Patrol 4x4 - Nissan Patrol Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Hello,

I need help!!

My 98 GU Patrol has been struggling with a hard start issue for 18 months. I've had the injector pump rebuilt twice and it has been triple checked by 3 different pump houses and I’m still having hard start problems. It takes about 30 seconds to start from cold (18 deg C ambient temp) and 15 seconds for a warm start, and no problem with a hot start.

This is a list of parts replaced over the last 18 months/20,000 Klm:

-Air filter x 1
-Fuel Filter x 2
-Oil/Oil Filter x 4
-Mass Air Flow Sensor x 1
-New # 1 injector (with sensor) and 2-6 injectors rebuilt x 2
-6 Glow Plugs
-Timing Belt + Tensioners
-Crank Shaft Timing Sprocket

Countless hours and diagnostic checks have been done by 2 different mechanics including a Nissan Dealership, even to the extent where an injector pump and computer were borrowed from another car and tested. The result was the donor injector pump worked on my car but the computer did not (may be coded??), unfortunately my pump was not checked on the donor car. So my injector pump was sent off and rebuilt again. When it came back the car was running fine and then all of a sudden mid test drive it lost power and started blowing smoke, so back to the workshop, it appeared that one of the rebuilt injectors malfunctioned hence the second rebuild.

If you can get the car started, it runs really well and hardly any smoke...The mechanic is looking at the possibility of a faulty computer?? Faulty wiring loom?? Crank angle sensor??

Can anyone suggest anything, are there other control modules on the injector pump which are not checked during a 'bench test' and rebuild.

I feel it has something to do with timing, because everything that would need to be rebuilt has been and by 3 different companies which would make it hard to believe that something has been over looked.

Your advice will be greatly appreciated.

Thanks
 

·
Registered
Joined
·
757 Posts
these sorts of problems can really test you love for your vehicle and i hope you find the problem sooner rather than later.
Without knowing what your machanic has tested i might be repeating some things here but i wonder if its worth testing the glow plug relay system and timer as although the plugs are fine if the relays or timer are faulty it may be causing you grief. Just a thought on that if the glow plug system is not working correctly i found with mine anyway that it will start a lot louder than normal as it struggles to burn the cold fuel. It will quiten down after 10 or so seconds.
Has your machanic pluged his computer in to your vehicle to check to see if any faults re listed.
The last idea i would have was early this year i had a lot of trouble starting mine after the injector pump and injectors were overhauled (when cold) and i would have to crank it over for a while. mine ended being low compression in the last 3 cylinders due to a crack in the head (also had a burnt valve).
Maybe look at getting a comprssion test just to be sure.

I wish you all the best in your trouble shooting.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #3 ·
Thanks for your input,
The compression is good, all 6 cylinders are around 420 Psi.
The glow plugs are working properly however we have by-passed them and hooked 12VDC straight to the plugs for 10-15 seconds and then tried starting with no change.
The strange thing is that when you try starting the engine there is unburnt fuel smoke coming out of the exhaust while its turning over, then it coughs and starts but will stall if you don't rest your foot ever so slightly on the accelerator. So it seems that its getting fuel and it has compression what else is there?(hypothetical question) Its as though a switch or solenoid has stuck stopping a critical step from taking place in the starting sequence.

I do wonder about the valves, if the timing is out perhaps valves are partially open during the starting sequence, is that possible?
 

·
Registered
nissan patrol y61 2.8
Joined
·
48 Posts
is the injection pump timed correctly?

is fuel draining back to the tank, try a non return valve on the fuel hose.
 

·
Registered
Joined
·
757 Posts
Here are a couple of other ideas (you might have already tried them) have you checked the fuel cut off soliond on the injectgr pump? maybe remove the plunger and see if it starts without the plunger in.
The other idea is you said you had to have you foot resting on the pedel when starting. it might be worthwhile checking the throttle sensor. Seeing there is no throttle cable the sensor might be playing up a little.

The above post is also a good point has the injector pump timing been checked lately?
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #6 ·
An update on the problems I've been having.

The mechanic took the car to a diesel place in Sydney. They checked the pump and it was fine, then they moved on to the timing where they replaced the belt and the tensioner pully now the hard hot start is gone and the car runs fine. However I am still stuck with a cold start issue but, if I switch the glow plugs on twice it will start straight away, still a bit rough but significantly better. The glow plugs are all new. Is there anything else in the starting sequence I'm missing?
Would replacing the glow relay or wiring help?
 
1 - 7 of 7 Posts
Top