Had a diagnostics done this morning to try and sort out my constant breaking down and fuelling issues. The only fault codes that came up were boost pressure fault and inlet air temps. Inlet air temp sensor when i had a look was missing its wire clip and had disconnected itself so sorted that no problem. Also when the diagnostics man was here he pulled the main engine loom about which made the engine cut out and fuel output was spiking around. He thought i may have a broken wire somewhere in the loom but i had a good look and couldnt see anything apart from the insulation split on the fuel cut solenoid wire and wire was hard so i replaced by soldering the last 9" of wire and put a new eyelet crimp on. Car runs ok now but im frightened to go anywhere in case i break down again. My question is would the boost pressure sensor (map) cause an engine management light and a failure to start. Also car was surging alot just before each breakdown
Diagnostics results on 2.5dse, thoughts please
- Thread starter leet
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rewmer
Well-Known Member
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- Clacton, Essex, UK
If your having any kind of intermittent electrical issues the first place to look is the main fuse box in the engine bay. I bet if you start wiggling the connections and relays you will be able to re-create the fault.
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- 58,170
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- Preston Lancs.
Forgive me for saying this but were you not advised to check all the sensor connections some time ago. I cannot believe you took no notice. If you had you would not have been driving around with a sensor diconnected. What is the point of people trying to help you if you take no notice of the advice given.:doh::doh::doh:
i have tried wriggling the relays and fuses but no difference. Like i said, the diagnostics man was wriggling the main engine loom and did recreate the fault. However, i have now repaired the only broken wire i could see and no matter how much i pull the loom about cannot get it to do it again. I will buy a new pressure sensor as they are peanuts in the scheme of things but do you think it could throw an engine management light and failure to start???? I really dont want to be getting on the back of an RAC truck for the 4th time this month
ill be honest and say i did not even know the inlet temp sensor existed. i actually found it unplugged wednesday and plugged it back in as well as the blue coolant sensor plug. i do listen to all advice and info as like most on here cant afford the big repair bills from a garage. i checked all the sensors which were mentioned as relevant like the crank sensor, injector4 sensor, map sensor etc but do admit i overlooked the inlet temp one. Surely though this is not enough to cut all fuel delivery?
thanks .. lee
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- 58,170
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- Preston Lancs.
Lee mate the vehicle has EDC (electronic diesel control). ALL the sensors must be working for the ECU to know properly what's going on. If one is going on and off and you have one disconnected the ECU gets a little confused and basically says, "Sod this" and shuts the engine down, and puts the take it to a dealer and get ripped off light on. The fueling depends on readings from the ECU temp sensor, the crank position sensor, the inlet air temp sensor, fuel temp sensor, number four injector. All these sensors tell the ECU to instruct the FIP to deliver a specific quantity of fuel, at a given time, for a given period, dependent on engine temp, speed, load. The MAP sensor controls fuel flow via the ECU at different turbo boost pressures in conjunction with all the other sensors. So yes, a couple of sensors down and the ECU can take a tizzy and shut the lot down. The hard wire to the cut off valve would suggest it has been getting warm, a bad connection would cause that and would also stop the fuel flow.
thankyou for that, i really do appreciate the advice. Im great on petrol engines and less complicated systems but Diesels are a wonder to me. I know absolutely nothing about them. I did phone a specialist in pangbourne (rovertune) who said it sounded like fuel quantity sensor and obviously that would require new injector pump and then started talking thousands of pounds. I just hope the new boost sensor does the trick.
i really think the previous owner has had a good go at trying to mask the problems by unplugging these various sensors and ripping me off good and proper. I think i'll also take a look at the fusebox just to rule it out over the weekend too but it does seem OK.
I dont know why but even though i have had a diagnostics session and it hasnt shown up any serious problems, i am still very apprehensive about whether its going to be ok or not as i keep breaking down without warning. Anything other than a big 4x4 auto rangerover can just be A-framed away whereas i have to rely on RAC for this.
If you haven't already, get yourself either a download or disc of RAVE. It takes a bit of searching through as it's the thick end of 2,000 pages but it does come up with nuggets like a schematic diagram of all of the sensors on the engine and then, in a different place, the locations of the sensors. At least that way you'll know that you've checked them all.
When you have a nose at the fuse box you've got to get it out of it's box and check underneath. They are prone to loose connections, which then overheat and just get worse until they fail. I have heard it said on here that the Aussies, who obviously are very nervous of break-downs in their middle of nowhere, just change the fusebox after 70 - 100k miles, depending on which site you read.
When you have a nose at the fuse box you've got to get it out of it's box and check underneath. They are prone to loose connections, which then overheat and just get worse until they fail. I have heard it said on here that the Aussies, who obviously are very nervous of break-downs in their middle of nowhere, just change the fusebox after 70 - 100k miles, depending on which site you read.
