Patrol GU 2.8 TDI

Submitted: Wednesday, Jun 04, 2003 at 09:32
ThreadID: 5274 Views:4390 Replies:1 FollowUps:1
This Thread has been Archived
Hi all, This may apply to any turbo diesel. My Patrol was suffering from jerky accelleration under heavy load (what's required to get moving actually) I thought this was a fuel starvation problem or bugs in fuel, changed filter and filled right up thinking it would go away with use.
I discovered it was running on full boost due to a signal line (air) to waste gate actuator being open to atmosphere, fuel is cut by solenoid valve at pressure switch setting to protect engine from overload. The original signal line had been cut to fit tee for boost controller (part of Motsom power chip installation) The short section of new hose from tee had softened and become detached at tee, no clips fitted.
Also waste gate linkage was seized but freed up with spanner and CRC, tested actuator with 12v compressor(keeping pressure below 1.0 bar) Seems ok now and trying to set up boost control to just below safety pressure switch setting. I have fitted a tempory boost gauge and it reads 0.8 bar (11.7 psi)
Does anyone know what the correct max should be ?? I think the pressure switch is the one on front of intercooler but I can not read what's on it.
Regards, Bob W
Back Expand Un-Read 0 Moderator

Reply By: Hugh - Thursday, Jun 05, 2003 at 00:24

Thursday, Jun 05, 2003 at 00:24
Hi Bob,

I have a 2.8 TDI in a GU as well. I would be interested in your feedback regarding the power upgrade and whether the improvement met your expectations.

As for the bypass controller: according to GQ factory supplement for the RD28T engine (very similar), Nissan quote stroke/ pressure at 0.38 mm (0.0150")/ 85.3-90.6 kPa. They also caution not to apply more than 98 kPa pressure to the diagphram.

I'll have a look at my engine to see if I can gain any info from the pressure switch. If you wanted to know what pressure trips the switch, then you could apply pressure to the switch and increase and monitor electrical output via multimeter.

I hope this helps,

AnswerID: 21889

Follow Up By: Bob W - Thursday, Jun 05, 2003 at 10:03

Thursday, Jun 05, 2003 at 10:03
Thanks Hugh -- I feel the power upgrade chip is worthwhile, the 2.8 needs something to get it moving !
The blurb says you can gain 30% but the place I had mine installed had no working dyno so I do not know what I get but it is substantial. Cost is prohibitive at $1300 but may be less now as there are more brands available ?
Still trying to tune my boost pressure, moved tee for gauge to outlet from intercooler supply to waste gate as gauge was to close to boost control bleed and giving wrong reading, now getting 1.05 bar (15.4 psi) and the waste gate is operating as the pointer on gauge fluctuates at max pressure. The fuel cut soleniod is not operating at this pressure but I may still drop it back a tad as I do not want to find out the expensive way that it is overloading engine.
I should see what max boost can be obtained by disconnecting waste gate whilst I have temporary gauge set up !!! 15.4 psi seems very high ??
Bob W
FollowupID: 14319

Sponsored Links