Crank no start...but then does...
- Thread starter Ninj43
- Start date
As seen above in post #61 for a successful start-up the registerd air mass was significantly more - even cranking speed was significantly less - 170 RPM.
For the non-start (post#54) cranking speed was 280 RPM- possibly because of well charged battery. But still mystery why the registered air mass was so low.
Unless I'm interpreting wrongly - it seems that in post#54 the throttle valve was closed thus preventing engine getting air (and therefore engine being capable to cramk much faster). Should have thrown fault code though
Not sure why ECU would ever close the throttle (rightmost red column) for start-up. Neither did the fuel pressure regulation work at all - possibly bleeding the pressure? Bad software??
Below a slightly modified parameter set for next start-up logging - in case it still fails to start. Throttle valve monitoring added (0%=fully open)
IDE00021 Engine RPM
IDE00347 Air mass: actual value:
IDE00352 Main injection: duration of activation
IDE00407 Rail pressure regulation: status
IDE00589 Fuel pressure
IDE05632 Fuel pressure regulator valve actual value
IDE05633 Valve for fuel metering: feedback value measured
IDE07771 Throttl.valve adapt. 1 bank 1: posit feedback - Actual value
IDE07822 Fuel pressure regulator valve: activation
IDE07824 Tank-internal presupply pump 1 bank 1: activation
ENG125965 HPV current demand coming from the HPV control
ENG125966 HPV current demand coming from the IMV control
Curious to see how things are different - could you please make another set of blockmap files 1) engine off 2) engine idling.
Mass air flow is an interesting point. After these logs (so if it was an issue at all, it would have to be intermittent at best) I was checking for loose fuses. Although not loose and not a recent addition, there was a piggyback fuse holder in SB20 Mass Air Flow Meter and ECU. Cant imagine it being a thing as surely if it was loose, it would shut the van down if it came loose. Anyway, I've put a fresh fuse in and removed the piggyback for now.As seen above in post #61 for a successful start-up the registerd air mass was significantly more - even cranking speed was significantly less - 170 RPM.
For the non-start (post#54) cranking speed was 280 RPM- possibly because of well charged battery. But still mystery why the registered air mass was so low.
Unless I'm interpreting wrongly - it seems that in post#54 the throttle valve was closed thus preventing engine getting air (and therefore engine being capable to cramk much faster). Should have thrown fault code though
View attachment 307111
Not sure why ECU would ever close the throttle (rightmost red column) for start-up. Neither did the fuel pressure regulation work at all - possibly bleeding the pressure? Bad software??
Below a slightly modified parameter set for next start-up logging - in case it still fails to start. Throttle valve monitoring added (0%=fully open)
IDE00021 Engine RPMIDE00347 Air mass: actual value:IDE00352 Main injection: duration of activationIDE00407 Rail pressure regulation: statusIDE00589 Fuel pressureIDE05632 Fuel pressure regulator valve actual valueIDE05633 Valve for fuel metering: feedback value measuredIDE07771 Throttl.valve adapt. 1 bank 1: posit feedback - Actual valueIDE07822 Fuel pressure regulator valve: activationIDE07824 Tank-internal presupply pump 1 bank 1: activationENG125965 HPV current demand coming from the HPV controlENG125966 HPV current demand coming from the IMV control
Curious to see how things are different - could you please make another set of blockmap files 1) engine off 2) engine idling.
I'll do some fresh block maps today, is there data from the above logs going to help you just now or one to keep in the bank for if the fault ever comes back?
I did give it a little throttle one time, more to see if the noise of the crank changed, it didn't make any difference to it firing up or the noise while it tried
Mine wasn't looking bad but not great so swapped it and cleaned up the posts as a precaution @Dellmassive @DXX - little over a tenner must be worth it for future peace of mind
Last edited:
ECU most likely would throw a fault code if the EGR valve couldn't follow commanded value. Unless the fault code had been blanked out.
In the blockmap files the EGR was recirculating exhaust gases (non-zero values)
Correct.
No, CXEB engine has only one EGR (the high-pressure one).
@mmi - Thanks so much again, great info, apologies, I forgot CXEB only has a single EGR
Was that in all the block maps that showed EGR movement? The first batch was under the EGR delete file, so resultant DTCs would have been inhibited from throwing up an EML, but if it was partially open and still active (I have seen that with an incorrect solution in the past) could it potentially stop the DPF from a regen? It never had blanks fitted on the assumption it was a good solution.
Was that in all the block maps that showed EGR movement? The first batch was under the EGR delete file, so resultant DTCs would have been inhibited from throwing up an EML, but if it was partially open and still active (I have seen that with an incorrect solution in the past) could it potentially stop the DPF from a regen? It never had blanks fitted on the assumption it was a good solution.
The thing that has me most bamboozled is, why with nothing done to the DPF would it not throw an EML when it failed to regen for over a thousand miles. Was that all just because of failed regens due to short journeys etc etc?
The differential pressure was way past the point of needing to tell someone - circa 160mb at 3000ish RPM and peaked at 720mb during a power run. At the point at which you spotted it hadn't regenned, soot was sat at 31g so potentially when I kicked off a regen in VCDS, it was about to do it itself.
The differential pressure was way past the point of needing to tell someone - circa 160mb at 3000ish RPM and peaked at 720mb during a power run. At the point at which you spotted it hadn't regenned, soot was sat at 31g so potentially when I kicked off a regen in VCDS, it was about to do it itself.
All blockmaps engine idling (green). Engine IGN ON - EGR is closed (0=no recirc)
I would have expected the ECU throw a fault code + dash DPF light etc. if something would have inhibited it to do a regen. Also an indication of something being seriously wrong were the zeros for soot calculated and soot measured (post #46)
Based on the data something was definitely done to the DPF regeneration process. Actually, in stock software there even might be a backup process to do a forced DPF regen after 750 km since last regen (in case everything else have failed) --> Multiple Engine Management Faults
Short journeys don't make engine to skip DPF regens - quite the contrary - would run much more frequent regens.
Gets more interesting by the minute then! Yes I agree, definitely something done to DPF to make it read 0 soot mass so that looks to me like 100% a bad solution for what should have been only EGR and AdBlue related.
When I was saying short journeys I meant, potentially short enough to end a regen once in progress, not the request. The van has been driven in a feast or famine situation, so lots of continual 5 mile round trips so never really getting up to regen conditions.
Sorry Im being a dunce, what do you conclude about the EGR, it looks to be active and following demand (ish) in the "EGR Delete" data as well as the stock condition? I would expect to see 0% actual if it was properly removed
When I was saying short journeys I meant, potentially short enough to end a regen once in progress, not the request. The van has been driven in a feast or famine situation, so lots of continual 5 mile round trips so never really getting up to regen conditions.
Sorry Im being a dunce, what do you conclude about the EGR, it looks to be active and following demand (ish) in the "EGR Delete" data as well as the stock condition? I would expect to see 0% actual if it was properly removed
Shouldn't be an issue - would eventually light up dash DPF light. Anyways, some experiments about short journeys --> [T6_measured] DPF regeneration vs. short journeys
Based on the data it seems to be working as normal, though not many data points. Yes, 0% would mean no recirculation. Perhaps it was meant to use blanking plates as quite a few fault codes were "suppressed" - obviously including DPF monitoring codes.
Possibly the most intriguing "modification" was the non-start issue in below - without any fault codes
Yep - I think we can surmise a total ar5e has been made of the option deletes here. I totally agree with the throttle valve too, thats mental. There is no explanation I can see why a map would intermittently call for the throttle valve to remain closed so I suspect an additional snag at play. Surely it would never have started from the time the file was swapped
Last edited:
So.....would it be worth removing the dpf and having it cleaned and then getting a new delete map installed by someone like Dav-tec to deal properly with the egr and ad blue?
Then hopefully you'll be back to normal dpf regen operation.
Then hopefully you'll be back to normal dpf regen operation.
