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Loss of power across rev range

Evocarl

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Location
Portsmouth
Car
Honda Accord
Hi all, ok have a prob with my accord cdti, there is a significant loss of power across the entire rev range. Things I have checked already are bother the turbo and imrc solenoids, egr valve function ok and clean, no boost leaks, turbo vnt free and function ok turbo healthy, injectors ok been checked and cleaned, air mass ok, map sensor ok. General health of the engine is good no major mechanical probs. new genuine fuel filter, exhaust not blocked timing correct, not logging any fault codes. Most parts have been checked and substituted thanks to Adam aka the hole any ideas????

Carl
 
Not yet all the fuel side was checked at a bosh agent that I have used for years all ok, everything else swapped for known good parts no codes at all showing ordered hds so hope that can shed some light soon
 
just to add in some information to others.

this car feels like its dead honestly, no sense of power or 'urgency' when putting your foot down in any gear.

from 3k upwards there is no power and takes and age to gain rpm. almost like there is no turbo at all.
no smoke, so I doubt its a boost leak.

changed maf, inlet solenoid, map and turbo vac line solenoid from my car to his with no improvement.

it is almost pointing to no boost but we have no way to check until HDS arrives.
its perplexing and spent a good 2 hrs with this car changing parts and it still wasnt having a bit of it.

It was nice to meet you carl and will want to see you again if I can help in anyway as it was disappointing not to see the car run correctly.
 
I have had a generic obd reader on the car and was showing 35psi of charge pressure when driving under acceleration, weather this is over atmospheric pressure or including the 14 ish psi of atoms I don't know so could be roughly speaking 1 bar or 2 bar of boost pressure
 
Needs to go on a HDS for some further deeper diagnostics to check operation of individual components against Honda set thresholds

How did you check the movement of the VNT and eliminated that as a probable cause? and have you swapped over the MAP sensor too?
 
faddy. map sensor and maf sensor was swapped from my car to his.. made no difference to his car after installation.
my car works fine with my parts refitted.

it could be the vnt as the rev range is like this:
low down there is little to no pull.. must say it possibly felt slower than stock.
mid range till 3.5k there was more boost but it didnt hold and tailed off VERY fast leading to
top end.. it was like a donkey pulling the car along. no urgency from engine no obvious signs of getting and maintaining boost.
 
I have had a generic obd reader on the car and was showing 35psi of charge pressure when driving under acceleration, weather this is over atmospheric pressure or including the 14 ish psi of atoms I don't know so could be roughly speaking 1 bar or 2 bar of boost pressure
It's manifold 'absolute' pressure being measured (not 'gauge' pressure) so starting at a theoretical zero rather than the alternative baseline 1bar / 14.7psi atmospheric. So you appear to be getting around 20psi / 1.4bar of boost.
 
Movement of vnt is ok have full travel and the actuator is moving it ok no sticky spots at all,next step is checking components are within Honda specs
 
How is the fuel consumption? If it's 'normal to low' then it seems likely to be an under-fuelling problem, maybe due to low fuel rail pressure? OBD readings wouldn't pick this up if it's a faulty (i.e. over-reading) rail pressure sensor.
 
That's what I'm hopping to find fuel use seems normal and no smoke at all fingers crossed hds arrives soon!
 
Really the ECU should pick up low fuel pressure errors, but it depends if it's still somehow within tolerance at the point of measurement within the system.

My money is on either a knackered turbo or weak high pressure pump.

It can also be a bad injector causing this by the way - but again until a deeper diagnostic is done, it's all guesswork.

I'm probably down in Newbury next week one day if you want to arrange to meet up for a diagnostic.
 
Injectors have been checked by a reputable company who do all our Bosch fuel parts on mercedes cars and they are they same thing all ok, a weak high pressure pump should flag a code of some sort but I'm not ruling but I'm not ruling it out yet! And bit gain pressure first thing quickly and starts clean too.
 
And the turbo is only a mechanical item it's all within spec impellers and compressor wheels are damage free vnt clean and free has been checked already.
 
Injectors have been checked by a reputable company who do all our Bosch fuel parts on mercedes cars and they are they same thing all ok, a weak high pressure pump should flag a code of some sort but I'm not ruling but I'm not ruling it out yet! And bit gain pressure first thing quickly and starts clean too.
A weak HPP (or - just as likely? - a sticky internal pressure control valve) would eventually cause a P0087 DTC "rail pressure low" warning (also poor starting and maybe a P1065 DTC), but this wouldn't be the case if the fuel rail sensor (on end of rail nearest the battery) was faulty and giving a high reading... the ECU uses the output from this sensor as feedback to the pressure control valve in order to 'throttle' the diesel pump intake, so the whole system would then be running at too low a pressure, but wouldn't realise, and then the injected fuel would be too little. Unfortunately, if you were to connect diagnostic equipment then this would also indicate correct fuel pressure, as most diagnostic systems simply read the data given by the same sensor (unless the diagnostic equipment has its own independent sensor that gets connected to the rail). But I think there are are more likely explanations before replacing/testing the rail sensor and it does sound like you have access to garage facilities?

But if you do eliminate everything else, then I happen to have a complete fuel rail with sensor, etc that I know to be good.
 
Yeah I do have access to everything I need except hds at the mo! I've got the feeling that it is a fuel problem over anything else just from the sound of the engine so this will be the first point of checking I can get the pump checked again if needed and may need to sort something out regards swapping out fuel rails! Regards
Carl
 
carl if you need a local fuel rail sensor then you can use mine if its not too difficult to remove... well you can borrow mine ;).
 
Thanks Adam and no it's not hard easy and quick to just pinch the whole rail for a few mins lol will see how diagnostics go..........
 
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