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High Pressure Fuel Pump 991 3.4

ians

New member
Joined
30 Jul 2021
Messages
45
HI All

Anybody had any experience with fuel pump problems on a 991 3.4

Car goes into limp mode with warning light on, code are

P1024 Fuel high pressure too high after engine switch off
P1027 Fuel high pressure fluctuates
P1026 Fuel high pressure implausible

Many thanks for any input

ian
 
ians said:
HI All

Anybody had any experience with fuel pump problems on a 991 3.4

Car goes into limp mode with warning light on, code are

P1024 Fuel high pressure too high after engine switch off
P1027 Fuel high pressure fluctuates
P1026 Fuel high pressure implausible

Many thanks for any input

ian

Not on a 991, but yes on a 997.2, which almost certainly has the same / similar HPFP. I got those exact same codes on mine, on my code reader and ended up needing a new fuel pump. Those are not serviceable items, replacement is the only way and so sounds very much like you need a new one!

What's the age and mileage on your car? Porsche did have a bit on an issue with these on the earlier MA1 engines, I certainly know they made a few revisions on the HPFP, you can see that via the part numbers on them.
 
Yes .. and yes you need a new high pressure fuel pump judging by those codes .


EDIT

If you have a tester capable of seeing engine actual values then look at the HPFP ..

At idle it should say actual pressure of 48 bar .. yours will probably show 5 bar or in extreme cases 200 bar !!
 
That's great many many thanks for your help

Car is a 2012 with 57K millage

deMort
I am using the Icarsoft POR 11 not sure if this can read the pump pressure

Looks like I'll be getting a new fuel pump for Christmas !

Many thanks for your help

Ian
 
I have the same codes on my 997.2 c4s, it's booked into my local Indie in January.

Annoying as it's not long since the warranty expired so I guess I will be getting a HPFP as well for Christmas.

I'm a bit disappointed in Porsche that so many cars have this problem my 987.2 cayman had the same issue .
 
Nimrod

sorry to hear, not cheap either, have you had any quotes ?

Ian
 
It is a shame that the fuel pump seems to be a bit of a weakness. If you look in the 997.2 parts catalog there are 6 revisions against this, so its clearly been improved a few time. And also as this an exchange part, I do wonder if some of the older less robust versions are being rebuilt and used.

For reference, the replacement on mine only lasted ca. 7000 miles, but thankfully failed again within the 2 year warrantee period so was replaced again foc.

On things like this, it might be where going with an OPC is better than using an Indy? I don't know maybe DeMort might answer that one.
 
I did read somewhere that there was a recall on some of the pumps on the 997

Hope at the price I get more than 7k miles on the new pump !

Regards

Ian
 
Thanks Ian .

I haven't got a quote as such just a ball park figure from the Indy after I told them the codes and that I thought it was the pump.

I originally tried to book it into the local OPC but they had no slots until Mid March which is to long for me to wait so rang the Indy I have used in the past on my 993 .

I did ask if it should have been recalled as my old 987.2 from the same age was subject to a recall but apparently it wasn't included in the campaign .
From what you have read and I maybe wrong it seems their is a pressure release valve built into the pump that seems to fail . Unfortunately this can't be replaced separately so a new pump is needed .

7000 miles is poor for a part that should last many years, the 9A1 engines maybe a lot better designed than M97 solving the IMS and bore score problems but with HPFP and possible blocked inlet valves they do seem have a annoying issues of their own from direct injection .
 
DFI systems do indeed have their own set of issues .. i've seen a pressure build up to 230 bar of pressure on a failed pump before on idle before i switched the car off ..

Bear in mind that's 3300 psi .. that's damn scary .. that sort of pressure with a pin prick hole will cut through steel !

The pump has a quantity control valve as part of it .. this is the bit that fails and also what regulates the pressure .. sensible hard driving and around 160 bar with flat out being in the 200,s .

Carbon build up on the inlet valves is a direct consequence of fuel Not being injected on to the inlet valves which will clean them but direct into the cylinders .

Going back to carburettors .. the valves carboned up as well .. but due to the .. erm .. poor design it never made a huge difference as fueling was a lot more hit and miss with these .. best we had at the time basically .

Type of oil , aos .. etc etc .. won't make a difference .. the fault if you want to call it is by design .

As i understand it most manufacturers have some sort of cleaning routine for the valves .. for most engines this can be done but on most Porsches it can be expensive .. 911 range mainly ... porsche seemed to have ignored this issue .

perhaps it's not that big of an issue then ??? i'm not sure but i have been looking into this for a while now ..

I've yet to conclusively say .. Yes the build up is causing this issue on this car ...

My job at work is primarily fault diagnosis .. and i can still say this .. i have Not proved this is an issue .

I will say a customer reported back to us after a walnut clean on a 997.2 and he said the engine feels " tighter " a bit better mpg but tighter and more crisp was how he described the difference ..

That's not a huge difference to be honest for the cost involved on these engines .

My opinion .. if you have an engine out then fair enough .. have this done .. if not .. dont worry about it .

That's my opinion as of 11/12/21 .. it may change later though !!!

EDIT ..

The recall was a long long time ago and for a different reason .. it also affected every model of Porsche with these pumps from cayenne to boxster .
 
Car been in garage today, new HP fuel pump fitted and that sorted the problem out

Thanks for all your comments and help people

Ian
 
ians said:
HI All

Anybody had any experience with fuel pump problems on a 991 3.4

Car goes into limp mode with warning light on, code are

P1024 Fuel high pressure too high after engine switch off
P1027 Fuel high pressure fluctuates
P1026 Fuel high pressure implausible

Many thanks for any input

ian

had exactly this experience in september - highly frustrating and had a pretty miserable couple of journies back to base in limp mode, at the height of the fuel shortages, drinking petrol like it ws lager. Got it replaced and all good since- seemed very strange it o
nly " went" after id done about 35-50 miles on the motorway- maybe heat/time related!?
 
ians said:
Car been in garage today, new HP fuel pump fitted and that sorted the problem out

Thanks for all your comments and help people

Ian

Well done for getting it sorted so fast!

I had to wait for ages to get mine into the OPC to replace it under warranty.

:thumbs:
 
So I have just had the HP fuel pump replaced on my 2012 C2S.
The replacement was a reconditioned pump from Porsche, I.e. one taken off another poor sod's car, 'fixed" and then sold.
Surely there should be a recall and replacement free of charge by Porsche for a part they know has an inherent weakness?!
 
And they are not cheap mine was all inc vat near £1500 would be interested to hear what they charged for a recon pump ?


Regards

Ian
 

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