Check Engine Light on with code 1026
10-08-2014, 11:51 PM
#1
Rennlist Member
Thread Starter
Check Engine Light on with code 1026 / HPFP replacement
I was driving my GTS, when the CEL came on as I was slowing down for a stop light. Nothing occurred that caught my attention, but as I began to accelerate I noticed that it would not rev over 3k RPM. Otherwise, it was running fine.
When I got home, I hooked up the Durametric, and pulled the engine codes. The only fault code was 1026 - Fuel Pressure Implausible. Value below lower limit value.
I cleared the code, and attempted to start the car up, it cranked a good 4 seconds before I stopped. Tried again, and started up after another 3 or 4 seconds of cranking. It was running horribly, sounding like it was missing on 2 or 3 cylinders.
It sounds like I'm the next victim of the HPFP failures. Time to order one up and see what happens.
When I got home, I hooked up the Durametric, and pulled the engine codes. The only fault code was 1026 - Fuel Pressure Implausible. Value below lower limit value.
I cleared the code, and attempted to start the car up, it cranked a good 4 seconds before I stopped. Tried again, and started up after another 3 or 4 seconds of cranking. It was running horribly, sounding like it was missing on 2 or 3 cylinders.
It sounds like I'm the next victim of the HPFP failures. Time to order one up and see what happens.
Last edited by Chris51080; 10-17-2014 at 10:47 PM.
10-17-2014, 11:01 PM
#2
Rennlist Member
Thread Starter
For future reference:
I ordered a replacement High Pressure Fuel Pump from ECS, and with my work schedule finally got around to installing it tonight. Everything works perfectly now.
Its incredibly simple to replace the high pressure rule pump, there are 4 bolts, 2 spacers and an electrical connection. Total time though was 90 minutes though, because the bolts are on the back side of the engine and there is almost zero room. If you attempt this, you better not have large hands and you will end up with bloody knuckles.
Tools:
10mm wrench
14mm wrench
17mm wrench
Torx bit (T-25 i think to remove the trim in the engine compartment)
Start by removing the plastic covers on the Left and Center of the engine bay. This will require the torx bit and a large flathead screwdriver or a quarter.
The high pressure fuel pump is located on the back side of the left head. You will need to get your hands between the firewall and the engine in order to remove it. Try it, and if you don't fit at all...find a small child to do your work.
There are 3 10mm bolts that hold a heavy steel plate, that appears to protect the fuel pump in the event of a collision. The top two bolts aren't too bad, but the bottom one is done by feel alone. I highly recommend that you use a gear wrench or similar when trying to work back here.
Once the plate has been removed, you will want to loosen the fuel lines. The upper line is 14mm while the lower line is 17mm. Fuel will come out, so be aware. The upper line is the high pressure line, and is hard piped from the fuel pump. Disconnect it and use a rag to capture as much of the fuel as you can.
The lower line is a rubber hose with a metal fitting. When you unscrew this one, fuel will again come out so be prepared with a rag. You will be able to maneuver this line out of your way; I let a bit of the fuel drain out then placed this line on the intake manifold/plastic cover.
Next you can remove the 2 spacers and one bolt that hold the fuel pump in place. These are all 10mm connections. Again, the upper two are pretty easy. The bottom spacer is done blind, but with the metal plate out of the way it isn't too bad.
After the spacers and bolts are removed, you can rotate the fuel pump side to side as you gently pull it toward the firewall. It will come out. Once it is free, you can maneuver it above the head and remove the electrical connection on the bottom.
From here, installation is the reverse of removal. The metal plate is by far the most difficult. Just be sure to start all of your bolts and spacers by hand, and good luck not dropping anything.
Once complete, sit back and enjoy a cold beer.
I ordered a replacement High Pressure Fuel Pump from ECS, and with my work schedule finally got around to installing it tonight. Everything works perfectly now.
Its incredibly simple to replace the high pressure rule pump, there are 4 bolts, 2 spacers and an electrical connection. Total time though was 90 minutes though, because the bolts are on the back side of the engine and there is almost zero room. If you attempt this, you better not have large hands and you will end up with bloody knuckles.
Tools:
10mm wrench
14mm wrench
17mm wrench
Torx bit (T-25 i think to remove the trim in the engine compartment)
Start by removing the plastic covers on the Left and Center of the engine bay. This will require the torx bit and a large flathead screwdriver or a quarter.
The high pressure fuel pump is located on the back side of the left head. You will need to get your hands between the firewall and the engine in order to remove it. Try it, and if you don't fit at all...find a small child to do your work.
There are 3 10mm bolts that hold a heavy steel plate, that appears to protect the fuel pump in the event of a collision. The top two bolts aren't too bad, but the bottom one is done by feel alone. I highly recommend that you use a gear wrench or similar when trying to work back here.
Once the plate has been removed, you will want to loosen the fuel lines. The upper line is 14mm while the lower line is 17mm. Fuel will come out, so be aware. The upper line is the high pressure line, and is hard piped from the fuel pump. Disconnect it and use a rag to capture as much of the fuel as you can.
The lower line is a rubber hose with a metal fitting. When you unscrew this one, fuel will again come out so be prepared with a rag. You will be able to maneuver this line out of your way; I let a bit of the fuel drain out then placed this line on the intake manifold/plastic cover.
Next you can remove the 2 spacers and one bolt that hold the fuel pump in place. These are all 10mm connections. Again, the upper two are pretty easy. The bottom spacer is done blind, but with the metal plate out of the way it isn't too bad.
After the spacers and bolts are removed, you can rotate the fuel pump side to side as you gently pull it toward the firewall. It will come out. Once it is free, you can maneuver it above the head and remove the electrical connection on the bottom.
From here, installation is the reverse of removal. The metal plate is by far the most difficult. Just be sure to start all of your bolts and spacers by hand, and good luck not dropping anything.
Once complete, sit back and enjoy a cold beer.
02-24-2018, 11:59 PM
#4
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You might take a look at: https://rennlist.com/forums/cayenne-...placement.html - while they are different era Cayennes - the HPFP is basically the same, and R&R are basically the same. I do believe there is a resin sort of coupling used to the camshaft end on the 957 cars - that has been replaced with metal on the 958 vehicles. I've heard stories about the coupling disintegrating when removal is attempted. Just a heads up on that.
03-01-2018, 12:45 PM
#5
UPDATE: Installed the new HPFP. The p1026 went away right after the install with no need to clear.....cool.
Pretty straight forward following Chris' direction after reviewing PelicanParts photos. On the 957 GTS, absolutely no need to remove the intake manifold.
I found it easier to remove the hard fuel line on the top only, then when pulled out to remove the lower line. Also I found it so much easier to insert the adapter into the engine then align the HPFP with it and mount it. The hardest part is not to drop anything or be ready to remove the floor panels below. If you can climb on the top of the engine bay and work from the top it is much better then of the side.
Favorite part is to finally get an instant start this morning. No more long cranks. I drove the car yesterday for 100 miles. Noticeably smoother drive, it also seemed my fuel economy slightly improved.
IMPORTANT POINTER: Make sure to connect the fuel line very tight to avoid the fuel leak. Especially the upper hard line. After the instal, check for leaks!!
Pretty straight forward following Chris' direction after reviewing PelicanParts photos. On the 957 GTS, absolutely no need to remove the intake manifold.
I found it easier to remove the hard fuel line on the top only, then when pulled out to remove the lower line. Also I found it so much easier to insert the adapter into the engine then align the HPFP with it and mount it. The hardest part is not to drop anything or be ready to remove the floor panels below. If you can climb on the top of the engine bay and work from the top it is much better then of the side.
Favorite part is to finally get an instant start this morning. No more long cranks. I drove the car yesterday for 100 miles. Noticeably smoother drive, it also seemed my fuel economy slightly improved.
IMPORTANT POINTER: Make sure to connect the fuel line very tight to avoid the fuel leak. Especially the upper hard line. After the instal, check for leaks!!
03-01-2018, 01:01 PM
#6
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I noticed a few people mentioning getting on top of the engine.. I'd be somewhat afraid of breaking some of the crappola plastic hoses/pipes that Porsche loves to use. Any clues how you do get on top of the engine to work back there?
03-01-2018, 02:48 PM
#7
I was able lay down thick towel between the front bumper and the engine bay and work on my knees from the top with no issues with me being 170 pounds.
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09-27-2018, 08:01 PM
#8
Rennlist Member
957 fuel pressure issues due elevation??
I own a 2010 cayenne s with 77K that has experienced what I believe to be a fuel delivery issue. Fault codes P1026 HPFP and 12A1 fuel rail pressure sensor were indicated on my reader. I have researched numerous forum threads that may relate to my issue and am finding no direct connection. I live in the Colorado mtns.(9200FT) Over the past two years when returning home after visiting Denve(5280FT), 4 out of 15 times I have experienced violent bucking, hesitation, stalling, then sudden acceleration when pumping gas pedal only to be repeated over and over if/when I reach the top of Berthoud Pass (11,000 FT). The SUV smooths out once I reach the top and begin descent. The check engine light appears. When I fill the SUV with gas near my home afterward the check engine light disappears and engine resumes normal operation. I have had the 12A1 code appear after the previous 3 occasions. The common thread has been that I fill up with gas in Denver right before travelling home. If I fill up near my home and drive to Denver and return on the same tank of gas the nasty symptoms do not occur. These symptoms have only occurred driving up the east side of the Pass starting at Empire (8600ft) and never on the west side of the Pass my way to Denver. Any thoughts on how to accurately diagnose/repair an intermittent problem that disappears after climbing the Pass?
