Major Car Problem..Please help

[Tumie]

Guys, my car is giving me hell. Been 3 weeks now and I still dont know where the problem is coming from. This is the situation:
About 3 weeks ago she started giving me slight jerks while I was driving. It eventually got to a point where she would just cut in the middle of the road and stop moving all together. I'd have to wait, say maybe 2 minutes, crank her up again and off she goes. Took her to my mechanic and using the OPS and GT1 Diagnosis Computer, he picked up that Injector 1 was overflowing. Every other injector was pushing -0.1 to -.09. Injector 1 was sitting at 6! While we at it, we performed the Rail Pressure Test and that was sitting at 380bar. So this past Wednesday, we replaced that faulty injector and put the car on the computer again and no errors were detected, nothing! Drove the car home and she was driving perfect. Even on Thursday, she was just her perfect self. Friday, it started all over again. I must have gotten stuck 5 times before making it to the mechanic's workshop. It seems she gets hot somewhere and she just cuts and sometimes takes time to crank up after that. We did an oil change on Friday. I use strictly Castrol Edge Sport on her and Sasol's 50ppm Diesel.
But rite now, we dont know whats causing this problem. Intake Manifold we checked and its not leaking. Rail Pressure Sensor is not showing up as faulty on the computer as well. In actual fact, as far as Computer Diagnosis goes, there's nothing wrong with my car. And yet...
Some1 please help, before I go spending R8k on new Diesel Pumps, as per my mechanic's uncertain advise at this stage.
Also, could my Turbo be causing this? My car's done 283000 Ks and I have not yet changed or reconditioned the turbo.

 

[zaleonardz]

Bud...

This is a tough one,

I doubt this is turbo related, as the car should not cut out, you may surge in power and a couple of other things... but splutter and die, i doubt it.

It probably is fuel related, but consider the EKP module.

The below may be total utter crap, just thinking out loud.

See the thing with a diesel pump at such high pressure, its highly unlikely that the pump can be playing up like that, and then on a restart kinda sort itself out, and changing an injector sorta fixing the problem for a few days.

Its mechanical in nature, and mechanic either work, or not.....

I recon the problem is electrical, on restart, does she start up straight away, in other words, reseting the computer and or modules ?

 

[P1000]

Castrol Edge Sport? or normal castrol Edge? Because the sport is not the correct oil, and also not very high spec.

I doubt it is your turbo. By the way, I'm also at 283kkm on original turbo.

The diagnostics computer is not foolproof, but it usually makes it much easier to find the problem. The rail pressure is not a constant, and changes. At idle, that pressure is about right IIRC.

My guess is its a cam position sensor that fails intermittently as it gets warm. Either that or the fuel pump under the passenger seat.

 

[Sankekur]

+1 on the possibility of it being the cam position sensor.

 

[Tumie]

Bud...

This is a tough one,

I doubt this is turbo related, as the car should not cut out, you may surge in power and a couple of other things... but splutter and die, i doubt it.

It probably is fuel related, but consider the EKP module.

The below may be total utter crap, just thinking out loud.

See the thing with a diesel pump at such high pressure, its highly unlikely that the pump can be playing up like that, and then on a restart kinda sort itself out, and changing an injector sorta fixing the problem for a few days.

Its mechanical in nature, and mechanic either work, or not.....

I recon the problem is electrical, on restart, does she start up straight away, in other words, reseting the computer and or modules ?

Thanks for the response. She normally doesnt start up right away. I have to wait a few minutes, only then does she start and even when she starts, I have to b revving her, otherwise, she immediately dies again. The only time she starts up hassle free, is if I have stopped for a long time to let her cool down, say about an hour.
Also, before she cuts, what normally happens is I get the slight jerks and when I accelerate, nothing happens. Its as if the throttle suddenly dies or something. And I find myself hitting the accelerator paddle like 5 times, before she picks up power and "jumps". This is baffling...

 

[Tumie]

Castrol Edge Sport? or normal castrol Edge? Because the sport is not the correct oil, and also not very high spec.

I doubt it is your turbo. By the way, I'm also at 283kkm on original turbo.

The diagnostics computer is not foolproof, but it usually makes it much easier to find the problem. The rail pressure is not a constant, and changes. At idle, that pressure is about right IIRC.

My guess is its a cam position sensor that fails intermittently as it gets warm. Either that or the fuel pump under the passenger seat.
[/qu

Thank for the response. Been using the normal Edge and only Friday did we put the Sport Edge. My mechanic is also adamant that its the pump under the seat, although it seemed to show normal response when put on the computer. Cause Firday we did a stress test, revved it for about 10mnts and when let go of the throttle, she jerks a few and died. While all of that was happening the rail pressure test was showing 380bar and above. Will ask him to check the cam position sensor. Thanks again.

 

[netercol]

when last have you changed the diesel filter?

 

[P1000]

I think the injector issue is unrelated to the immediate problem. It could also be the MAF or a leak in the intake system, but test the crank/cam position sensors first.

 

[zaleonardz]

Listen to the buzzing of the fuel pump, does it change at all ?

I recon this is fuel pressure related...

By the way, how are you measuing the fuel rail pressure, using DIS or actually using a fuel pressure gauge on the rail ?

Bud...

This is a tough one,

I doubt this is turbo related, as the car should not cut out, you may surge in power and a couple of other things... but splutter and die, i doubt it.

It probably is fuel related, but consider the EKP module.

The below may be total utter crap, just thinking out loud.

See the thing with a diesel pump at such high pressure, its highly unlikely that the pump can be playing up like that, and then on a restart kinda sort itself out, and changing an injector sorta fixing the problem for a few days.

Its mechanical in nature, and mechanic either work, or not.....

I recon the problem is electrical, on restart, does she start up straight away, in other words, reseting the computer and or modules ?

Thanks for the response. She normally doesnt start up right away. I have to wait a few minutes, only then does she start and even when she starts, I have to b revving her, otherwise, she immediately dies again. The only time she starts up hassle free, is if I have stopped for a long time to let her cool down, say about an hour.
Also, before she cuts, what normally happens is I get the slight jerks and when I accelerate, nothing happens. Its as if the throttle suddenly dies or something. And I find myself hitting the accelerator paddle like 5 times, before she picks up power and "jumps". This is baffling...

 

[Tumie]

when last have you changed the diesel filter?

Diesel filter was changed 2 oil changes ago, which was in March this year.

---

Listen to the buzzing of the fuel pump, does it change at all ?

I recon this is fuel pressure related...

By the way, how are you measuing the fuel rail pressure, using DIS or actually using a fuel pressure gauge on the rail ?

Bud...

This is a tough one,

I doubt this is turbo related, as the car should not cut out, you may surge in power and a couple of other things... but splutter and die, i doubt it.

It probably is fuel related, but consider the EKP module.

The below may be total utter crap, just thinking out loud.

See the thing with a diesel pump at such high pressure, its highly unlikely that the pump can be playing up like that, and then on a restart kinda sort itself out, and changing an injector sorta fixing the problem for a few days.

Its mechanical in nature, and mechanic either work, or not.....

I recon the problem is electrical, on restart, does she start up straight away, in other words, reseting the computer and or modules ?

Thanks for the response. She normally doesnt start up right away. I have to wait a few minutes, only then does she start and even when she starts, I have to b revving her, otherwise, she immediately dies again. The only time she starts up hassle free, is if I have stopped for a long time to let her cool down, say about an hour.
Also, before she cuts, what normally happens is I get the slight jerks and when I accelerate, nothing happens. Its as if the throttle suddenly dies or something. And I find myself hitting the accelerator paddle like 5 times, before she picks up power and "jumps". This is baffling...

We used the DIS, it was a real time test. Will have to do the noise test on Monday, car still with the mechanic.

---

Just a quick one guys, the EKP Module fault and the Cam Position Sensor Fault, wouldn't they show up on the DIS?

 

[frikkieh]

I would replace the fuel pump at this mileage - regardless.
Is your fuel guage accurate in your opinion ?

 

[Tumie]

I would replace the fuel pump at this mileage - regardless.
Is your fuel guage accurate in your opinion ?

The fuel pumps were replaced in March this year, bought what I believe were brand new, original BMW pumps from a supposed reputable supplier in Springs. And when this problem started recently, we all thought it was the pumps, so I sent the car back to this dealer and he tested the car using DIS. He's actually the one who picked up the injector problem first and the pumps were working fine. My further research last nite really points to the Cam Position Sensor, like these other guys are saying. And none of these mechanics have mentioned it yet, so they r prob not considering it as a possible fault.