[tsk1979]

Yes, they changed Fuel pump and the pressure valve and lots of other components, nothing helped.
Right now the car is at service center, and they have lodged a complaint again with central TML, and they will guide by phone. If nothing works after all this, they will send an engineer from head office Gurgaon.

[Thomas8700]

forgot to mention! is the pressure control valve or metering unit. ( these are the two types of pressure valves involved in crdi, a third type is there CPC its a mix of both former mentioned valves.) checked? .

also since the surge is at idling, injection timing is most probably the culprit.
electronic causes. are as i mentioned in my earlier posts.

if possible check the rail pressure sensor. it might be sending wrong signal at idling?
have you ever used any kind of tuning box

did you check the cam and crank position sensor. check that also.

if any tech guy comes to the service center. then just tell him that at 0% ACC ped position , EPM module is probably giving interupt signal at wrong time or for more time than normal for the pre tdc injection some guys call it as pilot injections too.

anyways keep us posted.

[tsk1979]

Earlier rail pressure sensor had an error code, and after changing injectors that went away.
As for Cam sensor, thats an interesting angle, but there are no error codes in the system form any sensor now.
They checked the ignition timing, and thats correct.
Will keep you posted as updates comes.

[suman]

Originally Posted by Thomas8700

did you check the cam and crank position sensor. check that also.

Originally Posted by tsk1979

As for Cam sensor, thats an interesting angle, but there are no error codes in the system form any sensor now.

To the best of my knowledge, any issues with either of these will resulting in the vehicle not starting - it will not cause any surge in rpm.

[musicmanaman]

Tsk, one thing is for sure, I think you have gone through soo many issues with the Bull that I think now you are the most knowledgeable person regarding the Safari 2.2 in the forum.

[anupmathur]

Originally Posted by suman

To the best of my knowledge, any issues with either of these will resulting in the vehicle not starting - it will not cause any surge in rpm.

Suman, I think these sensors, or just one of them, would be responsible for giving the ECU feedback on actual rpm too.
An error (or delayed signal or whatever) could cause rpm to fluctuate.
It will not always be the case that an error will altogether prevent the engine from starting. That would be an extreme/catastrophic failure.

[tsk1979]

The rpm does not fluctuate all the time.
When I start her up in the morning, rpm keep fluctuating.
this goes away once engine is warm, even with AC on there is hardly any fluctuation.
Now when I drive at rpms above 2500rpm, and then come back to idle, for a few minutes the rpms keep fluctuating.
Without AC its very less, infact it lasts for few seconds and then its mostly stable, with slight fluctuations now and then.
AC on magnifies this.
If I have to demonstrate it to service center, all I have to do is rev her up to 4000 once, and once RPM needle comes back to idle speed its grrr grrr grrr for few minutes, and then it stabilizes.

The interesting thing is that whenever something like ECU/injector/washer etc., is changed, the problem goes way for 200-300kms after which ECU learns again how to dance.

I spoke to service center, they have lodged a complaint with TML on the website system dealers have and are awaiting reply

[theMAG]

Tan - sincere suggestion: if the vehicle is running smoothly and reliably otherwise, sweep this problem under the rug and enjoy the vehicle.

[Rahulk76]

Originally Posted by anupmathur

Suman, I think these sensors, or just one of them, would be responsible for giving the ECU feedback on actual rpm too.
An error (or delayed signal or whatever) could cause rpm to fluctuate.
It will not always be the case that an error will altogether prevent the engine from starting. That would be an extreme/catastrophic failure.

IMHO points to Crank Angel Sensor,
The crank angel sensor is fitted on the clutch housing. Can you have it cleaned and checked once ?

Crank Sensor is a magnetic field transducer and generates a voltage output propotional to the rate of change of the magnetic field near a "Missing tooth" configuration. It monitors the rotating speed (rpm), the position of the crankshaft / piston ans speed fluctuations of the engine and gives continuous feedback to the ECU. In other words it gives engine speed and piston position signal to the ECU. The sensor gap should be 1+-0.5mm & should be measured using feeler gauge.

[tsk1979]

Originally Posted by theMAG

Tan - sincere suggestion: if the vehicle is running smoothly and reliably otherwise, sweep this problem under the rug and enjoy the vehicle.

I have to go to Ladakh, thats why I am worried. What if it exposes some bigger problem at that altitude

Originally Posted by Rahulk76

IMHO points to Crank Angel Sensor,
The crank angel sensor is fitted on the clutch housing. Can you have it cleaned and checked once ?

I will ask workshop guys too look at that angle also!

[anupmathur]

Originally Posted by Rahulk76

IMHO points to Crank Angel Sensor,

You're right, Rahul.
The angle sensor also senses the rpm.

[suman]

Originally Posted by anupmathur

It will not always be the case that an error will altogether prevent the engine from starting. That would be an extreme/catastrophic failure.

Well, it will be the case for the cam sensor - it prevents the engine from starting if it senses that the cam is misaligned. That is the only purpose of its existence.

But yes, in the case of the crank sensor, it does monitor rpm as well. However, if excessive dust accumulates on it, it refuses to let the engine start.

[Rahulk76]

Originally Posted by anupmathur

You're right, Rahul.
The angle sensor also senses the rpm.

That information is straight from Manual, has to be right

[anupmathur]

Originally Posted by suman

Well, it will be the case for the cam sensor - it prevents the engine from starting if it senses that the cam is misaligned. That is the only purpose of its existence.

That means this sensor verifies the camshaft position with respect to the crankshaft.

Is there such a sensor in use? If this were the case the sensor would cut the engine in case of timing belt breakage too?

[Rahulk76]

Originally Posted by anupmathur

That means this sensor verifies the camshaft position with respect to the crankshaft.

Is there such a sensor in use? If this were the case the sensor would cut the engine in case of timing belt breakage too?

It wont let it start..It wont pitch in when it is already running would it. But by then the damage would already be done