Vauxhall Combo D CDTi 1.3 ecoFLEX - Non start when hot, code P068A #
Posted by Andrew Windle on September 8, 2017, 9:27 pm
Year of Manufacture *: 2013 Engine Size and Code *: 1.3 - LN9/A13DT - 263A2.000 ( Optional ) ECU Type: Magneti marelli 8F3 ( Optional ) Scanner Used: Solus Pro ( Optional) Fault Codes: P068A- battery disconnection
Hi People, Need some help with this van. The van has been brought into me from a van dealer with a non starting fault from hot. The van was bought as a non runner with the head removed and all the bits were in the back of the van.The customer (an experienced mechanic)could not see any obvious reason why the cylinder head had been removed, so replaced the head. The van started without any problems and ran up to full temperature- all fine. The van was then switched off, left for half an hour, but on return failed to start. The next morning the customer tried the van again and it started straight away without any issues. Once warm, the van failed to start again. Having a number of similar vehicles at his disposal, he started the parts darts approach to diagnostics- without any success. He has changed: fuel pump, injectors, air flow sensor, MAP sensor, coolant temperature sensor, glow plug control relay, ECU/key,in tank fuel pump, fuel filter housing, fuel rail (I think that is everything) Nothing has either improved it or cured it. This is where I have got involved. What I have worked out is that though this is a temperature related fault it is not actually a physical temperature fault- and it only happens at a very precise temperature- 39C or over. If the vehicle is physically hot and with the aid of a potentiometer if you convince the ECU the engine is less than 39C the van will start perfectly. Which leads me to think that it is a fuel strategy issue. On live data in a non starting state I can see actual fuel pressure and desired fuel pressure are matched and if you scope the injectors you can see the injectors being fired, but it will not start- it does not even attempt to start. If you give it a tiny sniff of easy start she fires straight up and runs. When it won't start, occasionally the only fault code is P068A. I was starting to think it's a ECU fault but as it has been replaced for a known good one, it rules that out. I have checked all powers and grounds into the ECU starting and not starting state.I have searched all over the internet for some information on the fuel strategy for this system because I believe it is allowing too much fuel to return to the tank when it thinks it is hot. However, I am not sure how to prove this. I know it is wrong to assume but, I believe it is not a mechanical issue because it runs well when it is physically hot or cold, but to contradict this I have also discovered that the air flow desired and actual have a slight difference between them. To solve this I have checked the timing, blanked the EGR valve off and disconnected the exhaust which has made no difference.This discrepancy is still there whether it starts or not.
There are probably things that I have forgotten to say, but hopefully I have covered the main bits. I have got live data in a running and non running state on shop stream, if I need to refer to any data. Sorry this is a bit of a higgledy piggledy post, I have had this van for so long and checked so much I am starting to loose track of what I have done and what he has changed. I am not after a silver bullet just a guiding hand to get this van out of my workshop! Cheers, Andrew
Re: Vauxhall Combo D CDTi ecoFLEX - non start when hot
Are you sure that the battery and starter system are in good order? If it starts with a shot of brake cleaner it could mean that a minimum hot cranking speed is not reached by the starter system. What happens when you bump start it?
Re: Vauxhall Combo D CDTi ecoFLEX - non start when hot
Hi David, the battery is new and the start is good something else that has been changed. I've even had the battery on charge with the jump pack just in case. I've not bumped started it, but it will start hot or cold if you trick the ecu to thinking its cold
Re: Vauxhall Combo D CDTi ecoFLEX - non start when hot
I had this on a combo a while back, though when hot the engine sounded like it was firing but wouldn't pick up. Found it to be the fuel filter housing, the there is a valve on the return in the bottom of the housing that was covered in dirt. Cleaned out and the van would start every time. Suspect the fuel was returning to the tank and not allowing enough volume of fuel to the injectors to start the engine.