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GU ZD30 Di hesitation & starting issues


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Hi all,

So a few weeks back I bought my first GU, engine has had a full rebuild with receipts & about 50,000kms driven since rebuild was done. EGR blocked, 3" echaust fitted and dyno sheets showing boost up to be 18psi I believe on stock boost solenoid.

Now, at first all I had was the usual limp mode from the EGR being blocked as well as the check engine light from the EGR, the boost would spike up to 20psi and be in a limp mode until you let off the accelerator and back on again, it was annoying for long trips on the highway but still driveable. So my plan was to get a HPD manual boost controller fitted to fix the limp mode issues. But I noticed one day that the boost was running slightly lower then when I first bought her, she would only go to around 14psi which I thought nothing of until the boost controller was going to be fitted.

Then after filling up with diesel, around 10 minutes into my drive home I felt a weird jerk/judder in the car almost like all fuel just cut out for s split second then back to normal. Watching the boost gauge, the boost also dropped out too as you would expect so I thought it was a boost problem. It slowly got worse over time becoming a lot more frequent it does it just above 2,000rpm and around 10-13psi of boost, started in 5th gear, now in 4th and 3rd as well but only around those rpms and boost levels. It also took a bit longer to start in the mornings letting out a puff of white smoke I think, not blue.

I took it to a diesel specialist about an hour away as I'm in regional Victoria and they called me the next day and said they scanned the car and got a code for the camshaft position sensor and the injection pump, so they said the issue is definitely the injection pump which they quoted me $5000 to do the job. I don't have that kind of $$ at the moment haha but after doing a bit of research on forums I've read up on MAF voltage causing the same kind of symptoms as well as a blocked fuel filter/air in the lines. I did clean the MAF with MAF cleaner before and it made no difference so while it was at the diesel specialist, I just told them to change the fuel filter for now and see if that makes a difference. So $150 later just for that, the guy called me saying that the car was running alright and didn't notice it playing up again, he also said they took the plugs off the injection pump and sprayed them with contact cleaner and all the codes disappeared aswell?

I was very happy with that as you'd imagine. So I picked it up the next day and it was another hour to drive back home in which it was bound to do the same things if it wasn't fixed. On the way home it drove fine, only jolted/juddered about 4 times max (it would easily do it over 30 times before) so I thought replacing the fuel filter must have done something. I've had it back about a week almost and just been driving it to and from work, 5 mins there and 5 back. It's gone back to doing the same thing as before except this morning it wouldn't start after about 2 minutes of trying, it would crank but not start. I don't have a code reader that can read it. I did call Nissan and spoke to a mechanic for about 5 minutes and he said there's 3 common things to check first before replacing the pump, can't remember what they were off the top of my head but I do remember him saying something about the spill valve?

I'm just wondering if anyone has had the same problems and what they did or their solutions before I spend $5000 on the injection pump and it may not even fix the problem.

Thanks, Ben

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Firstly I'd would make sure that harness to injection pump is OK. There is a short piece going from engine interface bracket to pump and it is not uncommon for the wires to wear out inside the conduit there. That dumbo mechanic cleaned the plugs so he disturbed the harness temporarily fixing it. Any codes?

Anyway you need to specify which model is yours, year or series perhaps.

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If I check to see the wiring harness is okay will I also disturb it? Is it easily accessible?

I have these ECU codes;

1003 - EGR Volume Control Valve

0406 - INT / AIR Volume (Excessively High Signal From MAF)

0407 - Crankshaft Position Sensor

0705 - Pump Control Module

 

It is a 2001 Patrol GU with ZD30 DDti engine.

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Are any of these codes active?

You really need to see what ECU is doing and its sensors.

ECU Talk software with its Nissan Consult II adapter cable can read the sensors in real time so you could use it to pinpoint cases.

Pump harness is reasonably accessible however I'd not call it easy. 

Regards

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14 minutes ago, Rumcajs said:

Are any of these codes active?

You really need to see what ECU is doing and its sensors.

ECU Talk software with its Nissan Consult II adapter cable can read the sensors in real time so you could use it to pinpoint cases.

Pump harness is reasonably accessible however I'd not call it easy. 

Regards

Yes they are all active as of now, I've checked my MAF voltage output on the pins via another forum and my readings are lower than what they should be so MAF sensor is definitely an issue.

The crank sensor also has a split right near the connector that's exposing the actual wire so that's probably why I have the crankshaft code.

I have ECUtalk software but I can't get it to work with my Bluetooth OBD2 adapter for the life of me!

If I fiddle with the pump harness could that affect it in any way? Are they very sensitive?

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20 minutes ago, bistratoaie said:

Yes they are all active as of now, I've checked my MAF voltage output on the pins via another forum and my readings are lower than what they should be so MAF sensor is definitely an issue.

The crank sensor also has a split right near the connector that's exposing the actual wire so that's probably why I have the crankshaft code.

I have ECUtalk software but I can't get it to work with my Bluetooth OBD2 adapter for the life of me!

If I fiddle with the pump harness could that affect it in any way? Are they very sensitive?

ECU Talk will never work with OBD2 adapter sorry incompatible protocols! You will need to use Consult II interface/adapter those cables are available from its website.

I'd be lost without it.

Code 0406 :

An excessively high voltage from the mass air flow sensor is
sent to ECM when engine is running.
If there is NOT 0102 code present it is likely that MAF sensor is not faulty and actually measuring high air flow.

Possible causes are:

However above doesn't take in to account that you have:

Blocked EGR, fitted 3" exhaust and left stock controller in the place. What that does is causing it to overboost and triggering safety "limp" mode in certain RPM range.

This is well known to all of us who mod this POS.

if you get 18 psi out of yours and that's why you are getting that code!

 

Code 1003

probably cause it is either disconnected or other way electrically disabled, normally we leave it connected electrically and block the port with metal shim so ECU is none the wiser as it doesn't actually measure the EGR flow like on much later vehicles it just guesses so it is dumb and to our advantage.

 

Code 0407

If you see bare wires then yes not good, I will attach some info on checking these codes, bare with me

Edited by Rumcajs
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Ah so which cables would I need exactly to work with my vehicle? Like I said, it's got the OBD2 adapter under the steering wheel in the foot well but I know it runs on Nissan's consult protocol.

Yeah I have all those mods done to mine so I'm not surprised about the MAF sensor fault.

The EGR is blocked off so that's not an issue for me, that shouldn't affect driving.

I can see bare wire on that crankshaft sensor connector so looks like 2 new sensors so far for me!

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This doesn't compute cause 2001 Patrol with ZD30 never had OBD2 plug. It had grey Nissan Consult II. Nissan started with white colored OBD socket from 2004 series 4

however it is still only wired up as Consult II interface. Not compliant with OBD2 protocol. That happened with the arrival of common rail ZD30 in 2007 onwards.

Ecu Talk cables

I have the OBD2 socket in mine and cable for it ==> Y61 ODB2

ECUTalk_OBD2_cable.thumb.jpg.75d3476a2aefec0eb0fa3e2530c88367.jpg

 

 

So,

If you have those mods you must take control of the turbo charger away from the ECM or must limit max boost bellow 15 psi and bellow 11 psi at or bellow 2000RPM.

Thats why Dawes valve or Tilix valve is used to limit max boost, to control spool up rate needle valve is used ......

It is still not enough so basically keep the accelerator pedal light bellow 2000 RPM and if/when it limps learn to quickly release it and re-apply....

I suggest you search on these forum thread about NADS.

0406_DTC_1.jpg

0407_DTC_1.jpg

0407_DTC_2.jpg

0705_DTC_1.jpg

EGR_1003_code_checks.jpg

Edited by Rumcajs
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Mine has the same plug as the OBD2 socket image you sent, would I need an ECU talk cable with that OBD2 plug for it to work with the software?

Thanks for all that mate! I will be doing some tests tomorrow in-between work and I will let you know what I find!

Edited by bistratoaie
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Yes you will need that cable for it to work with ECU Talk software.

In regards to injection pump:

Search online for testing VP44 injection pump (and its Zexel clone). the issue is that the pump has its own ECU and has its own diagnostic codes which are not visible to main Engine ECU (ECM) so to make diagnosis you will need Bosch scanner for such pumps (only Bosch fuel injection diesel specialist have them) and only then I'd say needs the new pump.

If you are feeling adventurous you can create your own K line protocol OBD2 custom interface but research it thoroughly. You will also need to create the custom injection plug (PSG5)  and OBD2 plug to make that harness and then another serial USB to OBD2 adapter to connect to it! (Not ECU Talk cable)

See this diagram 4db5cf2s-960.jpg.aa4b38d459ee6a4e9edb5b542d72e484.jpg

 

In the zip file attached is what is claimed as VP44 diagnostic software. I came across it but never used or tested it. So thread carefully. Also confirm that wiring on yours is the same as example provided.

 

Note on the pump code 0705 :

You will get it when there is air in fuel, suspected points of entry can be priming button on the filter housing, incorrectly fitted fuel filter, or dodgy fuel lines.

I'd confirm the grounding point on the inlet manifold as they can be suss, I'd also make sure the main ground cable from battery to chassis and engine block is OK. Indeed Patrols are notorious for bad grounding so if in doubt run your own extra ground cables from chassis to body and battery to body/chassis/engine.

IP harness to check/follow location

Injection_pump_harness_example.jpg.8b95941f624c110ffffdd6cbf3324a21.jpg

 

ECM_to_IP_diagram_early.jpg

whole.zip

Edited by Rumcajs
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23 minutes ago, Rumcajs said:

Yes you will need that cable for it to work with ECU Talk software.

In regards to injection pump:

Search online for testing VP44 injection pump (and its Zexel clone). the issue is that the pump has its own ECU and has its own diagnostic codes which are not visible to main Engine ECU (ECM) so to make diagnosis you will need Bosch scanner for such pumps (only Bosch fuel injection diesel specialist have them) and only then I'd say needs the new pump.

If you are feeling adventurous you can create your own K line protocol OBD2 custom interface but research it thoroughly. You will also need the custom plug IP plug or T-off existing harness to make up the rest. (Not recommended) CAUTION! You have been warned!

See this diagram 4db5cf2s-960.jpg.aa4b38d459ee6a4e9edb5b542d72e484.jpg

 

In the zip file attached is what is claimed as VP44 diagnostic software. I came across it but never used or tested it. So thread carefully. Also confirm that wiring on yours is the same as example provided.

 

Note on the pump code 0705 :

You will get it when there is air in fuel, suspected points of entry can be priming button on the filter housing, incorrectly fitted fuel filter, or dodgy fuel lines.

I'd confirm the grounding point on the inlet manifold as they can be suss, I'd also make sure the main ground cable from battery to chassis and engine block is OK. Indeed Patrols are notorious for bad grounding so if in doubt run your own extra ground cables from chassis to body and battery to body/chassis/engine.

 

ECM_to_IP_diagram_early.jpg

whole.zip 242.36 kB · 0 downloads

Thankyou very much this all a VERY BIG HELP in diagnosing my issues. If you have a read in the other forum where I posted my issues, it shows some MAF readings I got and a couple of pictures I think have to do with my issue, and the 0705 - air in the fuel, just confirmed my suspicions with the fuel line from the fuel filter to the Injector pump.

https://www.patrol4x4.com/threads/gu-zd30-di-hesitation-starting-issues.411931/

Edited by bistratoaie
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7 minutes ago, bistratoaie said:

@Rumcajs how did you find out exactly what code 0705 was? Is there a list of injection pump codes anywhere?

That code is general trouble from pump ECM and it has a few reasons/conditions.

Quote: 
Injection pump control unit has an on board diagnostic system,
which detects malfunctions related to sensors or actuators built-into
electronic control fuel injection pump. These malfunction informa-
tion are transferred through the line (circuit) from injection pump
control unit to ECM.

Now from past experiences I know that code is set e.g. when there is air in fuel as it affects pumps ability to do fuel metering....so it guesses.

Its called "garbage in causes garbage out" in other words wrong input means wrong outputs.

Regards
 

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4 minutes ago, Rumcajs said:

That code is general trouble from pump ECM and it has a few reasons/conditions.

Quote: 
Injection pump control unit has an on board diagnostic system,
which detects malfunctions related to sensors or actuators built-into
electronic control fuel injection pump. These malfunction informa-
tion are transferred through the line (circuit) from injection pump
control unit to ECM.

Now from past experiences I know that code is set e.g. when there is air in fuel as it affects pumps ability to do fuel metering....so it guesses.

Its called "garbage in causes garbage out" in other words wrong input means wrong outputs.

Regards
 

No worries, is there anywhere online I can look at to read the injection pump codes?

Ah that's good news because I have a small and slight leak from the fuel filter hose directly to the injector pump so that could definitely cause that issue? It doesn't sound like the injection pump is faulty then?

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On 10/12/2020 at 9:39 PM, Rumcajs said:

It would be possible source of your trouble. Fix and test. It is cheaper then throwing expensive injection pump at it.

Consider adding external fuel lift pump but remember to modify injector overflow/spill line.

Regards

 

I have since reset my ECU because it was not starting with the codes stored. I also cleaned all the earths on the manifold and the battery posts and terminals, and added a body to chassis earth underneath near the cross member. I also added an earth wire going from the MAF wiring to the body to help it have a good and proper ground as I was getting 0.04v on the Black wire when diagnosing.

I have also replaced the fuel outlet hose and hose clamps from the fuel filter going to the IP as it was split and leaking a bit of diesel (maybe why I was getting code 0705?). Primed, and took 2 pumps to prime hard with no visual leaking or no noise of air leaking!

I received my new MAF sensor and installed today, car started nicely after installing, haven't done any test driving yet as I know I need to replace the crank sensor which I have but am waiting on a feeler gauge to gap it correctly.

Do you know what the correct gap is for the crank sensor? Is there a specific way to remove/install it?

Thanks.

Edited by bistratoaie
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Ah sorry mate, forgot you had posted them earlier 😅 I'm just waiting on a feeler gauge at the moment so I can correctly gap the sensor.

Do you recommend taking anything off the front of the engine to access it? Or is it pretty accessible without removing engine parts?

Thanks

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@Rumcajs checked codes before replacing crankshaft sensor and I had 0407 - crankshaft sensor & 0703 - pump comm line

Replaced crankshaft sensor to the same gap as the original sensor (0.8mm), and checked codes again, this time the crankshaft 0407 code had gone but 0703 was still there, do you know what might be causing this code?

Thanks

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So just an update:

I replaced the crank sensor with the new one and ran the wiring up the same way out of the way of the clutch fan and pulleys so as to not fray the wiring like the old one. I also found a pinched vacuum line under the intercooler (not sure which one it was), but I cut off at the pinched area and rerouted it to sit nicely with no more kinks.

I had the 0407 crankshaft code, 1003 egr code and also had a 0703 pump comm line code before commencing the work.

Before and after replacing the sensor, I could not get it to start and the battery was dying so I once again took the terminals off to reset the ECU and charge the battery overnight.

 

Connected it all back up this morning and went to start her and she fired right up after a little white smoke. She was idling really good for 5 or so minutes before I turned her off and started her again to make sure she would fire up nicely and sure again, she fired right up with no issues at all. Took her for a 15min drive in all gears up to 100km/h and safe to say so far, no issues at all! There was no hesitation or spluttering like before so hopefully I'm onto something here! The check engine light did come on and I suspected it was the EGR again and when I got back from my drive, I checked the codes and it was the EGR 1003 code only, so far so good!! Now to get rid of that damn limp mode around the 80-100km/h mark

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@Rumcajs

So once again, left it to sit overnight thinking I'd take it to work in the morning. I was ready to leave at 5am it was around 7°c, I waited for the glow plug light to go off and turned the key off and back to ignition a couple times but the car just cranked over and over for a few seconds without firing up until the battery got tired again.

 

Only code I had was 0703 pump comm line.

 

After work, I disconnected the 9pin plug on the back of the IP as well as from the harness and also the glow plug harness connector and gave them all a really good direct spray with contact cleaner and there was a little bit of dust and dirt in them but I cleaned them all right out!

 

Had battery disconnected while I was doing all the work and when I finally finished (took me about an hour all up), I connected it all back up and went to start her and just cranked a few times and battery got tired again. Checked codes and still had 0703 pump comm line? I'm confused now, not sure what to do from here? 🙄 Got battery on charge again, will try to start it after the arvo shift.

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I think it is harness to the injection pump...

You've fiddled in there and now disturbed something for good.

0703 DTC is about ECM to IP comm which means voltage range is out due to either shorted wires or broken wires....

See bellow how to check:

DTC0703.thumb.jpeg.1194a0d4b951d4db3ebd91a9ca806d5a.jpeg

DTC0703_p2.thumb.jpeg.764f697372ae71851344a038ee3855bb.jpeg

Wiring_Diagram_ECM_to_IP.thumb.jpeg.48f1b5b053a90844a1907463cda2103b.jpeg

 

 

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@Rumcajs I followed the DTC diagnosing procedure for the 0703 pump comm code and everything checked out to be okay, I did take the IP connector off and out again and gave it one more good spray all over and checked the wires again and all was good. I made sure to install it correctly and out of the way as well as zip tie it to a bracket to reduce any movement while driving.

Alsosprayed the MAF connector and EGR connector and connected that back up since it was unplugged. Although some wires are no good and have been cut/frayed so I need a wiring diagram for the EGR connector!

I also removed the ECU connector and sprayed thoroughly in there and the ECU terminals as well and did it up nice and tight to see the orange (although I did it too tight and the 10mm bolt and plastic bit snapped off somewhere so I need a new plastic casing part which covers all the wires and screws in if you know where I can get one?) 😫

I primed the pump 2 times in which it went hard and it started up first go with only a couple seconds of cranking, I think the pump comm line must be good now 😁 now to test in a couple hours when I have work!

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Have not had the 0703 code again, only 1003 which is for the EGR. Although it does take a while/few times to crank to get it started overnight, primer goes fully hard in about 3-4 pumps so I'm thinking there may be some air in the system? Do you know the best & easiest way to bleed air out of the system @Rumcajs? Would it be loosen an Injector a bit and crank then check primer till it gets fully hard on say 1 push?

 

Thanks!

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