Menu
What's new
By:
Advanced search...

2.2 Diesel - P1065 when flooring in high gear

Trawa

Trawa

Active Member
Messages
194
Reaction score
54
Location
Sheffield
Car
CU2 Modulo 6MT
Hey, got a 7th gen 2.2 for the missus and it throws the CEL and flashing coil light after about 2 seconds if you floor it in high gear (4-5-6) below 2000ish RPM. Lower gears no issues, RPM above that no issues, pulls like it should. When punching it from low RPM you can hear the turbo start spooling and then it cuts into limp mode, it's not instant. Accelerating gently from lower revs doesn't trigger the CEL. I've seen that code pointing towards a clogged fuel filter but figured it's worth asking first before firing the parts cannon at it as I have zero experience with diesels.
Car has been sat for a long time prior. No issues starting hot or cold.
It's a 08 plate facelift so I'm ***uming 16901-RJL-E01 (spin on type) is the correct filter?

Thanks!
 
Last edited:
Yes start with the fuel filter first and try using a genuine one, also ensure it’s bled properly first.

You’ll need 16901RJLE01
 
Need to take it out for a proper spin but so far so good, previous filter did not look very clogged but it was an off brand one. Looks like a genuine Honda filter sorted it out. The access is an absolute nightmare though, my back is really not happy and my forearms look like a self harm attempt was made.
 
@F6HAD No dice, seems to take longer to trigger the CEL now but still does it. What's the next step in diagnosing? Fuel rail relief valve and injector leak back test?

It's definitely something dropping rail pressure over time under heavy load, takes a couple seconds of high demand to trigger the CEL. No problem with starting hot or cold which would be the usual tell-tale of a bad relief valve.

Edit: Idled the engine for about 30 seconds, fuel is leaking past the relief valve at idle.
20260917_224122~2.jpg
 
Last edited:
Injector corrections tested OK, logged fuel rail pressure and noticed the following:

Upon pressing the pedal fully rail pressure will spike and then quickly come back down and throw a CEL. This happens both WOT at high RPM (takes longer for the pressure to drop) or even quarter throttle at low rpms (near instant).
Will replace pressure relief valve and test again.

Fuel pressure regulator is at 42% duty while idling @ 300bar. Can anybody compare with a healthy CN1?
 
Last edited:
150k miles, pretty much only MOT certificates and some repair work to pass invoices. It's done less than 5000 miles since 2024.

Cleaned fuel tank strainer and still no dice. Priming bulb is not getting sucked in (returns to shape) when squeezed with the engine held at 3000rpm. Fault is entirely dependent on throttle position - the higher the revs the more throttle input and the longer it takes for rail pressure to drop enough to trigger limp mode. Fuel pressure regulator solenoid passed the test in HDS okay.
Leaning towards pressure leaking out into the return from high pressure side. Plan is to replace faulty pressure relief valve then test for injector leak back and decide from there - if leak back is excessive replace faulty injector(s), if not replace HPFP with a known good used unit.

If that fails then I'll need a pro to diagnose it.
 
Last edited:
Fuel rail pressure lower than expected (commanded).
Cap off makes no difference.
ECU, no idea - but when it doesn't cut off it goes like **** off a shovel, so there is a chance.

1st pull in second gear, foot to the floor, no CEL. 2nd pull in 4th, foot to the floor, CEL after a few seconds.
 
I would also suggest FPR valve. I’ve even seen someone fit an incorrect one off a Nissan (because it visually looked the same) and have a similar problem, not realising they have different internal spring rates.
 
You must log in or register to reply here.
Top