Terrano R50 TD27 bad idle stalls- intermittant

[rangimotors]

Just after a bit of input from the experts. I am working on an R50 terrano with the TD27 intercooled turbo engine. Mechanically it go's well. When driving it there is plenty of power and everything runs and sounds normal. However every now and then when stopping at the lights or letting it idle it has a poor uneven idle and sometimes stalls and will take a few times to get started again. Does anyone have any thoughts?

I am starting to think it is something like a TPS and crank agnle sensor or map/maf sensor but not knowing anything about nissans I don't even know if it has these.

Any thougts or advice would be good. I get an error code (flashing check engine light) when it stalls but it goes away when i turn key right off and then back on. Not sure if this is normal for a stall or if the fault is whats causing my stall. I will have a go at a few things myself and wait for some advice before taking it in to have the faults scanned.

Thanks.

[tweake]

get code read would be the first thing. write down the code and don't rely on what the manual says is wrong.

one of the common things is air being sucked in.
also those injection pumps are know to wear out fairly quick.

[rangimotors]

Yes i did have thoughts of a possible split in a line somewhere, possibly intrcooler or a vacuum line or something. When it happens its a bit like a car with a stuffed airflow meter or unpluged, it will go if you put ya foot up it and won't idle. If the manual is wrong for fault codes do you know where i would track down a correct list of them? No point in paying for the fault testing if the results mean nothing.

I have come across others vechicles with good manuals that give an ohm reading for the various sensors at TDC etc, does anyone have anything like that for an r50? Google is not playing the game. I'm sure I can do a bit or trial and error and unplug a sensor a a time to try and replicate the fault but then again what ever is causing the fault is intermittant so hard to track down.

I also read that these had a bit of a problem with poor earthing so I'll try a new strap or clean up the old ones and cross my fingers for a cheap easy fix.

[Landy Rover]

Common faults Ive come across is air leak between air flow sensor and turbo, Accelerator pot ( on pedal) and faulty injection pumps. Would pay to scan the ECU as any codes will be stored in memory. OBD2 diagnostics works on these vehicles.

[rangimotors]

Thanks mate, any further info on pinning down which one it could be. Not to keen on paying 800 for a pump if i dont need it. Obviously i can check the pipes for leaks or splits etc but anything further?

[Landy Rover]

Check the air intake pipe from air flow sensor for splits, might need to take it off to check it properly, they are about $120 new.
I would seriously get the ECU scanned before replacing anything else except that air pipe if needed, otherwise its just a guessing game and a huge amount of time, plus there could be other faults stored as well which is usually the case. If you havnt got a scanner most auto sparkies will do it for you for a small fee,, well worth it.

[DieselBoy]

Have you replaced the diesel filter's??

[rangimotors]

No not yet, I'll have a hunt around and see if I can find where they are. I would of thought that would restrict the flow during driving and make it run like a dog but idle ok. Thanks for the tip I'll try anything it's always a process of elimination with faults like this.

[tweake]

actually i meant suck air into the fuel. typically poor filter seal, primer pump seal and sometimes hose connections.
sucks a stream of air in which is can handle but slow down and the air forms a bubble and starves the motor for a short while.

its not the codes the manual gets wrong its the conclusion to what the cause. eg air being sucked in can show up as defective injection pump.

[rangimotors]

ok I understand, I have had a chat to a specialist who seems to think it will be the electronic governer on the fuel pump, hopefully its something else i'd rather not fork out for one of those if i can avoid it.

[Landy Rover]

actually i meant suck air into the fuel. typically poor filter seal, primer pump seal and sometimes hose connections.
sucks a stream of air in which is can handle but slow down and the air forms a bubble and starves the motor for a short while.

its not the codes the manual gets wrong its the conclusion to what the cause. eg air being sucked in can show up as defective injection pump.

Yes, fuel filter housings are prone to leaking air, but from my experience it shows up as hard starting when left overnight or whatever.
In Rangimotors case, unfortunately it does sound like a pump issue, as it is electronically controled and DO give trouble at higher Ks 200+
When the ECU logs a code, whatever it is, is out of range but not nessesarily the exact fault, but at least you know what circuit to start looking at.

[Navara_Man]

check what it idles like from cold to warm and see if what injector pump it has in it. Have you checked the idle when in nuetral or when the clutch is in? as this can sometimes be the case as well i have found or if it has an auto choke on it ?

i have a td27 non-turbo and had the same problem kind off, you would come to a stop and if would idle fine then when i went to go it would just lose power and die!

I had a play around and asked around and found out some td27 have electronic injector pumps and some have mechanical, mine was electrical and was at the end of its time! Apparently the mechanical ones you cant beat, i got a second hand one from an old terrano for $100.

[rangimotors]

yes this one has the electronic one in it which i suspect is my problem.
It is also auto, it is the same right from cold to running temp , the idle is very uneven it basically drops to 4-500 and then jumps to 7-800 constantly. It won't stall if i pop the auto into neutral when stopped but left in drive with foot on drive sometimes it will stall.
Probably pull out the pump and take it into diesel specialists down parkhouse road and see what they think.

[Navara_Man]

have you thought of the injectors as well???

i had the same problem in a isuzu wizard of mine, although the injectors were faulty from new due to a call back. but the same thing happend it was also an auto and the check engine light would come on and then it would stall.

[tweake]

i've heard of the torque converter causing it too.

[rangimotors]

interesting, one of 100 dfferent causes. Start at one end and work through it until i narrow it down i guess

[rangimotors]

Common faults Ive come across is air leak between air flow sensor and turbo, Accelerator pot ( on pedal) and faulty injection pumps. Would pay to scan the ECU as any codes will be stored in memory. OBD2 diagnostics works on these vehicles.

I'm thinking that it may have somethig to do with the accelerator pot, as today a has a new failt (i assume its still linked) Started uo fine first pop but had a rough idle, put it into drive (foot on brake) and it was still the same, did not stall but i let my foot off the brake and put it onto the accelerator and the truck stayed on idle, put my foot to the boards on the gas pedal and still nothing happened truck was just on idle and rolling slowly along the road. Started messing around pumping the gas pedal etc and suddenly it came to life and worked as normal. Certainly seemed electronic so i'm thinking the POT is stuffed and its not getting the correct signal or the electronic govner is stuffed and not letting the pump feed gas when its required.
Might be time to go see an auto sparky..

[phaedrus]

Hey Rangimotors - just wondering if you eventually got this sorted? I have an R50 with essentially the same problem but I'm fairly sure it's not the accelerator pot and am trying to follow through a fault-finding process which is increasingly looking like the pump but I'm not convinced (also it looks expensive!).

Thanks for any info you may be able to pass on...

[rangimotors]

sure did it was the injector pump, needed a re build.

[Crash bandicoot]

Common faults Ive come across is air leak between air flow sensor and turbo, Accelerator pot ( on pedal) and faulty injection pumps. Would pay to scan the ECU as any codes will be stored in memory. OBD2 diagnostics works on these vehicles.

yep

[phaedrus]

Thanks for that Rangimotors - I don't suppose you know just what in the pump was faulty?

I do suspect that's what is wrong with mine but I'm still working on narrowing it down - incidentally Crash and Landy the protocol and 14p connector on this ('96) R50 is Nissan Consul, not OBD2. That's ok 'cos I've made the necessary interface and have checked the stored fault codes etc but it's worth bearing in mind, later R50's may well have the OBD connector with Consul protocol.

Being the person I am, and given what I do, it's highly possible I'll have a go at the pump myself (hence my interest in what was at fault in RM's machine) so if anyone has any idea of common problems there I'd be interested. I will be approaching it from a first principles perspective but anything that gives one a headsup has got to be useful!

For those that are interested I've been able to reduce the severity of the problem when it's cold by disconnecting the ECU water temp sender unit. This sets the apparent temp to a constant 80deg (but doesn't affect the dash gauge) and I suspect reduces the amount of fuel being injected. The problem doesn't go away but it's marginally less annoying.

If I have time in the weekend I'll have a closer look at the control circuitry to the VE pump but I need to make a suitable timing gauge adapter as well (to fit my dial gauge) as I suspect the timing is a little out so that may chew into the time I have available. I expect one should be able to time it with the data from the crankshaft position sensor and the #1 injector lift sensor but I'm not certain what the measured value should be at a specific RPM.

Anyway, back to the problem, I want to see what info the ECU sends the pump directly when the fault occurs so I'll need to get an oscilloscope running in the cab. If the surging is commanded (ie. the ECU is generating the signal that causes the inj pump to operate that way) then it may be possible to further reduce the severity by introducing some damping into the control circuitry - it wouldn't be a fix per se but it might give a little longer before the problem becomes so severe the vehicle can't be used.

If it's not commanded then the fault is generated and controlled within the pump and so there's less one can easily do I imagine. I may end up modifying the vehicle to fit a mechanical pump (at least for the interim since I have one) while I have a good look at what's going on inside this electronic unit....

P.

[rangimotors]

yea i had thoughts of rebuilding it myself as even though i was happy to pull the pump out myslef and drop it off to the rebuilders the quote was still mostly labour. I beleive it was just a standard rebuild kit for the electronic pump. Didn't look to hard but the guys (right or wrong) convinced me that the hardest/most important part was the pressure testing etc after it was complete and setting it up correctly. Since they do them every day i decided i'd give it a miss however i would be keen as to have a spare one to pull apart and have a good play with to work out exactly what is involved. I have since sold the truck so not such a worry anymore.

If you have any luck or give it a go and chuck some info and pic's up on here, its always nice to have a bit of tech reference when you look at doing it your self.

cheers and good luck.

[TD power]

its ur pump govener mate sorry if its hunting and stalling mate but drives ok i can prety much say its the pump

[Landy Rover]

Thanks for that Rangimotors - I don't suppose you know just what in the pump was faulty?

I do suspect that's what is wrong with mine but I'm still working on narrowing it down - incidentally Crash and Landy the protocol and 14p connector on this ('96) R50 is Nissan Consul, not OBD2. That's ok 'cos I've made the necessary interface and have checked the stored fault codes etc but it's worth bearing in mind, later R50's may well have the OBD connector with Consul protocol.

Being the person I am, and given what I do, it's highly possible I'll have a go at the pump myself (hence my interest in what was at fault in RM's machine) so if anyone has any idea of common problems there I'd be interested. I will be approaching it from a first principles perspective but anything that gives one a headsup has got to be useful!

For those that are interested I've been able to reduce the severity of the problem when it's cold by disconnecting the ECU water temp sender unit. This sets the apparent temp to a constant 80deg (but doesn't affect the dash gauge) and I suspect reduces the amount of fuel being injected. The problem doesn't go away but it's marginally less annoying.

If I have time in the weekend I'll have a closer look at the control circuitry to the VE pump but I need to make a suitable timing gauge adapter as well (to fit my dial gauge) as I suspect the timing is a little out so that may chew into the time I have available. I expect one should be able to time it with the data from the crankshaft position sensor and the #1 injector lift sensor but I'm not certain what the measured value should be at a specific RPM.

Anyway, back to the problem, I want to see what info the ECU sends the pump directly when the fault occurs so I'll need to get an oscilloscope running in the cab. If the surging is commanded (ie. the ECU is generating the signal that causes the inj pump to operate that way) then it may be possible to further reduce the severity by introducing some damping into the control circuitry - it wouldn't be a fix per se but it might give a little longer before the problem becomes so severe the vehicle can't be used.

If it's not commanded then the fault is generated and controlled within the pump and so there's less one can easily do I imagine. I may end up modifying the vehicle to fit a mechanical pump (at least for the interim since I have one) while I have a good look at what's going on inside this electronic unit....

P.

I have a Snap on scan tool and used the OBD2 function to extract codes off an R50. Worked for me

[phaedrus]

Rangimotors - I will see what a rebuild kit costs here, not much in some other countries from what I can tell! I'm like you in that I'd rather have a spare to be doing this with but all my other Nissans are mechanical pumps unfortunately...

TD - thanks for that, makes sense. I'll have a further look at it this w/end if I have time (too busy with earthquakes!), I'll post what I come up with.

Landy - I wonder what year that was, presumably a later one? I've got an OBD interface here too but it won't fit this '96 Terrano.

Ciao, P.

[Landy Rover]

Was a 96 R50, the scanner didnt have any presets for Nissan diesels so tried using OBD2 and got results. Its not a bad scanner but find you have to work outside the square when using it on some vehicles.

[phaedrus]

For those that are interested I installed the mechanical pump this weekend.

The conversion was reasonably straightforward, use the throttle cable from a D21, modify the existing pedal assy, fit a boost compensator fitting into the manifold (remove the EGR valve and thread the resulting hole). Biggest pain is removing the pump, they don't make it easy. Need to run a 12v switched feed to the stop valve (I took it from another feed under the bonnect), otherwise it just works

There are some downsides - the tacho doesn't work and the MIL is flashing like mad. There is another fail condition that's occuring with the 4WD light lit but it still drives happily and there's no apparent change issues with the auto.

If anyone has the ec data for the R50 with TD27 - and/or the pump manual - I'd be keen to see it. I have the Mistral (R20) manual (yes I've got one of those too) but the wiring connector is different. It'd be good to get the tacho working and perhaos fool a few of the other lines into thinking everything is connected, for that I need a bit of info. Also I'd be good to have a bit of data on the electronic pump I took out 'cos I'd like to strip it down...

When I have a chance I'll do a little write-up with photo's etc.

P.

[DjWesty]

For those that are interested I installed the mechanical pump this weekend.

The conversion was reasonably straightforward, use the throttle cable from a D21, modify the existing pedal assy, fit a boost compensator fitting into the manifold (remove the EGR valve and thread the resulting hole). Biggest pain is removing the pump, they don't make it easy. Need to run a 12v switched feed to the stop valve (I took it from another feed under the bonnect), otherwise it just works

There are some downsides - the tacho doesn't work and the MIL is flashing like mad. There is another fail condition that's occuring with the 4WD light lit but it still drives happily and there's no apparent change issues with the auto.

If anyone has the ec data for the R50 with TD27 - and/or the pump manual - I'd be keen to see it. I have the Mistral (R20) manual (yes I've got one of those too) but the wiring connector is different. It'd be good to get the tacho working and perhaos fool a few of the other lines into thinking everything is connected, for that I need a bit of info. Also I'd be good to have a bit of data on the electronic pump I took out 'cos I'd like to strip it down...

When I have a chance I'll do a little write-up with photo's etc.

P.

Hey mate any chance you did end up doing a write up for this?? If so id love to see it. Im in the situation now where i think i need to replace my pump and would way rather modify to suit a mechanical pump.
Few questions.. Do you NEED the boost compensation fitting? Ive never seen one of these but im guessing a blanking plate over the egr flange with a threaded hole in it will work??

Also Did you get your tacho working? would a tacho from a terrano with a mechanical pump work possibly?
and you said you 'MIL' was flashing like crazy. What is mil? obviously a light, but what light haha

Cheers
Dj

[ChurchurDan]

Holy thread dredge batman.
Ask crash he is still here and has done it

[Crash bandicoot]

I'll keep this brief

Yes your pump is had it. non serviceable. (not the actual pump but everything that controls the flow of fuel through it)

Yes it is cheaper to install the mechanical injector pump from the prefacelift TD27-t

No you don't need a boost compensator but you will sacrifice the broad torque curve for a narrow one if you use a N/A pump.

You will need to remove the vacuum pump from below the injector pump to
get to one of the 3 12mm bolts holding the pump to the timing gear housing.

Dont move the 14mm adjuster further back just unbolt the whole mount from the block and then swap it to the mechanical pump when you install it
(saves having to set the timing again.)

You will need to unbolt your accelerator pedal and remove the reinforcing plate from behind it.(it's blocking the hole for the accelerator cable)
Use one from a D21 Ute.(cable that is)

then crimp your cable to the exisiting one that goes from the pedal to the potentometer (you will see what I mean when you take it out)
Why you ask( 1 if you have an automatic trans you will still need the potentometer to control the TCU/transmission and 2 if you buy a mechanical pump from a forklift or manual vehicle the pump won't have a potentometer on it ).... if you have a manual box just bif the electrical's in the bin.



Leaving your ecu in place will still allow your tachometer to work. (even though it is now redundant.) as it converts the negative signal into a positive( or grab the tacho from a earlier R20 that still employs the negative pulse and just change the face over and install it in your instrument cluster. .

Anything else PM me