[137dave]

Hi, i've just made my dad a profile and I'm posting this for my him so after this it will be him who is replying .
I'm going to word this post as if its him


I've been suffering from a cough at above 3000rpm. i can accelerate hard from low rpm but once it gets over 3k it coughs. if i keep trying to accelerate it dies and will cut out. If i slightly let off and just tickle the throttle it recovers.
If i leave it to die when restarted it will be in limp mode and won't go back to normal until i clear the codes. it also brings up the pgm-fi light whille in limp mode.

The codes that are coming up are
P1065 - manufacturer powertrain non specific
P0087 - Fuel rail pressure too low

The car drivers perfectly fine apart from the cough under load.

I've read many threads about the fuel filters and pressure relief valve.

I replace the filter with a genuine honda unit and also gave it a full service including cleaning the strainer in the fuel tank as it had a little bit of crap around it.
I don't know if it could be the pressure relief valve as i suffer from no starting issues and also it can start back up again straight away while warm.

The car has had a bad batch of fuel a few months back and i also found some water in the bottom of the fuel filter when i replaced it.
i think there was a very slight cough before the bad batch of fuel but it has definitely got worse since (my dad cant really remember 100%)

I've also had the car remapped which has made it very noticeably worse.

I've instructed my dad on his next tank to fill with v-power and also use redex to try and clear the system. the next things im thinking is the pressure sensor itself and then maybe the pressure relief valve.
Hoping its not the fuel pump!

Cheers for taking the time to read this.
Has anybody got any advice for my dad?
He has been a mechanic for 30 years but isn't the best on computers so please bear with him .

Thanks again

 

[Quacker]

If you cannot test the actual fuel pressure, I would suspect either the pressure regulator or the fuel rail sensor, as indeed you have mentioned.
It could be starved of fuel, so check the basics like the free flow of fuel from the tank to the high pressure pump that is free from air.
CR is far simpler than old rotary sequential injector pump systems, so if he is used to those, this should not give him/you anything to particularly worry about.

 

[137dave]

Hi there yes i can read the fuel pressure by getting a reading from the obd. the pressure drops from 2400psi to 1700psi when the problem occurs, lack of pressure on the fuel rail but what i don't know is why. any help would be appreciated,

 

[Jon_G]

It could be the pressure regulator solenoid in the fuel pump... I had to replace mine. But it's only a suggestion.

Best to get it connected up to a Honda diagnostic system and run the fuel pressure test routines.

BTW, P1065 = fuel pressure lower than expected.

 

[Jon_G]

It could also be the rail valve 'letting go' under pressure, rather than a permanent leak that often causes starting problems.

I think your pressure readings are well out? Peak pressure is 1600 bar and the minimum target pressure when starting is 300 bar (so around 4500 psi).

 

[Damien Pole]

Did you solve the problem I'm getting same problem iv changed the fuel filter 3 times no air no leaks I'm about to take the Injectors out and send them for testing unless I find another cause for the problem so any help would be much appreciated thanks

 

[Jon_G]

Did you solve the problem I'm getting same problem iv changed the fuel filter 3 times no air no leaks I'm about to take the Injectors out and send them for testing unless I find another cause for the problem so any help would be much appreciated thanks

You don't need to remove the injectors to check if their leak-back volumes have become excessive, in fact it's an easy DIY if you leave them in place (and removing injectors can be a real pig!). Simply re-route the leak back return pipework on top of the injectors so that each injector 'feeds' an empty 2L Coke bottle, then run the engine until a reasonable amount has collected in each container... if any is significantly above average then that injector may need replacing.

Are you also getting P1065 and/or P0087? Were all these replacement fuel filters genuine Honda units made by Denso?

Have you checked that the rail valve isn't leaking? That's far more common than an injector problem.

 

[Damien Pole]

Thanks for your reply the first one was bosch filter then both have been genuine honda filters at a cost of £48 only reason I mentioned injectors was because iv had the car live tested? And the guy said injector 3 was not self adjusting(what ever that means) but that might not be the cause of my problem.

Yes I'm getting both p0087 and p1065 but I have to rule the filter out as this is now a second genuine one fitted and there was no leaks on the test and it's fitted correctly.

I did do a vale check on the pressure valve and got no fuel at all but maybe the valve is fine under tick over but when put through it's paces it might be leaking? I'm not really sure but I have no starting issues she starts 1st time hot or cold, but sometime I do get a higher idle speed but is not very often and soon returns to normal after 10 or 15 seconds but any suggestions are welcome thank you

 

[Jon_G]

Those codes both relate to the rail pressure being low. Less likely reasons are...
Restriction in the fuel line
Restricted fuel filter (which you've ruled out)
Dodgy fuel pump
Sticking fuel pump m-prop solenoid

More likely reasons are...
Leaking rail valve (try driving around with the output line diverted into a bottle?)
Injector leak-back has become excessive.

I'd recommend that you crack on and test this last thing! The live test refers to the injector operation, specifically how balanced the delivery into the cylinders is, based on individual piston force/speed at idle. As you probably know, injectors are calibrated and have an IQA code that is entered into the ECU to make sure they all work equally. However the Bosch EDC16 ECU will additionally 'trim' the injector fuel delivery to give an equal measured balance, up to ±5mg per injector, and that trim figure is what the live test shows. But just because the trim figures are in range, it doesn't mean that the leak-back volumes haven't become excessive!

 

[Damien Pole]

Those codes both relate to the rail pressure being low. Less likely reasons are...
Restriction in the fuel line
Restricted fuel filter (which you've ruled out)
Dodgy fuel pump
Sticking fuel pump m-prop solenoid

More likely reasons are...
Leaking rail valve (try driving around with the output line diverted into a bottle?)
Injector leak-back has become excessive.

I'd recommend that you crack on and test this last thing! The live test refers to the injector operation, specifically how balanced the delivery into the cylinders is, based on individual piston force/speed at idle. As you probably know, injectors are calibrated and have an IQA code that is entered into the ECU to make sure they all work equally. However the Bosch EDC16 ECU will additionally 'trim' the injector fuel delivery to give an equal measured balance, up to ±5mg per injector, and that trim figure is what the live test shows. But just because the trim figures are in range, it doesn't mean that the leak-back volumes haven't become excessive!

Thank you I will do both this weekend I shall test the rail valve while I take it for a quick blast and I will have a go at leak back test on each injector and see what I find but il post my resultsas it might help others again thank you

 

[Damien Pole]

Iv just fitted a brand new common rail valve and it made no difference but was worth a shot

I'm now thinking injectors because maybe at 3000rpm one or more is becoming blocked or not fully opening but I would of thought that would cause a high fuel pressure problem code but I keep getting low pressure codes?

Iv heard of a fuel sender in the tank could this be blocked?

I can get my hands on a set of used apparently working injectors for £90 or should I just get mine refurbished if they are faulty?

 

[Farqui]

Have you done any injector leak back tests yet?

 

[Damien Pole]

Have you done any injector leak back tests yet?

Not yet I am planning on doing it this weekend but my symptoms are only at 3000rpm or over so I'm not sure if it will show any signs? But I could be wrong

 

[Jon_G]

I don't like how you've abandoned performing diagnostics in favour of buying replacement parts.

 

[Damien Pole]

I don't like how you've abandoned performing diagnostics in favour of buying replacement parts.

I would only be buying them to replace any of mine if they are not repairable or if the repair cost is high, I am planning on doing a leak test and then removing the faulty injector/s and sending them off to be tested but at the same time if I buy the other 4 I can also send them away its only £10 per injector to test and if they could fix mine and tell me the other 4 are good I could sell them on or keep as spears

 

[Farqui]

Removing injectors is not a simple job and could quickly escalate your repair costs.

Good luck and pet us know how the leak back test goes.

 

[Damien Pole]

Have not had time yet to do a test but will do one tomorrow one thing I have noticed is a lot of either diesel or oil all over the back of my tailgate it smells like diesel and must be coming from the exhaust.

The car smokes a little bit if going full throttle but no more than other diesels, it use to smoke alot more when it had a copy air filter but I changed it to a genuine honda one a while ago. Do you guys think this could be due to a faulty injector? I am going to get the rest done tomorrow iv now got all bits needed so hopefully that will tell me something

 

[Farqui]

Dodgy EGR's can cause smoke, oh the joys of diseasel's.

 

[Damien Pole]

Dodgy EGR's can cause smoke, oh the joys of diseasel's.

Egr is mapped out and blanked and I can't see anything else other than injectors to cause diesel to come through the exhaust, il test them tomorrow and if they are ****ed il try and take them out fun time

 

[Damien Pole]

Did a leak back test today injector 1 and 3 had slightly more diesel but nothing bad but I did notice number 3 had bubbles coming out all the way through the test? But the amount of diesel that came out was within limits, I was hoping one or more would show more fuel and that would point to a fault but I'm not sure now