Black soot mark on starting and gearbox issue

[Dave Mason]

Some of you may remember me posting last year about 2013 Spain built YD25 auto and the issues I have had with it.

I have had turbo issues and injector issues, forced a turbo rebuild and an engine rebuild soon after, then the turbo vanes seized soon after it was reassembled from soot. I have just had it redone again by I am told the best turbo guys in my home city, Durban, South Africa. My truck has stood for 3 days while I had the flu, and when I started it this morning, I had this soot mark. (see attached picture) It did the same just before the vanes seized the last time. What could cause that?

Further and since the above, I believe my 2013 VSK Navara YD25 D40 Automatic has an intermittent fault within the auto-box valve body unit. I had the torque converter redone but it still has shuddering at low/ Idle speed in drive and reverse, and the gearbox goes through the gears very quickly when under load/ uphill and then battles to kick down and labours badly. Anybody ever experienced this?

Could this possibly be a fuelling problem (Soot in picture) that causes one of the sensors to send an incorrect signal to the ECU (Over fuelling or under fuelling) and that causes the gearbox to react inconsistently?

No faults showing through OBDII scan

 

[Dave Mason]

Since my post, on leaving my workplace yesterday, the car was excessively hoppy and seemed to be in limp mode driving home. I had my Torque Pro activated on my mobile and tried to read codes. I said something like "P1025 -fault code imminent" or "P1025 -fault code processing" like it was still trying to work it out. I cant remember the last word. According to the net, P1025 - is the Exhaust Oil Feeder Control Valve System. Where would I find that? Strange one.

So I was planning to ride the bike today, and then I thought let me start the truck and see if the code has been established. ECU clear, no fault found, drove to work, did a longer run then normal and checked for faults after. Nothing.

Car was a little hoppy but nothing like yesterday.

I seem to be the only person on this forum that has had this. Not one response

I am stumped, figuring its a sensitive sensor or 2 causing this issue intermittently.

Problem is that this causes excessive carbonisation looks like that effects the operation of the turbo and ultimately causes it to fail... I cant afford a third round with the turbo or an injector, so its going to someone Tuesday next week to do a deep dive. I am told he is a diesel specialist so lets hope.

Regards

Dave

 

[Dave Mason]

I also see it could mean faulty Fuel Pressure regulator valve

 

[bringthenav]

I also see it could mean faulty Fuel Pressure regulator valve

I get startup soot lately.. trucks sat for months with a blown clutch, excessive fueling, always blowing bit of black smoke on move off at lights or heavy acceleration.

i hear fprs do go & cause this stuff, cheap enough and easy to get to for replacement, i have one sitting there to chuck on after i get my clutch fixed.. hopefully it sorts my problem.

I get codes in similar way... lately ALOT and then & they clear during the drive or next drive are gone also random limps (but i aint got a reader that works yet... might try buying what u use & I'll try get back in reply what code i get)

I also have had limp mode alot before ...
caused by a soft old stock primer getting air in it... I FIXED IT
& by the water purge release on the fuel filter being slightly not tightened enough...
I FIXED IT

Both solved by modding to a new aftermarket fuel primer bulb thats a thicker product & aluminium joiners done up with clamps so no air can get in the one way primer hose.

The water purge dial on the fuel filter i got was slightly loose to the actual filter, not the bit u undo but the whole dial... i tightened it up carefully clockwise with some pliars with a rag over it just enough it cant move by hand like it was & without stripping it.

I WAS GOOD FOR A MONTH OR SO AFTER THAT, BUT THEN IT WAS BACK AGAIN LIMPING .. see BELOW...

I have had limp modes caused by slight boost leaks too.. at the outlet of the turbo to the baffle is main culprit!! . stronger clamps seemed to solve that!!
But its under so much pressure, oil can leech under pressure under the clamps & boost will leak just slightly under hard accel & limp mode can be triggered,
or if not that just a bit of power loss.

Slightly Sticking Suction Control valve also i reckon THE MAIN CAUSE AROUND for these occasional limp modes to come on usually under a heavy Accel for example overtaking someone & punching it.. on freeways or highways, which is so not fun & ive nearly been cleaned up by trucks or cars a few times, when i am suddenly going 70& trying to pull over to a freeway shoulder. Scary stuff & BAD problem to have.
Im HEAPS over it as well !!!

The concensus seems to be in this group... REPLACE the Suction control Valve (SCV) & the FPR. Solves limps, solves running rich, and startup or moving off lights or during acceleration is a sign .. as well as blowing clouds of black smoke all signs its running rich... also costs heaps more on diesel whenever any of the above happens with my Navara. It comes good for a 1000km or less if i add injector cleaner or fuel sys cleaners to the tank, but then comes right back, i got a sticky scv i reckon.

These replaced seem to solve black soot,
reducing it back to just some smoke.. startup and off light's etc.. but it's running too rich and using alot more diesel...
and the limp modes now back...
(Which many call False Limp Mode), as it goes away after u turn the car off and start it back up again usually.. and actual limp mode i think have a code and not go away.

Any limp modes bad though & so are codes and so is using heaps excess diesel, smoke under accel, start up soot, and the damn codes aren't aby good either.

Definitely changing both my SCV & FPR !
Try that would be my suggestion.

PS mate.. after changing both ..disconnect neg battery terminal & put ur foot on the brake pedal for 20seconds. Reconnect the battery, youve just reset the ecu & fuel system the easy way without having do the pedal dance of fun...go for a mild drive around town for at least 15-30min while the truck relearns your driving and acceleration habits. Then pull up & turn the car off & remove the keys. Even lock it and then unlock it & start it up and drive around another time, as once u turned it off after the reset, it should have finished relearning.

The ecu & fuel system will have relearned and adjusted to the new SCV & FPR.

I think its highly important and essential to do this reset after these get replaced going off other posts I've seen.

Give replacing these two a go i reckon champ & doing the reset, hopefully your issues will be gone. Let us all know if u try it & it solves it.

I know i gotta do it to mine after i do a clutch first Best luck

 

[Dave Mason]

I get startup soot lately.. trucks sat for months with a blown clutch, excessive fueling, always blowing bit of black smoke on move off at lights or heavy acceleration.

i hear fprs do go & cause this stuff, cheap enough and easy to get to for replacement, i have one sitting there to chuck on after i get my clutch fixed.. hopefully it sorts my problem.

I get codes in similar way... lately ALOT and then & they clear during the drive or next drive are gone also random limps (but i aint got a reader that works yet... might try buying what u use & I'll try get back in reply what code i get)

I also have had limp mode alot before ...
caused by a soft old stock primer getting air in it... I FIXED IT
& by the water purge release on the fuel filter being slightly not tightened enough...
I FIXED IT

Both solved by modding to a new aftermarket fuel primer bulb thats a thicker product & aluminium joiners done up with clamps so no air can get in the one way primer hose.

The water purge dial on the fuel filter i got was slightly loose to the actual filter, not the bit u undo but the whole dial... i tightened it up carefully clockwise with some pliars with a rag over it just enough it cant move by hand like it was & without stripping it.

I WAS GOOD FOR A MONTH OR SO AFTER THAT, BUT THEN IT WAS BACK AGAIN LIMPING .. see BELOW...

I have had limp modes caused by slight boost leaks too.. at the outlet of the turbo to the baffle is main culprit!! . stronger clamps seemed to solve that!!
But its under so much pressure, oil can leech under pressure under the clamps & boost will leak just slightly under hard accel & limp mode can be triggered,
or if not that just a bit of power loss.

Slightly Sticking Suction Control valve also i reckon THE MAIN CAUSE AROUND for these occasional limp modes to come on usually under a heavy Accel for example overtaking someone & punching it.. on freeways or highways, which is so not fun & ive nearly been cleaned up by trucks or cars a few times, when i am suddenly going 70& trying to pull over to a freeway shoulder. Scary stuff & BAD problem to have.
Im HEAPS over it as well !!!

The concensus seems to be in this group... REPLACE the Suction control Valve (SCV) & the FPR. Solves limps, solves running rich, and startup or moving off lights or during acceleration is a sign .. as well as blowing clouds of black smoke all signs its running rich... also costs heaps more on diesel whenever any of the above happens with my Navara. It comes good for a 1000km or less if i add injector cleaner or fuel sys cleaners to the tank, but then comes right back, i got a sticky scv i reckon.

These replaced seem to solve black soot,
reducing it back to just some smoke.. startup and off light's etc.. but it's running too rich and using alot more diesel...
and the limp modes now back...
(Which many call False Limp Mode), as it goes away after u turn the car off and start it back up again usually.. and actual limp mode i think have a code and not go away.

Any limp modes bad though & so are codes and so is using heaps excess diesel, smoke under accel, start up soot, and the damn codes aren't aby good either.

Definitely changing both my SCV & FPR !
Try that would be my suggestion.

PS mate.. after changing both ..disconnect neg battery terminal & put ur foot on the brake pedal for 20seconds. Reconnect the battery, youve just reset the ecu & fuel system the easy way without having do the pedal dance of fun...go for a mild drive around town for at least 15-30min while the truck relearns your driving and acceleration habits. Then pull up & turn the car off & remove the keys. Even lock it and then unlock it & start it up and drive around another time, as once u turned it off after the reset, it should have finished relearning.

The ecu & fuel system will have relearned and adjusted to the new SCV & FPR.

I think its highly important and essential to do this reset after these get replaced going off other posts I've seen.

Give replacing these two a go i reckon champ & doing the reset, hopefully your issues will be gone. Let us all know if u try it & it solves it.

I know i gotta do it to mine after i do a clutch first Best luck

Thanks BringtheNav, much appreciated