Rough idle once hot - VIDA help

[Decky62]

The car runs no better with the map taken off. Injectors are factory. I took it off to save on fuel and to lessen the damage until I get this sorted. I keep thinking it’s something to do with the PTC heater. I’ve noticed that with ac off and using the fan the higher you have the fan the better it runs. But it does run far better with the ac and fan on. Could it be a grounding issue?

I’ve downloaded PxTool to try and flash the ECM/CEM but I’m still at the decoding stage at the mo.

Also does anyone have any info on the oil separator/crankcase ventilation? I’ve done short journeys for years and wondering if it could be that

[Simmy]

pcv is always worth changing / cleaning its a basic starting point. i think messing with the cem will end up with a world of more problems if your trying to save fuel i think you may have the wrong car . as these cars are not known known for being frugal with fuel in any guise have you read the cem and ecm with the advanced tab in vida?

[Decky62]

I only took the re map off to save fuel, I was travelling back and forth to the beacons at one point but I’m not now. I don’t think the D5 is that bad on fuel really. Yeah I have checked CEM ECM on Vida in advance tab but there’s nothing you can do with it there. I think it can be done through Vida if you have a proper subscription and purchase the updates but I can’t work out how to do that.

I’m still not sold on the re map causing the problem but I wanted to try and rule it out by remedying it. I’ve had the remap on for as long as I’ve had the car. I’ve had it 6 years and it’s only in the last year or two this problems arose

[Simmy]

dealer level vida can do lots of things that clone vida cannot maybe you need to access this through an independent volvo specialist to keep down your costs good luck with your problem hope you get sorted soon

[Decky62]

Thanks for your help. I could just ask someone else to sort it for me but I like to learn, fiddle and make things worse along the way!

[Simmy]

have you cleaned the maf sensor have you done a leak back test on the injectors sorry for any confusion on fuel comments as i thought you were running a petrol version d5 is reasonable on fuel . what kind of mpg are you getting round town it might indicate if you have an over fuelling issue .ps always read current code off the delivery tab not the initial state tab.

[Decky62]

I put a brand new Bosch MAF sensor on a month or two ago. Cleaned the oil separator yesterday and it was pretty spotless. Fitted a new oxygen sensor. It runs better but the rough idle is still there. I haven’t got the proper set up to do a leak off test. I have ran them on Vida and the results are here somewhere. It wasn’t doing it at the time though as it wasn’t up to temperature. Computer reads 42mpg, I work it out to be 36mpg. I’ve always done short journeys but do have a blast now and again. I wanted to get this issue sorted before I put the remap on again. I miss the power!

[Simmy]

your round town mpg seems a bit low have you cleaned out the egr and connected pipe work ?. its fairly easy to make up a leak back test kit 5 small bottles or jars and some tubing follow si robbs video on youtube.

[Decky62]

I’ve cleaned the egr after the throttle, whist in place. I’ve never taken it all off as it’s a big unit. I have got a secondhand one here so I can see how to remove it. When I’ve got a spare day it will be the next thing to come off. I have seen the test with a pipes and bottles. I will construct one! I’m still thinking it’s an earth/ground problem. I’m going to video the issue I have and il post it up here.
I thought 36mpg was about right for short journeys here and there. Cars at 203k now!

[Decky62]

https://youtu.be/FZRJyjcLBkc