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TD42 DPC Module
Posted: 06 Apr 2017 10:12
by Rudolph
After a trip to Hogsback over the weekend, I have noticed the following on the TD42. On hard acceleration there is a lot of black smoke and on one occasion there were also some white smoke coming from the exhaust.
Black smoke is normally over fueling or bad combustion? White smoke should be vapor not sure about this one?
I have also installed the EGT gauge and the temp is varying a lot from 5th gear open road 100km/hr 2000rpm around 450deg, 4th gear 70km/hr 2000rpm 300deg. On acceleration it easily goes over 500deg, I have not got to 600deg yet.
The average diesel consumption for the weekend were 7.4km/l on the odo, I have not calibrated it on the GPS yet.
I have checked a few things and read up in the maintenance manual. The DPC module is removed from the car and the shut off is manual now with a cable as Andre had difficulty on switching of the engine, so the little wiper motor with the arm to the inline diesel pump is not functional. In the manual I see there is 3 positions for the DPC module, DRIVE, START and STOP.
My question now is what is the difference between the DRIVE and START position with regards to the inline pump, will this affect the black smoke/over fueling I’m seeing?
Is it possible to check if the DPC module is ok? Anyone out there that maybe have a DPC module and the wiper motor thing on the inline pump for sale to replace mine?
Re: TD42 DPC Module
Posted: 06 Apr 2017 11:02
by Tinus lotz
Dude all 4.2 make black smoke when they start ....Michael has one of those in his workshop. ...those egts are very low no need to worry about it some room for feul there make that NA go a bit better

Re: TD42 DPC Module
Posted: 06 Apr 2017 11:44
by Michael
Rudolph, the black smoke is not a problem really. If it is black it means that it did combust and burn. It indicates that the mixture is leaning towards the rich side, but nothing to be alarmed about.
White smoke on the other hand means the fuel did not burn and can be many things.
Your fuel consumption seems good so dont think there are major problems if any.
I am not very up to date with exactly how the inline pump must be set up, but it works in a totally different way than the rotary pumps.
Re: TD42 DPC Module
Posted: 06 Apr 2017 13:03
by Dustin
Rudolph, bear in mind that fuel consumption is from the ODO reading, but if I can remember when I saw the vehicle in André's workshop, it has 33" tires.
The additional rolling diameter will mean the tires are rolling up to 12% further than the ODO reading will show. I might be out with the percentage, but the easiest way to check is use your GPS to see how out the ODO is to the tires.
My last consumption before I started the turbo conversion was about 9km/L.
Re: TD42 DPC Module
Posted: 06 Apr 2017 14:13
by Michael
Dustin wrote:My last consumption before I started the turbo conversion was about 9km/L.
I hope you have said your goodbyes to that number

Re: TD42 DPC Module
Posted: 06 Apr 2017 14:20
by Dustin
Boost vs. Fuel consumption...

.... I CHOOSE BOOST
LOL
Re: TD42 DPC Module
Posted: 06 Apr 2017 14:26
by Rudolph
Tinus lotz wrote:those egts are very low no need to worry about it some room for feul there make that NA go a bit better
Michael wrote:Your fuel consumption seems good so dont think there are major problems if any.
Ok, so we saying that I don't need to worry about the DPC module not working and just drive it.
Dustin wrote: but if I can remember when I saw the vehicle in André's workshop, it has 33" tires.
It is 32" on R15's, on my 4.2 petrol GQ also running on 32" the odo vs GPS is pretty close almost the same.
Dustin wrote:My last consumption before I started the turbo conversion was about 9km/L.
That is awesome! So I have some room for improvement, getting the inline pump setup properly and maybe have a look at the injectors?
Re: TD42 DPC Module
Posted: 06 Apr 2017 16:25
by Wilkie
Rudolph wrote:Tinus lotz wrote:those egts are very low no need to worry about it some room for feul there make that NA go a bit better
Michael wrote:Your fuel consumption seems good so dont think there are major problems if any.
Ok, so we saying that I don't need to worry about the DPC module not working and just drive it.
Dustin wrote: but if I can remember when I saw the vehicle in André's workshop, it has 33" tires.
It is 32" on R15's, on my 4.2 petrol GQ also running on 32" the odo vs GPS is pretty close almost the same.
Dustin wrote:My last consumption before I started the turbo conversion was about 9km/L.
That is awesome! So I have some room for improvement, getting the inline pump setup properly and maybe have a look at the injectors?
Its always a good thing to have injectors tested ...provided the "tester" is ligit

Re: TD42 DPC Module
Posted: 06 Apr 2017 19:40
by Peter Connan
You seemed concerned about the EGT's changing rapidly.
This is perfectly normal. In fact' if this is not the case, you have a problem.
Re: TD42 DPC Module
Posted: 07 Apr 2017 08:37
by Rudolph
Peter Connan wrote:You seemed concerned about the EGT's changing rapidly.
This is perfectly normal. In fact' if this is not the case, you have a problem.
I'm happy with the EGT's, my concern is more towards the position of the inline pump at START and DRIVE when all is working and now it is either open or closed to start and stop, does it still pump fine as it is now is more my concern, should I worry or be happy
