Technical Multijet sudden loss of power

[Grumple]

Hi all,

After going through several posts on here about this issue, I am still struggling to fix it.

Car is a 57 plate 1.3 multijet.

It had been sat for around a month and drove 10 miles or so absolutely fine. On the return journey it just lost the ability to accelerate at all... No other signs that anything was wrong, just flooring it and going virtually nowhere.

I've taken the airbox off and there is no moisture anywhere (not in MAF or ECU either).

I've also freed up the waste gate actuator (which wasn't moving much).

So what can I try next?


It sounds totally normal on idle, and will move fine in reverse and upto about 10mph, then it just keeps revving up (very slowly) and not going anywhere. I thought the moisture in the airbox sounded exactly what it could be, because it sounds like it's struggling for air (almost misfiring).

Any guidance would be massively appreciated because I can't afford a mechanic to problem solve for hours.

Cheers!

 

[g8rpi]

Hi all,

After going through several posts on here about this issue, I am still struggling to fix it.

Car is a 57 plate 1.3 multijet.

It had been sat for around a month and drove 10 miles or so absolutely fine. On the return journey it just lost the ability to accelerate at all... No other signs that anything was wrong, just flooring it and going virtually nowhere.

I've taken the airbox off and there is no moisture anywhere (not in MAF or ECU either).

I've also freed up the waste gate actuator (which wasn't moving much).

So what can I try next?


It sounds totally normal on idle, and will move fine in reverse and upto about 10mph, then it just keeps revving up (very slowly) and not going anywhere. I thought the moisture in the airbox sounded exactly what it could be, because it sounds like it's struggling for air (almost misfiring).

Any guidance would be massively appreciated because I can't afford a mechanic to problem solve for hours.

Cheers!

Hi welcome to Fiat Forum,

Sounds like it could be a fuel problem. Possibly a blocked filter or failed pump either in tank or high presure. Ideally you need to get diagnostic software on the car, for example Multiecuscan. See www.multiecuscan.net the registration fee is 50 Euros you also need an interface and leads which cost around £30 e.g. www.ebay.co.uk/itm/NEW-Fiat-Alfa-EL...dapters-Diagnostics-Multiecuscan/282526378637 and a PC laptop (anything running Windows XP or newer). This is cheaper than a dealer will charge for a single diagnstics read even if you had to buy a used laptop. Simple code readers and non-Fiat specific apps won't give the same level of information as Multiecuscan.

If you don't want to spend that much, at least change the fuel filter.


Robert G8RPI.

 

[Grumple]

Thanks for the quick response Robert.

What makes you think it's a fuel problem? Just for my own understanding.

I'll order a filter and see if it improves!

 

[Kronkron]

Sound similar to problems I had with a diesel Ford, turned out it was the fuel filter. For the cost and simplicity of changing it out for a fresh one I would try that first.

 

[Wee Smurf]

The moisture in the airbox results in a loss of power after around one hundred yards and it will clear itself and then run fine after a few hundred yards more.
As above I'd reckon fuel pump or filter.

 

[g8rpi]

Thanks for the quick response Robert.

What makes you think it's a fuel problem? Just for my own understanding.

I'll order a filter and see if it improves!

Loss of throttle response in a diesel without rough running or lots of smoke is typically a lack of fuel. For a car that has sat a while contaminants in an old filter can solidify and block it reducing flow. Enough flowfor idle and low power but not much more.


Robert G8RPI.

 

[Pugglt Auld Jock]

I agree with the consensus above. Highly likely to be a fuel problem and a new filter is such a cheap fix it's worth just trying one.

If you are at all practical, or know someone knowledgeable who is prepared to help you then go and give Multiecuscan a try. I've now owned my registered copy for just under a year and it's a powerful and fairly easy to use tool.

Good luck. Do let us know the outcome?

 

[DaveMcT]

Filters generally clog up gradually, so a sudden loss of power could be the in-tank fuel pump. You should hear it working when you turn on the ignition.


Otherwise, you'll need to get a scanner on the ECU codes.

 

[Grumple]

Loss of throttle response in a diesel without rough running or lots of smoke is typically a lack of fuel. For a car that has sat a while contaminants in an old filter can solidify and block it reducing flow. Enough flowfor idle and low power but not much more.


Robert G8RPI.

OK, thanks for the clear info and advice!

I've ordered a new filter (with the tool to make life easier - can sell on afterwards), so will give it a go at the weekend and let you know how it goes.

 

[Grumple]

No luck.

New filter in and still exactly the same.

It's struggling to turn over/start so I'm thinking it's most likely the fuel pump now.

What to try next?

 

[Wee Smurf]

Tank fuel pump cheaper than high pressure one. My high pressure fuel pump went and my car wee'd diesel on the road. No leaks visible?

 

[Grumple]

Not that I noticed. Do I check this with the engine running?

I've had a quick look on ebay and there are some tank pumps for £70+ and others around £40. Which should I be going for?

Cheers!

 

[chris3234]

Do you have multiecuscan?
As you can monitor the fuel rail pressure via that
A lot cheaper then getting a pump when you don't know it's faulty

 

[Grumple]

No I don't have that software - €50 + cost of leads and time to learn it doesn't work out cheaper or easier for me personally.

From the sounds of it, it's one of the fuel pumps, so I might as well attempt to replace the cheaper one (especially if its only £40).

If its the high pressure one, then I'm not sure it's even worth fixing - I'd just sell it on and replace it.

 

[DaveMcT]

Multi ECU Scan is free. The £50 paid-for version adds a few features (airbags, etc) but they are unlikely to affect your needs.

That has to be cheaper than taking a guess and changing stuff on a hunch.

 

[goggs]

Dare I say symtoms like a MAF needing cleaned. Mines getting worked on at mo due to black death on one and rough running when cold. It's amazing what you learn about removing injectors easily.

 

[Grumple]

Well, that didn't work!

Tank fuel pump replaced (getting the rear bench out is the hardest part of this for anyone attempting).

I'll try and get the ECU checked out to see if that can highlight anything.

But is the only likely remaining option the high pressure fuel pump?

Thanks for any advice.

 

[Grumple]

Dare I say symtoms like a MAF needing cleaned. Mines getting worked on at mo due to black death on one and rough running when cold. It's amazing what you learn about removing injectors easily.

Everything in the airbox and MAF was squeaky clean and dry.

 

[Grumple]

Multi ECU Scan is free. The £50 paid-for version adds a few features (airbags, etc) but they are unlikely to affect your needs.

That has to be cheaper than taking a guess and changing stuff on a hunch.

Sorry Dave, didn't see the free version.

My concern with this is I wouldn't have a clue what it was telling me or how to find out what I need from it.

 

[g8rpi]

Multi ECU Scan is free. The £50 paid-for version adds a few features (airbags, etc) but they are unlikely to affect your needs.

That has to be cheaper than taking a guess and changing stuff on a hunch.

Depends on the model of car and exact ECU fitted. The Marelli 8DF CF5ECU fitted to some Panda 1.3 MJD needs the registered version.
I do agree that €50 for MES and <£30 for a good ELM327 interface (and leads) is sill cheaper than changing parts on a guess or even gettinf a diagnostic read from a dealer.


Robert G8RPI.