TD42 engine missfire

[sudso]

It only started doing it in the last few months and it only does it now and again under acceleration, more so when the engine isn't fully warmed up.

It's a GQ, TD42 with a DTS (MTQ) water cooled turbo.
The injector pump was reco'd about 3 years ago.

Any idea's?

cheers, sudso

[Peter @ Aawen4x4]

Happens around 2500-3000 revs, and it seems to be a miss or two then picks up almost straight away? The revs are usually the same, but for some its at 2500rpm and for others its at 3200 rpm.

It is most likely not sufficient transfer pressure in the fuel pump! An easy fix from a Diesel injector pump tuner, but they do hafta take the end off the pump to adjust it, so it takes a while, maybe 1.5 hours. We found it on 9 out of 10 of the TD42's we had on the Snowy, but the fix was so simple, and it really is only because of the 'compromise' initial tuning set-up on the pumps.

I'd guess that when they did the reco on the pump, they set everything back to Nissan spec's, and it's been there ever since. If you aren't looking for it, it would be very easy to miss, until you start doing things like looking for the last Nm or Kw that you can get, coupled with playing with wheel sizes etc. If the vehicle was bog standard, and you didn't know it did it, you'dprobly miss it too.

Can't really think of anything else that it's likely to be, 'cos diesels can't 'MISS-FIRE' as such, and how would you lose compression only sometimes and only on one cylinder? Wouldn't have thought that the rings would be that mobile in the guides that they could spin around and release the compression intermittently. It's GOTTA be a fuel hiccough, and the transfer pressure thingy I KNOW does just that, so I'd be punting for your problem being that.

I take my Patrols over to Cooma Diesel (in Canberra) and it is well worth the trip! Get the diesel injectors and pumps checked over every 100,000 or so, and it usually works out about once a year or year & a bit. It has made significant improvements in the performance and fuel usage and the gains are backed by dyno runs before and after. If you want details, gimme a yell and I'll look them up!

[sudso]

Happens around 2500-3000 revs, and it seems to be a miss or two then picks up almost straight away? Yep!

It is most likely not sufficient transfer pressure in the fuel pump! An easy fix from a Diesel injector pump tuner, but they do hafta take the end off the pump to adjust it, so it takes a while, maybe 1.5 hours. We found it on 9 out of 10 of the TD42's we had on the Snowy, but the fix was so simple, and it really is only because of the 'compromise' initial tuning set-up on the pumps.

I'd guess that when they did the reco on the pump, they set everything back to Nissan spec's, and it's been there ever since. If you aren't looking for it, it would be very easy to miss, until you start doing things like looking for the last Nm or Kw that you can get, coupled with playing with wheel sizes etc. If the vehicle was bog standard, and you didn't know it did it, you'dprobly miss it too. Not sure what they did with the tuning as the previous owner had it done at Adelaide Injector Service at Regency Pk.

Can't really think of anything else that it's likely to be, 'cos diesels can't 'MISS-FIRE' as such, and how would you lose compression only sometimes and only on one cylinder? Wouldn't have thought that the rings would be that mobile in the guides that they could spin around and release the compression intermittently. It's GOTTA be a fuel hiccough, and the transfer pressure thingy I KNOW does just that, so I'd be punting for your problem being that. Yeah I know they dont "missfire" but its the same feeling as when a petrol does it.

I take my Patrols over to Cooma Diesel (in Canberra) and it is well worth the trip! Get the diesel injectors and pumps checked over every 100,000 or so, and it usually works out about once a year or year & a bit. It has made significant improvements in the performance and fuel usage and the gains are backed by dyno runs before and after. If you want details, gimme a yell and I'll look them up!Gee I dont know about going all the way to Canberra just to get the pump looked at. I havent any reason to go there at this stage. I might hit up the local Nissan mech and see what he can do.

And thanks for the info Peter! Knew I could count on ya!;)

[Peter @ Aawen4x4]

Gee I dont know about going all the way to Canberra just to get the pump looked at. I havent any reason to go there at this stage. I might hit up the local Nissan mech and see what he can do.

And thanks for the info Peter! Knew I could count on ya!;)

I had a pump reco'd over here, but was not real happy with it, took it to a few of the local big name people and they all said it is absolutely spot on the Nissan Specs and we can't make it any better than that! Eventually bit the bullet and took it to Canberra and came home with a bunch more horses and a heap of extra Nm's and no cost in terms of fuel usage! It was pre turbo days, and the only time I've felt that sort of improvement since is when I've had a turbo fitted!! You'll get improvments by getting it done over here, you'll get the best improvements by taking it to Cooma Diesel (or Berrima Diesel!)

It IS worth the time and effort, and you won't need to do it too often, most would only ever need to do it once on their vehicles, they don't keep them much longer than 100,000km!!

[sudso]

I wonder if AIS at Regency tuned it to factory specs and not to suit the turbo, which was already fitted.
And why has it only started to do it:confused:

[Peter @ Aawen4x4]

Funny that you should write exactly what you did write (and when you wrote it too)!! The thought had crossed my mind and we were talking about the likelihood while you were posting! Spoooky, hey!

It may well be that it hasn't just started, but that it was doing it all along and while everything else was in top nick, it wasn't really noticeable. Now that everything has had a bit of a time to go off the boil, and the rest of the settings are just beginning to go off too, it's becoming more and more obvious! As other settings slide away from spec over time, and they do, then the hesitation will probably become worse and worse, until eventually it'll probly be undriveable!

I found one like that in the snow one year, couldn't get the revs up and over the hesitation, it stalled out every time!! The vehicle was only driveable at low revs, as soon as he tried for more speed/power/revs it hesitated .......... pause, two, three; and then died! The guy was not very impressed, and even less impressed when it took just a short while to fix it and make it Sooo much better!! He thought he had a NEW turbo, or at least an intercooler!

The guy at Murray Bridge Diesel is very good at what he does, no Dyno tho, and nowhere near the rep of Cooma Diesel or Berrima Diesel.

[sudso]

Thanks Peter I'll have a chat to him.

[sudso]

The guy at Murray Bridge Diesel is very good at what he does, no Dyno tho, and nowhere near the rep of Cooma Diesel or Berrima Diesel.A mechanic mate down here reckons they do have a 4wd dyno now:confused: and he recommended them as well without knowing they already were.
Might take the GQ next trip to Adelaide and drop in there me thinks.

[Peter @ Aawen4x4]

Well that's a good thing then! They had been talking about getting the dyno, but last time I was there it was still in the "deciding to do it phase!!" They are good, and they are the only people in SA that I've ever heard recommended by Cooma Diesel; they actually let the Murray Bridge guys do locally some of their less critical hands on work with Injector pumps, and they don't have someone in every State, they only let that out to people who are good enough!

So if you are going anywhere here, that'd hafta be the top of the list!

[oondy]

hate to point out/ask the obvious, but have you changed your fuel filter recently?

when mine starts to hesitate under acceleration, thats when I know it's time to change the filter - problem solvered.

cheers

OONDY

[FERAL ERROL]

here here, oondy

[sudso]

hate to point out/ask the obvious, but have you changed your fuel filter recently?

when mine starts to hesitate under acceleration, thats when I know it's time to change the filter - problem solvered.

cheers

OONDYHow often should it be changed? every 5K, 10K, 20?
Is it a DIY job with a diesel? I havent changed it since I bought it and I've done about 8500 kays since.
I didnt ask the previous owner when he had it changed so maybe thats the problem and I run a bit of Chemtech diesel conditioner with each tank fill too. Maybe it's loosened up crap in the tank.
How much are the filters? Nissan or Bosch better?

cheers, dave

[Peter @ Aawen4x4]

Normally you'd only change the fuel filter every 40,000km, with inspections of the water trap at every 10,000 km interval. You will find that the OE Fuel Filters are quite expensive, and for a small initial outlay, you can get an adaptor that will allow you to replace the OE Filter Element with a CAV style or even a Ryco Filter Elelment that cost significantly less. I generally recommend that if you are going remote, change the OE element for ne of the aforementioned cheaper versions and carry a few. Then change them with every oil filter change, or whenever you feel the slightest doubt about the quality of the fuel or the functioning of the filter!

With the OE Elements, when you need to drain the water trap, simply disconnect the wiring from the bottom of the filter, place a container or cloth underneath to catch the liquid draining, and loosen the drain valve until the stuff starts draining, often takes a fair few turns (5-10ish!) Try not to take it right off tho'! When all the discoloured fuel or water etc has drained, tighten it up and reconnect the wiring.

When you want to remove/replace the OE Element, do everything up to the end of 'etc had drained' then simply use a filter removal tool to spin the filter element off, swap the water trap fitting across to the new element if applicable (often not!) then fit the new element after lubricating the sealing ring with clean diesel. Tighten the element 2/3 of a turn beyond where the sealing ring first touches the sealing surface of the filter head. Fit the wiring into place, then bleed the fuel system.

But seriously look at the aftermarket replacement filter heads. They will filter to a cleaner level without impeding the fuel flow, they are significantly cheaper than the OE Elements, and they make you far less concerned about changing the elements at the slightest indication of there being any issue with the fuel cleanliness!

But I don't think the symptoms you are experiencing now are necessarily as a result of the filter being blocked. They are too much like the hesitation that almost every TD42 diesel either has or will get at some stage of its life.

[sudso]

Thanks Peter. Think I'll print out those instructions. Looks like a bit to remember! :)
The filter unit on mine is a Bosch unit, made in Korea.

Another Q while ur here, the bleeder nipple next to the filter, thats to bleed the master cylinder yes?

BTW I started making these up. Thought I'd better start something until I get my own equipment ABN etc.
http://www.4wdmonthly.com.au/forum/f17/gq-rear-worklight-posts-strong-35932/

[oondy]

when we were at Ngarkat the other aussie day weekend Peter, when going up a certain hill, can't remember which one, I gave it a bit and sure enough got to about 3000RPM and it started coughing and spluttering and wouldn't rev any higher.

when I revved it in nuetral, no probs all the way to the redline but with a bit of load on it.....got to any where from 28-2500RPM and just wouldn't go any higher.

as soon as I got home from that trip that day I changed the filter - man it was a different car to drive......so now every time it starts to nose dive in power I replace the filter and it's back to the normal NA TD42 power levels.....if you could call it "power".

cheers

OONDY

[Peter @ Aawen4x4]

If it's the bleeder nipple that I think it is, then it is probly the bleeder that is on the clutch hydraulic line. The Nissan Clutch has two bleed positions, that one, which is usually used for vacuum bleeding of the clutch hydraulics, and the one down on the slave cylinder, which on these vehicles is generally only used when they need to gravity bleed the clutch hydraulics. But for you and me, without the more expensive gear that the workshops usually run, the bottom one is probly the only one that is going to work for what we do. You can use the top one up near the fuel filter, but you'd STILL hafta bleed the rest of the system down to the slave cylinder, so it might add all of a couple of minutes to the taks just to go direct to the slave cylinder!

Brake lines often also have a mid-line bleed point too, but again, you've still gotta go to the end of the line, the wheels, unless you've got a vacuum bleeder, so they won't help too much without one of them!

You got clutch or brake problems too?

[Peter @ Aawen4x4]

when we were at Ngarkat the other aussie day weekend Peter, when going up a certain hill, can't remember which one, I gave it a bit and sure enough got to about 3000RPM and it started coughing and spluttering and wouldn't rev any higher.

when I revved it in nuetral, no probs all the way to the redline but with a bit of load on it.....got to any where from 28-2500RPM and just wouldn't go any higher.

as soon as I got home from that trip that day I changed the filter - man it was a different car to drive......so now every time it starts to nose dive in power I replace the filter and it's back to the normal NA TD42 power levels.....if you could call it "power".

cheers

OONDY

Yeah, I know what you mean Oondy, but there is also quite frequently a less intrusive 'hesitation' that you will find around that same sort of rev range, maybe a little higher. And it generally won't stop the theing from going past it, until the fuel pump is well on its way out anyhow. So while changing the filter is a good idea, except where you hafta pay $80 a shot, although I don't think anyone uses the OE bits anymore, even some Nissan Dealers don't stock them, they run cheaper replacements!

But once you've changed the filter, if that hesitation is still there, and you probly won't notice it ALL the time, just every now and them it'll hiccough just there before pulling on, then it is likely to be that Transfer Pressure issue. And the only way to remove it totally is to get the pump tweaked, cos they've gotta open the end of the pump to do it, and fit in dial gauges etc to determine exactly what's what and where it should be. Once done, very unlikely to ever need doing again, but if it hasn't been done, there is about a 90% chance that you'll run into it eventually!

When I first encountered the hesitation in a vejhicle here in SA after leaving the Snowy (BTW, Cooma Diesel looked after and fixed all their Patrols, that's where I got the 9 out of 10 vehicles from!) I couldn't find anyone in here Adelaide who managed to fix it despite a few trying(although wether it is a case of 'couldn't' or 'wouldn't' is another matter!) but once I got the vehicles over there, Cooma Diesels only took about 20 mins and I havent had the hesitation ever since on either of those two vehicles, between them now with over 500,000km of hesitation free driving!

The Red Patrol tho', it has recently started exhibiting the hesitation too, and nothing I have done in the way of changing filters, cleaning fuel systems, upping fuel flow, etc has gotten rid of it. When I checked with Cooma Diesels to see if they had touched that area of the injector pump when they fitted the turbo, they hadn't done that 'cos when they did the turbo it hadn't shown the problem! It has now, so I might hafta see what I can do about getting someone to look at it! I believe these guys in Murray Bridge have since been trained up by the right people to manage to do it properly, so they might be a stop on my itinerary soon too!

[sudso]

You got clutch or brake problems too?No but a complete change of fluid would'nt hurt it.
Clutch does fully grab when the pedal is less than an inch from the floor but its been like that since I've owned it.
All I've done is adjusted the m/c pushrod but it made no difference.

[Peter @ Aawen4x4]

Do you still have those gearbox noises you had a while back? Or you have them but are waiting to replace the gearbox with a second hand unit?

[MUDRATGQ]

Gday guys ive got the 4.2 petrol carby model an i am haveing the same problem got any ideas

[nayto]

How often should it be changed? every 5K, 10K, 20? Im with oondy on this one also, i change fuel filters every 10, maybe overkill but gives a bit of reassurance for me. On the nissans they also have a tiny thimble filter inside the fuel pump. Its located under the banjo fitting on the inlet hose to the pump IIRC.Ive had the eaxct same problem before with a TD42, and thats all it was. You'll need to remove the line, and use tweezers or something to remove it. Also some already have had them removed. Hope this helps. Ive got the part number for a new one if needed...

[sudso]

Do you still have those gearbox noises you had a while back? Or you have them but are waiting to replace the gearbox with a second hand unit?
Some are still there but the really noisy gritty one is gone. Maybe the offending part is all ground up to metal flake now lol.
I'm dropping the oil this weekend to have a look.
Not sure which way to go yet, gamble on a second hand box or get this one reco'd locally.

[nayto]

so whats the go mate......what'd u end up finding with the fuel dramas you were having???

[sudso]

so whats the go mate......what'd u end up finding with the fuel dramas you were having???No I havent looked at the filter yet.
Everytime I go outside I see something else that needs doing around the house lol.
I'm hardly driving it at the moment anyway but I'll post up the details when its sorted for sure.

cheers