Pd150 Arl bad fuel economy after fast road camshaft install

[Leonpd150]

Hey,



I have had camshaft problem, one of the lobes has developed a flat spot. So I decided that i should install fast road camshaft from darkside development and rebuild the whole head because i want to exceed 270 bhp in the future . Which included oversized inlet and outlet valves, harder return springs, and black top lifters, higher duration and lift camshaft and a remap. After re assembly of the engine i noticed a huge drop in fuel economy and a rough start on cold engine with some white smoke. Before a used to get 36mpg and idle fuel economy was around 0.7l/h , now i get 26mpg and idle fuel economy is somewhere between 1.2l/h and 1.6 l/h . Since the head work i have tried changing coolant temp sensor , fuel temp sender and i have re adjusted distance between rockers arms and injector ( to the point where you feel noticable resistance then 180° back) before this work fuel economy was 18 mpg and idle fuel economy 2.2l/h . I have done a full VCDS Scan no error on engine module. We don't know what else to do , Darkside development states that they would expect a slight drop in fuel economy but not that much, my tuner adjusted SOI accordingly and torsion value is 0.6° - 1.1° which is spot on according to dark side development.
This is a 1.9 TDI ARL engine that has been remaped before head work and was running somewhere around 200 bhp and fuel economy actually grown since the first remap. But now it's gone downhill.
I don't know what else to do then seek help form forums , i have VCDS so if any of you have a suggestion what should I log and in which conditions so we can resolve this fuel economy.
Thanks in advance,
Hope to hear from any of you soon.

 

[Nam-uk]

adding any custom upgrades like that you'll need a custom remap, a generic wont cut it
my generic map i get around 36mpg as you do unless i go on motorway in 6th were it goes higher, mines standard engine as well

 

[Leonpd150]

I know the remap was done but probably by an **** tuner who doesn't know how to tune a map property . Maybe 5% of tuner in croatia know only how to buy a generic map and flash it to the ECU but all of them will say that they can do a custom remap take your money and act dumb later on ... Sory for the rant .


Before this camshaft upgrade i was getting 36 mpg which is ok for me but everyone tells me that is low too. I was running about 200 bhp.

 

[smutts]

I was chasing poor mpg recently, had a thought while on a long straight road,
pulled into a layby, felt the wheels & one was warmer than the others.
It was a rear brake pad rusted tight on the carrier.
On sorting, my average mpg @ 70mph (GPS) went from 45mpg to 55mpg.

Just a thought, as your car might have been sat a while whilst getting sorted.

 

[Leonpd150]

That wouldn't explain bad fuel economy at idle

 

[Rich.T]

A pure guess.
But arnt they part mechanical injectors?
Longer duration cam = injectors are also possibly open longer too?

 

[Leonpd150]

Yes that is right but not that much. This engine with GTB turbo kit and bigger injectors and some other mods can get up to 450hp and with that setup the engine doesn't have this low fuel economy.

 

[smutts]

That wouldn't explain bad fuel economy at idle

Surely all fuel economy at idle would be zero mpg?

 

[smutts]

Not an expert on the PD engines, but it's diesel, so no faffing about with mixture ratios, oh the joys of carburettors.
So, if........ good nozzles, good injection timing, no air in fuel, good filters, good breathing, good compression, ( & no dragging brakes ), then a diesel will do the mpg as advertised.
I assume torsion values are the cam advance, is the start of injection fixed by the cam & stop of injection is by the solenoid?
Or does the cam ram the plunger down in the injector, and the solenoid closes the leakoff for start of injection, and opens the leakoff to finish injection?
Just asking for an idiot who has little idea of PD engines, i.e. me!
Is the crappy mpg from the display, or actual miles per tank fillup litres times 4.546 for mpg?
My guess would be poor timing data from somewhere.

 

[rafletcher]

Surely all fuel economy at idle would be zero mpg?

Leonpd150 quotes the fuel flow rate at idle, and it’s high.

 

[smutts]

Are VCDS block 13 values sensible? with no outliers?

Ghetto test, if you have a steep quiet hill, (15% to 20% grade is ideal for diesel), park, engine off, steering lock off, pointing downhill, put in first gear with foot off clutch, release handbrake. Count how many seconds for each cylinder to leak down and the car to jerk forward to the next cylinder.
A new engine you would get bored counting. 20 seconds great, 10 seconds good, 5 seconds meh, 0 seconds bad news.
All the usual caveats apply, don't sue me after the accident if it all goes tits up!

Was there a valve job?
Could the contact between the valves & seats been overlapped (overcut) reducing the contact pressure & allowing them to leak & lose compression?

Not familiar with PD nozzles, but the computer is deciding to stuff a lot of fuel into that engine to keep it turning. at least that is what it is saying.
Could much of that fuel be leaking up the nozzle pintles if they're worn or misfabricated and returning by the leakoff pipework to the tank?
Does the real world fuel consumption match what the computer thinks is happening?

Could the camshaft be misground? With the fuel cams retarded relative to the valve cams?

Good Luck.

 

[smutts]

For those watching the rain this sunday, some reading material

 

[Leonpd150]

Are VCDS block 13 values sensible? with no outliers?

Ghetto test, if you have a steep quiet hill, (15% to 20% grade is ideal for diesel), park, engine off, steering lock off, pointing downhill, put in first gear with foot off clutch, release handbrake. Count how many seconds for each cylinder to leak down and the car to jerk forward to the next cylinder.
A new engine you would get bored counting. 20 seconds great, 10 seconds good, 5 seconds meh, 0 seconds bad news.
All the usual caveats apply, don't sue me after the accident if it all goes tits up!

Was there a valve job?
Could the contact between the valves & seats been overlapped (overcut) reducing the contact pressure & allowing them to leak & lose compression?

Not familiar with PD nozzles, but the computer is deciding to stuff a lot of fuel into that engine to keep it turning. at least that is what it is saying.
Could much of that fuel be leaking up the nozzle pintles if they're worn or misfabricated and returning by the leakoff pipework to the tank?
Does the real world fuel consumption match what the computer thinks is happening?

Could the camshaft be misground? With the fuel cams retarded relative to the valve cams?

Good Luck.

First and third injector have some correction first is at -1.6mg/stroke and third is 1.4mg/stroke which is inside tolerance but it could be cause for bad fuel economy . Head was completely rebuild with FastRoad camshaft from darkside development new oversized valve from darkside development and titan return spring also form darkside development . All injectors have new seals and all the seats are newly cut. So the head shouldn't be a problem, that engine has great compression isn't burning any oil and has great power. And real world consumption does match what computer says.

Since i have last posted i have done a remap and readjusted injectors. The car is now starting great but there is still come white smoke coming out of the exhaust on cold starts. And now idle fuel flow is a little better but still high before remap it was about 2.2 l/h now it varies from 1.2l/h to 1.7l/h and i don't know what it oscillates like that i stop at a read light it's 1.7l/h 10km later i stop again it's 1.2l/h i will do the test you recommended and will post the results tomorrow . Here are few logs i have already done just glance at them and see if you spot anything out of the ordinary.

LOG-01-004-007-013.CSV

drive.google.com

LOG-01-003-004-011long.CSV

drive.google.com

usp=drivesdk

LOG-01-003-004-011short.CSV

drive.google.com

 

[BigJase88]

Surely all fuel economy at idle would be zero mpg?

Yeah would concur

 

[Leonpd150]

Yeah would concur

I specified the flow rate at idle . It is 1.2l/h - 1.7l/h

 

[smutts]

I have to confess that I am out of my comfort zone fiddling with engine management.
My gut feeling is something is screwing up the injection timing, causing it to be retarded.
Air bubbles in the fuel supply might do this.
Perhaps a duff, or noisy signal from somewhere is giving the computer a hard time.
Good luck, as I'm out of my depth.

 

[Leonpd150]

I have solved this problem. The foult was in Darskside Development camshaft which was very low quality camshaft . I have swaped it with 276 camshaft from FCP and car works great . Now Darkside development is blaming me that i put in wrong spec oil (I didn't i always use OEM Castrol oil) or that camshaft wasnt lubed correctly upon installation (I am sure that it was camshaft was installed by very experiance machining shop). Upon installation camshaft blocked(at which point in time a should have returned it) in the head it turned out that spots where camshaft seats on bearing weren't the same in diameter the differences were about 0.02mm remachined this camshaft and the in was spinning freely.

DO NOT ORDER FROM DARKSIDE DEVELOPMENT THERE ARE BETTER PRODUCTS FOR LESS MONEY AND AS SOON AS SOMETHING GOES WRONG THEY JUST SAY IT IS YOUR FAULT WHEN IN CLERLY ISNT

 

[BigJase88]

I have solved this problem. The foult was in Darskside Development camshaft which was very low quality camshaft . I have swaped it with 276 camshaft from FCP and car works great . Now Darkside development is blaming me that i put in wrong spec oil (I didn't i always use OEM Castrol oil) or that camshaft wasnt lubed correctly upon installation (I am sure that it was camshaft was installed by very experiance machining shop). Upon installation camshaft blocked(at which point in time a should have returned it) in the head it turned out that spots where camshaft seats on bearing weren't the same in diameter the differences were about 0.02mm remachined this camshaft and the in was spinning freely.

DO NOT ORDER FROM DARKSIDE DEVELOPMENT THERE ARE BETTER PRODUCTS FOR LESS MONEY AND AS SOON AS SOMETHING GOES WRONG THEY JUST SAY IT IS YOUR FAULT WHEN IN CLERLY ISNT

I had a dbilas dynamics in my pd130

No issues with that

 

[Leonpd150]

yes dbilas is good quality product

 

[smutts]

Assume nothing, sadly.