tune up" for EFI engines???

Thanks

The Don · September 1, 2008

Yes you are correct. Today I noticed the problem even after changing over to the gas (I mean after the changeing over was successfully completed) Seems that it goes away as I rev-up the engine few times. Since the engine is usually rev-up for the fuel switch over to take place (automatically) it was not aparent previously as I think.
I went to the place where the gas conversion was done and they found no problem with their unit. I spoke to the Agent about the problem and they told that they don't recommend gas conversions for this vehicle and dont take such vehicles for engine repairs and I am about to ruin my engine!! .

Any way I will do the engine tuneup and see.

Will some injector cleaner additives help?

Is it not good to run on gas as agent says??

What is meant by "Engine tune up" for EFI engines???

Thanks

Well, not all engines cope very well with Gast Conversions, and it tends to affect the lubrication of the engine and various rubbers seals etc of the fuel injection system. Bottom line is your engine is probably going to require a bit more servicing running auto gas compared to petrol.

The agent as you can understand is a representative of the manufacturer and thus will only recommend what the manufacturer recommends. The engine in your vehicle was not designed to run auto gas and thus the agent will not support you when problems occur with such an engine. It is because they have no expertise on resulting problems and also because they have no obligation to do so since you have modified the engine beyond a specification they support.

I do not think you should use any sort of additive at the moment, and do need to concentrate on sorting out the problem properly.

I do think the issue is one of Petrol and Gas mixing together at the turn over process. What you could try is to get the auto gas people to bypass the switch over unit and try to start and run the engine on petrol alone (as in plug the petrol line directly to the EFI unit). If the engine works fine, then the problem is definitely with the Auto gas unit installed by that company.