I spoke to Dave Croft yesterday and after coming home and re thinking what I have done it does break down into a fairly simple segments, as per burrows dean comments. I have a spare HPP, so I may just overhaul that one and then is done, I will need to get hold of a tester for the tank pump. I have checked the sensors as per Autodata info and they are reporting OK. here hoping for a result.

SHE LIVES, and again its difficult to really know what the problem was/is. However, I decided that the issue was electrical and not sensor or fuel related, so I started to check all the fuses and wiring very carefully, to be honest I did not really find any problems as such just fuses and connections not s clean as they might be. Anyway I hit the button and bingo.
Thanks for your help and comments, I will hang on to it for a few days and fiddle with they wires to see if I can reproduce the problem. Keep the faith(sign of my age)

Great news.
Shame you didnt find a true fault though. Charlie

varesecrazy said:

Great news.
Shame you didnt find a true fault though. Charlie

Click to expand...

Philjay51

While still fresh in your mind. Can you please give a summary of..
What you changed in hope..
And a list of the last day of work-when it finally started..and ran

Cheers. Charlie

varesecrazy said:

Philjay51

While still fresh in your mind. Can you please give a summary of..
What you changed in hope..
And a list of the last day of work-when it finally started..and ran

Cheers. Charlie

Click to expand...

In answer to your question I try to follow a patten, not always easy as I have the attention span of a nat.
I have a spare fuel sensor and regulator as well as a HPP. I changed the sender and regulator, no effect. Checked wiring continuity to the ECU, also checked the outputs resistance of the Sensors etc, could not get a voltage reading of them with the engine running, obviously. My spare HPP was not working correctly so having put it on I took it straight off, checked that the lift pump was doing something, but could not check actual pressure BUT, MES was telling me that there was reasonable pressure in the fuel rail so I was reasonably happy that it was working correctly. I then went through all the fuses and connections, including those to the sensors (again) and at that point the P0090 error went out on reset. Turned key and BINGO.
My daughter has the car back at the moment but next week I am going to see if I can simulate the problem, I think that the sensors must run through a fuse and thats were the issue is, or a bad connection. I will let you know what happens.
One other comment, once started it was very smokey, it soon cleared but I felt the car was not performing as well as it had in the past and it had a bit of a flat spot, may just need a good blow out as it only does short journeys.
One other thing has just occurred to me, I tried actuation the fuel regulator though MES and I could not hear it or indeed feel it as suggested by them, I did not go back and check if I could hear it once the car was running, thats something else for me to revisit.

Well, it's happened again, same issues leading up to the problem and them it died. P0090, it will clear but not starting. This car has got to go, I am very disappointed, never had these kind of problems with a Fiat( believe it or not) let alone any other car except a Range Rover, that was the HPP. Anyway its raining, so it will have to wait. Anybody want a project?

Philjay51 said:

Well, it's happened again, same issues leading up to the problem and them it died. P0090, it will clear but not starting. This car has got to go, I am very disappointed, never had these kind of problems with a Fiat( believe it or not) let alone any other car except a Range Rover, that was the HPP. Anyway its raining, so it will have to wait. Anybody want a project?

Click to expand...

Crikey..!!

What are the rail pressures showing?
Mainly out of interest..

Err, I think it was reporting 10 bar with a require number of 400. But I have seem these number before so nothing surprises me. One thing though, when, if the rain stops I am going to remove the fuse box and carefully check that over. I have the ignition on and I was checking the fuses, I pulled a fuse, it was OK put it back and the fuel pump started, strange, I pulled the fuel pump fuse, it was OK, put it back and the fuel pump started. Very strange, I am thinking, hoping there is an internal issue with the fuse box. I firmly believe that the problem is wiring not the sensors giving problems. Hey ho.

Well, I think I have cracked it..... I took the fuse box apart, not much to see and nothing obvious wrong with it BUT while it was out I switch the ignition on and played with the fuel pump fuse and guess what, it worked intermittently. So I fiddled with the connections and bingo, car starts. Yea!!!!!

Still want to sell it..

To be honest I think I will, I offered my daughter my wife's Grande Punto, (she declined at the time, but I think she may well reconsider) only so I could get an Arbarth version and I think I may go down that route.

I lied, ran on the drive and as soon as I tried to move away it died and wil not restart. Seriously fed up now.

That was a mammoth read and a rollercoaster ride.

It’s been a really wet couple of days this way so maybe your way too… problems not related to the daughter driving through big puddles?

Seems to me either the fuel rail pressure is going low (hp pump fault or too much leakoff at any point on the HP side) or an electrical problem.

I’d also swing towards checking the easier thing first - as the old rail engineer told you – oh sorry railway engineer – not fuel rail engineer :doh:

If you’ve already done it I must have missed it in this thread.

Electrical signal path from rail pressure sensor to ECU - did you check the wires between the fuel pressure sensor and the ECU for good electrical continuity?

Looking at the fuel rail in the eper the sensor (3) in is at the other end on the fuel rail to the pressure regulator (2). There is only 1 perimeter a sensor on the fuel rail is monitoring…. Fuel pressure



I think the fuel regulator at the battery end also has an electrical connection (looking at pics I took from when I replaced by MJ fuel pump). Probably worth checking both electrical paths to the ECU. Have a low resistance. I’ve no idea which pin but the wire colour code may be constant if there are no fuses in the way. May be worth checking the rail it’s self has a good ground path back to the battery (if it’s grounded).

Ahhh I found a good pic of my rail and you can see the electrical connectors at each end... A = Rail Pressure sensor, B = electrical connector to rail pressure regulator, C = Fuel rail leakoff hose



Not sure what peramiter is being picked up from the connection to the regulator but I suspect it's not rail pressure.


If the signal path is good then check the pressure sensor is good (no idea how to check it) and then the pressure in the rail (no idea how to check that) but there is plenty on the Corsa side of things if googling P0090. It’s a generic code after all


Did you spray that Italian contact cleaner on the both fuel rail and ECU plugs? Think I had damp in there once.

Regarding the in filter fuel heater yes there is supposed to be one in the Panda’s UFI filter housing. I’ve been told where I work that it’s redundant in the UK as we have winter fuel… Our similar engines run fine without heating the fuel on arctic cold days. this is off highway tackle mind you

Hmmm maybe it is an electrical connection issue as there is no rail pressure before the engine is turned over.

I think if a sensor could operate between 1 and 100, 0 through 10 and 90 through 100 may be fault zones and a good signal zone would be between 11 and 89

No units in my theory but this vid at around 20 seconds in states the 5V 3 wire sensor has an output range of 0.5V to 4.5 V




So a 0V - 0.49V and 4.6V - 5.0V are in fault range to allow open and short circuit detection up cct (i guess) or perameter out of expected value.

Could be electrical or the sensor it's self.

Ah watching a bit more this vid tells you how to check the sensor if it's a 3 wire 5V jobbie

Last reply tonight...

This sounds much more regular and palatable ...

A real MJ and the readings for off and on engine (when you get that far)





Ahh and the electrical connector to the other end is....



The electronic rail pressure control valve

Edit....

here are the RAC's MJ vids https://www.youtube.com/user/RACBreakdown/search?query=multijet

gonna get my popcorn now

Lauie Bee, thanks for your late night research, TBH I have gone down that road but I decided that it would not hurt to revisit the whole proceedure again and of course recheck the voltages etc. First thing this morning I put it back together (connect battery) and low and behold it started, ran for a couple of minutes and then failed. I then checked all the continuity and voltages, all OK. I also cleaned the boost sensor and MAF while I was at it. I managed to let the battery go flat so I changed the battery and cranked it over, now here's the strange thing, I did not think it was going to start as it was cranking over a lot but it sounded slightly different so I persisted and it fired. I left it running, at one point it started to hunt and seemed to develope a misfire. Anyway, it kept going so I ran it at about 2.5k rpm stopped it, restarted, again it needed a bit of cranking. So I am letting have a little think about itself before I try again. As I cannot find an absolute reason for the fault, I will advise my daughter to get rid of it. I will be sorry to see it go but they need a reliable car.
Thanks to everybody for there help and advise......again, and hopefully for the last time.
OHHH, one thing I forgot to mention, I changed the fuel rail sensor and solenoid for a couple of spares I had kicking around, the sensor is the original one off the car.

Well it has bitten me in the arse, I took it out for a run this morning, it felt fine, pulled well. I got the engine warm and as I pulled out of a junction I pushed it a little harder, I noticed some smoke out of the back and then the Engine light came on and the engine stopped. Needless to say it would not start. If anybody wants a project its sitting on the side of the road were I left it!

My self-employed son has a Renault work van. For two months it showed a variety of fault codes and stopped at random.
After suspecting and testing/swapping just about every sensor, fuse and relay on the vehicle, in desperation we began testing every wire in the loom, using two needles with a multimeter, checking resistance of every wire.

We finally found a wire that had partly broken under its plastic sheath, that only showed up when jiggled, giving a variable resistance as the harness moved. Fixed the wire and all has been well since.

You never know .....

Sweetsixteen said:

My self-employed son has a Renault work van. For two months it showed a variety of fault codes and stopped at random.
After suspecting and testing/swapping just about every sensor, fuse and relay on the vehicle, in desperation we began testing every wire in the loom, using two needles with a multimeter, checking resistance of every wire.

We finally found a wire that had partly broken under its plastic sheath, that only showed up when jiggled, giving a variable resistance as the harness moved. Fixed the wire and all has been well since.

You never know .....

Click to expand...

No, I absolutely agree with you, I have done this with what I thought would be the offending cables without success, having said that, it's the only thing I can think of to do.

Question, is there a trick to opening the plugs that connect thr loom to the ECU, I don't want to break them open.