Engine revs...hunting/surging

[Brett05]

As the heading suggests
I have this problem at the moment. I have always run BP and filled up last week with Caltex. Since then I have had this hunting of the engine revs. (this is what it sounds like.....rev.....rev.....rev.....rev..........) Manifolds have been replaced, some time back. New fuel filter a few weeks back....disconnected the chip today and still doing it, but not as pronounced. Checked all the MAP sensor wires, air cleaner element cleaned the same time as the fuel filter was replaced, along with a MAF clean. Manual boost control hoses are all connected ok. This has me trucked, because it only starts about 8-10 k's into the trip each day almost at the same part of the road. I have not checked the fuel filter as yet...probs do that tomorrow. The last time this happened was on my way out to Land Cruiser Park and I mentioned to Jo1234/Dad, when I got there that it was surging. This is the only two times I have filled up with Caltex....(you do remember that Jo....don't you.)

Any suggestions to cure this would be a great help
Brett

[motoz]

There was a post a while back regarding surging. Going from memory there are two small vac lines that go into a sensor on top of the manifold.

One has a white and the other a yellow trace. The fix involved putting a small bearing into the line with the yellow trace to block it off.

[Brett05]

There was a post a while back regarding surging. Going from memory there are two small vac lines that go into a sensor on top of the manifold.

One has a blue and the other a yellow trace. The fix involved putting a small bearing into the line with the yellow trace to block it off.

Yeah, I think I was the first to do this mod. The service manager did this for me whilst I was waiting for the lower manifold to arrive, after the upper had been replaced. I still have this mod in place.

[motoz]

Classic...

"Brett05 wrote:
back in April this year i had the upper inlet manifold replaced. All run smooth for a few weeks, then i had the surging again and the service manager at the local Mitsi Dealers took it for a drive and informed me the lower manifold will need replacing....will be a few weeks before we can do it. He then pointed out a to me a small hose that can be blanked off and this will stop the surging. He said to stuff a small bearing in there and away you go. Apparently it stops the signal to the suction control valve, and the surge wont be there. So i blanked it off and run for a few weeks like that....no probs at all. Few weeks later they replaced the lower manifold and i was very impressed with the outcome....until now. For the past week i have had a surge/flat spot under hard acceleration. Over the weekend i tried all the usual things to sus out the surging....found nothing.
So i tried the blanking of this little hose again and this has ridded my truck of the surging again. I know this means a trip to the dealers to have it checked out and fixed/replaced......so i thought i'd just share with you all the hose location and where to blank it off (as per instruction from the service guy)
Under the Engine cover, front right (looking at the engine from the front) is this solenoid with two black hoses, one with yellow stripes and one with white. Blank off the yellow one just above the solenoid. Now i don't know what this is for other than a supply to the suction control valve (maybe someone with a bit more knowledge than me would care to explain), but it has temporarily cured the problem"

I just went back and found the post you wrote...

[chaser]

suction control valve more than likely mate...

[Brett05]

suction control valve more than likely mate...

Chaser, I don't know much about this (SCV) and won't pretend to....as this is your field of work...can you tell me. If I have the hose blanked off to the suction control valve (done by the service manager at Mitsibushi) should that disable the SCV altogether, or does it still operate...?. I was under the impression that the mod disabled the valve.

[gregned]

I'm sure that this mod disables the swirl control valve as the SCV regulates fuel pressure

[coxy47]

Yeah two different systems the swirl control valve which is disabled by the ball bearing controls the airflow to combust better at idle or something along those lines. And im pretty sure gregned is spot on with the suction control valve.

[Tony]

Correct, there is a vacuum operated diaphragm that works the butterfly's in the lower intake, that may be what he blocked off.

The SCV, suction control valve... Is like a clever solenoid that allows more or less fuel to the common rail pumps high pressure side intake. On the triron, it works in rest in full open mode = 100% and when polarized cuts fuel back. The term suction control makes some think is related to vacuum.
It's on the supply side of the pump so doesn't get any fuel pressure against it. They can get weak and stick open or closed due to small impurities in our fuel. I have also seen the coil heat up due to sticking.
Sure can cause the surging as mentioned and will eventually make a cel if bad.

[SecondEye]

Also be wary of opening up the SCV to clean out. Due to the extreme pressures of the triton common rail diesel fuel system you may end up with a permanent leak or worse cut through something with a leak. And yes i have seen a bonnet cut open with the spray of fuel that comes out, it VERY high pressure.

[RHKTriton]

These things definitely run smoother with the swirl jigger disabled - I was getting a bit of surging in the morning sometimes and after killing this, I've had no more issues.

After reading about the Fuel system, I'd leave that to the "experts" , too many expensive bits to [censored] up!

Re the Caltex - I generally use it and the Freedom bio-mix and both good most of the time. I did have a couple of tanks from Caltex where you could tell it affected the engine - rougher idle, etc. On refilling with Freedom all good again. Recent Caltex also good.

[Brett05]

Thanks for all the help and info here guys
It appears I was getting my Sucks and Swirls mixed up.....my bad.

Drove to work this morning and it did the same thing as it has done all week. After work this morning, I began the process of elimination.
Air cleaner element cleaned and oiled.....check
MAF sensor cleaned again....check
MAP Sensor hose cleaned out....check
Manual boost control hoses.....check
Swirl Control Valve cleaned....check
Catch can emptied...(shot glass full of oil)....check
Re-installed Chip to T3 F2
took the SCV Mod (bearing in tube) out, went for a drive then re-installed it.

The surging/revving has gone, though I don't know if, what I cleaned/checked was the cause of it

Cheers
Brett

[Cam472]

I had my SCV replaced under warranty a few weeks ago now as Iv'e been going through what you have for the past 25,000km. Since having the SCV replaced Iv'e yet to have surging. Hope it's solved your problem too.

[chaser]

take to dealer and get fuel pressure checked, i sticking scv will cause erratic fuel pressure at idle. Which will cause the surge and rough idle...

[longsville]

Have read this whole post and believe i may be having a similar issue.
This morning on the way to work for some reason i had the radio off, took off from some traffic lights and then noticed that under acceleration rather than being smooth like normal, the engine was pulsing/surging.
lately i have had the feeling of loss of power and fuel economy but thought it was just me getting used to the ute still as its only just clicked 11k on the odo,
called the dealer and they will look at it tomo....do you guys think its the same issue, and i assume its covered by warranty?

[gregned]

I have the same issue occasionally.
Doing 50 accelerate to 60 and the damn thing pulses at about once every half second ie 0.5 Hz
Will normaly do it on cold mornings/ nights when engine is warm.

[longsville]

Dropped it off at the dealer in Hobart today......
1stly got awesome service, did early bird drop off got a call half way trhough the day to say it is the SCV, but they wont get the part till Friday. Straight away they organised a loan car for me.
So it does appear its the same issue

[Sky Miner]

Just had my MN checked over (30000klm service) with the same simptoms' manifold nipple was blocked and the boost senson is faulty allso thay ordered new manifolds (intake+outlet) to be replaced when thay get em in stock
I dont know what thay did but its going a "HELL" of a lot better allready should get up a booggie when all is replaced
EXCELENT!!

[longsville]

So got off the phone to the dealer this arvo, the ute has been in since last tuesday with this SCV issues...thats all they have said it needs.
And he tells me they will have it another week as they have no parts in stock....anyone know of any delays.
Not really to much of a bother because they have given me a loan car, but a Kia Cerato is nowhere near as good....or powerful as my triton!!

[Sky Miner]

So got off the phone to the dealer this arvo, the ute has been in since last tuesday with this SCV issues...thats all they have said it needs.
And he tells me they will have it another week as they have no parts in stock....anyone know of any delays.
Not really to much of a bother because they have given me a loan car, but a Kia Cerato is nowhere near as good....or powerful as my triton!!

My stealer told me it'll be 2 weeks before my parts arrive so just keep driving around tll thay get here no probs cant wait like waiting for a new car to arrive been driving like a real slug for ages.(not me the car )

[pbouf]

Got a 2010 GLX-R mn manual & Just clicked over 60000 ks & started surging again today. Already been to the dealer twice with the same issue, starting to get a little annoyed but will ask about the SCV issue. Also just started having probems with gearbox selectors at last service & dealer informed me that the gearbox has to be pulled out & sent to repairer for at least a week. Have I got a lemon or is there similar stories out there? Also, which fuel company do you reckon has the best diesel, caltex or shell?

Cheers, Bouf

[Cowboy Dave]

Also, which fuel company do you reckon has the best diesel, caltex or shell?

Neither. BP is better than both IMHO. If I had to I'd go with Caltex after that but it's much of a muchness.

[fraz91]

I'd be curious to see what people are getting from the Mobil Diesels. Any 7/11 servo that has replaced a Mobil servo gets Mobil fuels, and as of early next year (could be wrong) all 7/11 servos are getting the Mobil fuels. I know Mobil Oils are regarded as some of the best you can buy, but what about their fuels?

[Kegsy]

Mobil / 7-11 is all that I use in mine. Never misses a beat.

I don't rate vortex at all and BP isn't around my area, and where I work all fuel is a rip off.