Diesel, poor performance, £3700 to fix!

Roverron · 10th October 2007, 14:26

This is a cautionary tale of a ZT bought with poor performance.
The performance was bad at low rpm as if the maf sensor was out of spec. The chap bought a Synergy in the hope this would improve the performance. But it then also cut out at 3000rpm and eventually would not start, or it would start and rev off-load, but cut out on load.

He had changed the following in the order below:

Maf sensor - 3 times - still same.
Injectors serviced - little better
low pressure pumps
fuel rail sensor
HP pressure regulator
ecu
HP pump

The FCR reported low, high-side pressure as if fuel starvation was occurring and this explained the cutting out at 3000rpm under load and bad starting.

When the ecu did not fix it, we were all convinced the HP pump was the culprit - what else could there be?

It was the allegedly serviced injectors. The garage that did them either didn't change them or the ones they fitted were some 'old ones they had lying about'. They will be receiving an invitation to offer substantial compensation.

The rail sensor, HP regulator, ecu and HP pump rarely give problems (apart from water getting to the ecu from blocked plenum drains) but in believing that service exchange injectors had indeed been fitted, it was inevitable that an expensive path was going to be followed.

So anyone with intractable performance problems, contact the MG Owners Club in Cambridge. They also have the tool needed to change the HP pump in situ.

Ron

grossebaby · 10th October 2007, 19:38

Hi Ron

Just worrying me about my leaking HP pump, it is from the top and side plates and my mechanic wants to remove and send away for refurb.

Is it an engine out job???????

The leak is only when card is really cold and cold start is running!!!!

Any luck on my mafam, maf and bmc cleaner yet?

Piers

MGOracle · 10th October 2007, 19:48

Ron, re my other post tonight,

I'm going to say I dis-agree about the regulator. I think it is a strong culprit (and this is by no means derogitory towards you) but I think extended use and mileage of the synergy unit pushes the regulator seal beyond it's limits.

I'm on my second in 10 months at a cost of £250 to replace each time.

Unfortunately, driving the 'old' ZT (non synergy) is just too boring for me!

MGOracle · 10th October 2007, 19:50

Quote:

Originally Posted by grossebaby

Hi Ron

Just worrying me about my leaking HP pump, it is from the top and side plates and my mechanic wants to remove and send away for refurb.

Is it an engine out job???????

The leak is only when card is really cold and cold start is running!!!!

Any luck on my mafam, maf and bmc cleaner yet?

Piers

Hi mate, no, the entire HP pump will have to be removed to access those plates as one of the tork bolts is inaccessable otherwise.

I have a HP pump here for sale if you are interested.

You need a special tool to remove the pump (available at BMW as well but the tool is mega expensive). Otherwise its an engine out job.

Roverron · 10th October 2007, 20:32

Quote:

Originally Posted by grossebaby

Hi Ron

Just worrying me about my leaking HP pump, it is from the top and side plates and my mechanic wants to remove and send away for refurb.

Is it an engine out job???????

The leak is only when card is really cold and cold start is running!!!!

Any luck on my mafam, maf and bmc cleaner yet?

Piers

You don't need to take the engine out provided you have the special tool. Then its quite straightforward.

Mafam etc will be in the post by monday. Sorry for the delay.
Cheers, Ron

grossebaby · 11th October 2007, 07:01

Hi Ron

Cheers, but don't let Postman Pats unpaid holiday plans trouble the delivery.

If they strike by all means wait, just let me know.

Piers

jopena · 11th October 2007, 11:26

Quote:

Originally Posted by Roverron

This is a cautionary tale of a ZT bought with poor performance.
The performance was bad at low rpm as if the maf sensor was out of spec. The chap bought a Synergy in the hope this would improve the performance. But it then also cut out at 3000rpm and eventually would not start, or it would start and rev off-load, but cut out on load.

He had changed the following in the order below:

Maf sensor - 3 times - still same.
Injectors serviced - little better
low pressure pumps
fuel rail sensor
HP pressure regulator
ecu
HP pump

The FCR reported low, high-side pressure as if fuel starvation was occurring and this explained the cutting out at 3000rpm under load and bad starting.

When the ecu did not fix it, we were all convinced the HP pump was the culprit - what else could there be?

It was the allegedly serviced injectors. The garage that did them either didn't change them or the ones they fitted were some 'old ones they had lying about'. They will be receiving an invitation to offer substantial compensation.

The rail sensor, HP regulator, ecu and HP pump rarely give problems (apart from water getting to the ecu from blocked plenum drains) but in believing that service exchange injectors had indeed been fitted, it was inevitable that an expensive path was going to be followed.

So anyone with intractable performance problems, contact the MG Owners Club in Cambridge. They also have the tool needed to change the HP pump in situ.

Ron

Hi Ron I have exactly the same problem. And I haven't found the problem yet.
The last thing that was diagnosed is faulty injectors.
The Bosch service i went in told me that i have to change 2nd and 3rd injector. (I have changed 1st and 4th in the last 4-5 months). They try to service them but didn't manage to get them in the standard.
Some Bosch garages have machines that can check the injectors individually . My 3rd injector is working now with +10mm correction , so i hope by replacing them (2nd is also out of order) to solve the problem. I will write if the problem is gone.

MGOracle · 11th October 2007, 12:41

Sounds to me like a lot of people are getting ripped off here for a simple solution.

I was told two of my injectors were bad. I checked them myself following Rons tips and they weren't.

Not surprising really, the garage wanted £125 each to refurb them not including labour to take them out, etc. or £250 each for new.

In the end I took it somewhere very reputable and it was a dodgy seal in the regulator.

unimatrix1066 · 11th October 2007, 16:12

ive just had one of my injectors serviced and it cost me 80.00 cash, and was done the same day, after following rons tips on injector leak back which i removed and fitted myself(haynes manual is a bit misleading on procedure you do not need to remove the torx studs)

Roverron · 11th October 2007, 18:03

Quote:

Originally Posted by MGOracle

Ron, re my other post tonight,

I'm going to say I dis-agree about the regulator. I think it is a strong culprit (and this is by no means derogitory towards you) but I think extended use and mileage of the synergy unit pushes the regulator seal beyond it's limits.

I'm on my second in 10 months at a cost of £250 to replace each time.

Unfortunately, driving the 'old' ZT (non synergy) is just too boring for me!

You must be unlucky!
I don't know of anyone but you that has had HP regulator problems. I can't see why the seals would go just because the regulator is 'wider open' more of the time on an engine with a common rail tuning box.
The ecu varies the regulator valve position by pulsing the solenoid on and off so how this can wear the seal more rapidly is beyond me. Only on full throttle would the valve stroke be at minimum and the duty cycle be at maximum.

Ron

10th October 2007, 14:26	#1
Roverron Gets stuck in Rover Join Date: Nov 2006 Location: Tarbert Posts: 980 Thanks: 0 Thanked 19 Times in 9 Posts	Diesel, poor performance, £3700 to fix! This is a cautionary tale of a ZT bought with poor performance. The performance was bad at low rpm as if the maf sensor was out of spec. The chap bought a Synergy in the hope this would improve the performance. But it then also cut out at 3000rpm and eventually would not start, or it would start and rev off-load, but cut out on load. He had changed the following in the order below: Maf sensor - 3 times - still same. Injectors serviced - little better low pressure pumps fuel rail sensor HP pressure regulator ecu HP pump The FCR reported low, high-side pressure as if fuel starvation was occurring and this explained the cutting out at 3000rpm under load and bad starting. When the ecu did not fix it, we were all convinced the HP pump was the culprit - what else could there be? It was the allegedly serviced injectors. The garage that did them either didn't change them or the ones they fitted were some 'old ones they had lying about'. They will be receiving an invitation to offer substantial compensation. The rail sensor, HP regulator, ecu and HP pump rarely give problems (apart from water getting to the ecu from blocked plenum drains) but in believing that service exchange injectors had indeed been fitted, it was inevitable that an expensive path was going to be followed. So anyone with intractable performance problems, contact the MG Owners Club in Cambridge. They also have the tool needed to change the HP pump in situ. Ron __________________ [SIGPIC][/SIGPIC] Click to visit my website Ron on Twitter MyFacebook page

10th October 2007, 19:38	#2
grossebaby Gets stuck in SUBARU LEGACY DIESEL Join Date: Sep 2007 Location: Halifax Posts: 508 Thanks: 0 Thanked 0 Times in 0 Posts	Hp Pump in situ???? Hi Ron Just worrying me about my leaking HP pump, it is from the top and side plates and my mechanic wants to remove and send away for refurb. Is it an engine out job??????? The leak is only when card is really cold and cold start is running!!!! Any luck on my mafam, maf and bmc cleaner yet? Piers

11th October 2007, 07:01	#6
grossebaby Gets stuck in SUBARU LEGACY DIESEL Join Date: Sep 2007 Location: Halifax Posts: 508 Thanks: 0 Thanked 0 Times in 0 Posts	Postman Pat Hi Ron Cheers, but don't let Postman Pats unpaid holiday plans trouble the delivery. If they strike by all means wait, just let me know. Piers

10th October 2007, 19:48	#3
MGOracle Banned MG ZT CDTi 135+ Join Date: Mar 2007 Location: Cardiff Posts: 1 Thanks: 0 Thanked 5 Times in 2 Posts	Ron, re my other post tonight, I'm going to say I dis-agree about the regulator. I think it is a strong culprit (and this is by no means derogitory towards you) but I think extended use and mileage of the synergy unit pushes the regulator seal beyond it's limits. I'm on my second in 10 months at a cost of £250 to replace each time. Unfortunately, driving the 'old' ZT (non synergy) is just too boring for me!

11th October 2007, 12:41	#8
MGOracle Banned MG ZT CDTi 135+ Join Date: Mar 2007 Location: Cardiff Posts: 1 Thanks: 0 Thanked 5 Times in 2 Posts	Sounds to me like a lot of people are getting ripped off here for a simple solution. I was told two of my injectors were bad. I checked them myself following Rons tips and they weren't. Not surprising really, the garage wanted £125 each to refurb them not including labour to take them out, etc. or £250 each for new. In the end I took it somewhere very reputable and it was a dodgy seal in the regulator.

11th October 2007, 16:12	#9
unimatrix1066 Avid contributor Zt and zr express van morris minor Join Date: Apr 2007 Location: partridge green Posts: 188 Thanks: 3 Thanked 5 Times in 4 Posts	ive just had one of my injectors serviced and it cost me 80.00 cash, and was done the same day, after following rons tips on injector leak back which i removed and fitted myself(haynes manual is a bit misleading on procedure you do not need to remove the torx studs)