rover 75 v6 2.5 engine won't start - no spark

[fabian]

Hi there,

A few days ago, my car stop on the roadside with the problem of engine no start. I thought it was the battery issue. After towing back to my home, I tried to recharge the battery to the full capacity, then the engine started again (not a smooth start, I had to fire the engine 3 times). But only once, the next days, it won't start again. I realise that I'm not getting a spark when starting the engine (the engine turns but does not fire).

After did some research, I thought it might be the problem of Crankshaft Pulse Sensor. I got a new one and replaced today, but still the same. BTW, I also got a new Cam Sensor replaced last year.

I have followed some guides to test if I got good sensors. I can see the needle of rev counter is rise a little from the off position when firing the engine. (not sure if this is a correct test).

Can anyone tell what is the possible problem that engine is not getting a spark? what I should test next?

Thx

[SD1too]

Originally Posted by fabian

I realise that I'm not getting a spark when starting the engine (the engine turns but does not fire).

Hello Yu chang li,

Have you actually removed a sparking plug and observed it during cranking? If not, you've made an unsafe assumption. Low fuel pressure can cause non-starting and that is more likely due to the common fault of your filter canister loosening. Search the forum for "fuel filter syndrome", "FFS" and "orange clip" and you'll find everything you need to know.

Originally Posted by fabian

I thought it might be the problem of Crankshaft Pulse Sensor. I got a new one and replaced today, but still the same.

We could have saved you time and money there. There's a simple test involving no tools to check that the crankshaft position sensor is working. I've posted many times about this which a search or a question would have revealed.

Simon

[fabian]

Originally Posted by SD1too

Hello Yu chang li,

Have you actually removed a sparking plug and observed it during cranking? If not, you've made an unsafe assumption. Low fuel pressure can cause non-starting and that is more likely due to the common fault of your filter canister loosening. Search the forum for "fuel filter syndrome", "FFS" and "orange clip" and you'll find everything you need to know.


We could have saved you time and money there. There's a simple test involving no tools to check that the crankshaft position sensor is working. I've posted many times about this which a search or a question would have revealed.

Simon

Hi Simon,

Thanks for your reply. You have always been very helpful and supportive.

The car was tested by the roadside assistant using their tools and tester before towing. They did remove a sparking plug as u said and observed it during cranking. So pretty sure that the problem is caused by not getting a spark.

I didn't see the post about how to test the crankshaft position sensor is working until replaced the sensor. So I did the test with the new sensor to see if I bought a good one. (Check rev counter is rising a little from the off position when firing the engine.)

Now, I pretty sure that I have the working cam and crankshaft sensors installed but the engine is still no getting spark. What I feel that is something is loose or not connected properly.

any idea??

Richard

[SD1too]

Originally Posted by fabian

They did remove a sparking plug as u said and observed it during cranking. So pretty sure that the problem is caused by not getting a spark.

Hi Richard,

OK, so the fault could be a failed ignition coil on that cylinder only or a complete loss of ignition. A diagnostic tool may give you a quick answer otherwise repeat the spark test on a different plug.

Simon

[fabian]

Originally Posted by SD1too

Hi Richard,

OK, so the fault could be a failed ignition coil on that cylinder only or a complete loss of ignition. A diagnostic tool may give you a quick answer otherwise repeat the spark test on a different plug.

Simon

Hi Simon,

I have just tested the 3 front coils, none of them gets power when the engine is turning. I feel that it may not be coil problem, I remember that I have changed all of them 3 years ago when the engine had a misfire.

and suggestion??

Richard

[SD1too]

Originally Posted by fabian

I have just tested the 3 front coils, none of them gets power when the engine is turning.

That's very strange. Can you tell me exactly how you tested them please Richard?

Simon

[BigRuss]

It could be a power supply problem to the immobilizer
Check the fuses in the passenger compartment fusebox from memory it's a 5amp fuse that can cause that problem.
Had this problem a couple of times now on customers cars

The other possibility of course is the immobiliser itself especially if your car has a sunroof.

Russ

[T-Cut]

Hello fablan,
From my read through of your symptoms, I'd suggest checking Fuse 3 in the engine fusebox. This protects the cam sensor circuit.

If Fuse 3 is OK, you should confirm that the fuel pump runs at ignition on. Get an assistant to turn the ignition on while you listen for the pump buzzing. Put your ear to the fuel tank filler hole. The pump should run for a few seconds, then stop.

If the pump runs OK, then check for fuel filter separation. If there isn't a retaining clip fitted to the filter module cap, you really need to fix that.

Good luck.

TC

[fabian]

Originally Posted by T-Cut

Hello fablan,
From my read through of your symptoms, I'd suggest checking Fuse 3 in the engine fusebox. This protects the cam sensor circuit.

If Fuse 3 is OK, you should confirm that the fuel pump runs at ignition on. Get an assistant to turn the ignition on while you listen for the pump buzzing. Put your ear to the fuel tank filler hole. The pump should run for a few seconds, then stop.

If the pump runs OK, then check for fuel filter separation. If there isn't a retaining clip fitted to the filter module cap, you really need to fix that.

Good luck.

TC

Hi TC,

Fuse 3 is OK. to make sure I have replaced it with the spare one. The fuel pump is also Ok. It runs at ignition on, I can hear the pump is buzzing from the fuel tank filler hole

[fabian]

Originally Posted by BigRuss

It could be a power supply problem to the immobilizer
Check the fuses in the passenger compartment fusebox from memory it's a 5amp fuse that can cause that problem.
Had this problem a couple of times now on customers cars

The other possibility of course is the immobiliser itself especially if your car has a sunroof.

Russ

I have replaced the fuses (it's number 7, 5amp) with the spare one, but still the same.

I don't think it's the immobilizer problem, as it works just fine. I can lock/unlock the car and turn the engine on, but the engine is just not ignited.