Patrol 4x4 - Nissan Patrol Forum banner

1 - 10 of 10 Posts

·
Safari Hoarder
nissan
Joined
·
4,731 Posts
Discussion Starter #1
Subject: 1994 LWB Y60 Safari High Roof (or loof ha ha) with the TD42T (not Ti), auto of course, party roof, rear beer cooler and third row seating.

Condition: 125 000 kms, no rust. Very good condition.

Problem: I wanted to adjust the timing and up the cracking pressures. The engine was down on power and economy a bit.

Discovery: Injectors removed to find they are the same as the non turbo 0050 B and 113 nozzles. Injectors tested and nozzles worn out; some thin streams that changed position with every stroke, some sticking on 3-4 of the injectors and 1 injector was sticking worse than the others.

Procedure: Injectors overhauled (by me) and cracking pressures set to 1800 psi with 121 nozzles. Injectors installed and engine has a distinct diesel sound again.

The IP on this Safari is a little different than the non turbo Safaris. I had asked a few members about what to expect for static timing (cam disc lift) but I was a little surprised to find 0.43mm. Timing reset to 0.53mm

Test runs to go.....

Any feedback on the timing appreciated.
 

·
Registered
Joined
·
20 Posts
opening pressures etc

Hi twinotter , 105007-1130 nozzles are the same for turbo/non turbo engines , usually the 1210's are used in the td27-t 4cly engines but set to the same opening pressures.
1800psi/180bar is getting into the realm of direct injection , that combined with the extra advance you've given the pump will be the cause of your "distinct diesel sound" , i'd be inclined to lower the opening pressures to around 140-150 bar and leave the pump timing as is and see what result you get , i've experimented with timing and opening pressures and have found that a moderate increase in the opening preesures with about 0.10mm above standard pump timing spec to be the most beneficial.See how you go.
 

·
Registered
Joined
·
20 Posts
Timing

Hi twinotter , forgot to mention in my reply that the later td42-t engines 98 on, pump timing we set to 0.48mm so the 0.43 you got sounds right .
 

·
Safari Hoarder
nissan
Joined
·
4,731 Posts
Discussion Starter #4
Thanks BIGE. After installation of the nozzles I ran the engine and the "distinct diesel sound" was there right away. I did not notice any difference after changing the timing. I`ll run it for a bit unless there is some danger to the engine....
 

·
Safari Hoarder
nissan
Joined
·
4,731 Posts
Discussion Starter #5
Let's discuss the higher cracking pressure a bit. New nozzles (or is it new injectors) are supposed to be set at 1640 psi, so 1800 is 140 psi over that. I am thinking the "distinct diesel sound" that has resulted from the higher pressure is the better atomization and metering of fuel and thus a faster and more complete burn....????

Whether a faster burn is better in the TD42T I don't know, it's an indirect.....

The "distinct diesel sound" lessens as rpm is raised. I will have it on the road/highway today.
 

·
Registered
Joined
·
20 Posts
opening pressures

Hi twinotter, zexel specs say 100 bar/1450psi for 1210 nozzles which are designated to the td27-t 4cly engine, by raising the opening pressure you are in effect retarding the timing as the injector is opening later.It does however make it atomise better, but by adjusting the pump timing up you are compensating for the differance in injection opening. I have my pump set at 0.81 and injectors at 130bar/1885psi., but my pump is modified to pump more fuel and I run higher boost than standard.
 

·
Registered
Joined
·
20 Posts
opening pressures

Must appologise for the earlier thread about the pressures , 1800psi is 124bar not 180.
 

·
Safari Hoarder
nissan
Joined
·
4,731 Posts
Discussion Starter #8
Hi BIGE, what engine and pump are you running at 0.81? Would it be similar to my '94 Safari?

After running around yesterday I can say the performance is up, less pedal on the highway and good low end. Certainly not the performance change I experienced from timing a NA to 0.81.

So from 0.43 to 0.53 I am thinking of going up another 0.1-0.2. Without going on the dino (not common around here) I would think too far would cause more diesel knock and performance loss.
 

·
Registered
Joined
·
20 Posts
Pump and engine

Engine is a factory 94 turbocharged engine that I rebuilt , with a hybrid turbo that I built up starting with a garrett td03 core assy.Pump is modified with a bigger plunger and set up to pump about 40cc more fuel than a factory spec pump.It also has a big front mounted intercooler and I have a pyrometer to keep an eye on egt's.Fortunately we have a 4wd chassis dyno in our workshop so I've been able to experiment with various settings etc and see the "real time results".
 
1 - 10 of 10 Posts
Top