GU III Limp Mode ZD30??? , HELP

[Retired and loving it]

I raised a post a while ago about diagnostics (15TH Jan ) but this one has got me beaten, as mentioned before this was the second motor failing from over-boost (cracked & holed pistons) towing 2.5 ton caravan.
Block Overhauled, new pistons, rings, bearings, refurbished injection pump, new MAF sensor, everything elso OK spent about $5K so far. But she won't rev above 2000-rpm, put air con on & revs halve, runs smooth at idle, the exhaust gas only climbs to a fraction above 200deg c at any time, -no fuel..hence turbo running & has limited boosting, Exhaust & cat converter all ok as I have run disconnected. Blocked & unblocked EGR sys and made no difference, Leak tested intercooler, pipes & hoses all ok, Timing spot on, with glow plugs or injectors out motor turns over very easy with spanner @ front pulley.
Have checked all fuel lines, purged out back to tank, new fuel filter, all hoses tight & no leaks.
I am stumped,
Is there a limp mode that stays locked @ low fuel/revs until Mr Nissan can enter some sort of a secret overide code????

[Bigrig]

Patch! Tony! One of the mechanical stars!!!

Hang tight mate, someone will have an idea ...

[teleman]

Well i was gonna say that i had the same problem. Well, similar problem. I had no boost at all and was running very sluggish and slow. My mechanic ended up replacing both the MAF and Boost sensor. Car runs a dream. Just a little thing to try... turn the car on, idle for 3mins, then turn off and step outside. Lock and unlock the car 3 times in quick succession. (I'm assuming you have keyless entry)
If this doesnt work then ask Mr nissan to rest the whole car.
The only difference between your symptoms and mine were the revs. mine would go past 2000 but very very slowly.

[Yendor]

Hi Don,

I was wondering how you were going with this.

To the best of my knowledge there is no magic code/reset.

Did you get the injectors tested when the pump was done?

Were you able to get all the sensor inputs to the ECU tested?.

From what you have said, it does sound like it is starving for fuel.

Have you spoken to the mob that supplied you the refurbished pump?

[Retired and loving it]

Hi Don,

I was wondering how you were going with this.

To the best of my knowledge there is no magic code/reset.

Did you get the injectors tested when the pump was done?

Were you able to get all the sensor inputs to the ECU tested?.

From what you have said, it does sound like it is starving for fuel.

Have you spoken to the mob that supplied you the refurbished pump?

Please see my update, at bottom of post (all fixed)
thanks
Don

[Steve cooper]

Hi mate,
It's very difficult to try and diagnose something like this over the Internet, however something strikes me as strange.....

U say the revs drop (halve) when u turn the AC on, is this at idle or with ur foot on the throttle?
Have u tried to check for fault codes (manually), there is a write up on here somewhere on how to do it?

The ac speed increase request is computer controlled, however the speed increase will only work at idle. If its not functioning then u perhaps may have a computer fault, that could be very hard to pin down without swaping another computer in.

If u are unable to retrieve fault codes manually then I think your only option will be to take it to a mechanic with a diagnostic tool.

Was this problem present before the injector pump was overhauled?

Might also be worth checking the injector pump connector to make sure it is connected home properly, and also check to make sure that all the pins are clean, making good contact and haven't backed out of the connector.

The injector pump operation on these is controlled by computer mounted on the injector pump, that in turn is controlled via a low-speed can-bus signal from the engine computer. If u can confirm that your Maf sensor and map/boost sensor are operating correctly then the problem will likely be around the pump, pump computer, ECM and related wiring.

Please keep in mind that this is a total shot in the dark, but it may help u to fix it, or at least understand what is happening.

I will be interested to see how u go.

Steve

[joelogozzo]

Hi had the same problem with mine, found out it was code 0407 , which ia a crank sensor, picked one up at a wrecker for $80 esay to replace and the thinks been running great since.

[Retired and loving it]

FIXED: HOORAY at LAST
Block overhauled, new pistons, rings , bearings, new MF sensor, reconditioned Fuel Injection Pump, Stumbling block was lack of Revs above 2000RPM, Replaced Injectors now runs like a dream. Re-set Turbo adjustment vane set screw to ensure maximum boost at any time in all conditions to 15PSI (used Large Independant Test Pressure Gauge)
A lot of thanks go to Garry at Sydney Diesel Centre (02 96817700) who helped track down the problem and supplying New Nissan Injectors at a very Cheap Price. yehaar..... :-)

[Retired and loving it]

Patch! Tony! One of the mechanical stars!!!

Hang tight mate, someone will have an idea ...

Please see my update, at bottom of post
thanks
Don

[Retired and loving it]

Hi mate,
It's very difficult to try and diagnose something like this over the Internet, however something strikes me as strange.....

U say the revs drop (halve) when u turn the AC on, is this at idle or with ur foot on the throttle?
Have u tried to check for fault codes (manually), there is a write up on here somewhere on how to do it?

The ac speed increase request is computer controlled, however the speed increase will only work at idle. If its not functioning then u perhaps may have a computer fault, that could be very hard to pin down without swaping another computer in.

If u are unable to retrieve fault codes manually then I think your only option will be to take it to a mechanic with a diagnostic tool.

Was this problem present before the injector pump was overhauled?

Might also be worth checking the injector pump connector to make sure it is connected home properly, and also check to make sure that all the pins are clean, making good contact and haven't backed out of the connector.

The injector pump operation on these is controlled by computer mounted on the injector pump, that in turn is controlled via a low-speed can-bus signal from the engine computer. If u can confirm that your Maf sensor and map/boost sensor are operating correctly then the problem will likely be around the pump, pump computer, ECM and related wiring.

Please keep in mind that this is a total shot in the dark, but it may help u to fix it, or at least understand what is happening.

I will be interested to see how u go.

Steve

Please see my update, at bottom of post
thanks
Don