Hissing EGR valve and related TPS / fuel pump question

[tonydca]

I finally traced down an annoying hissing noise on startup with my L400.

It only occurred when the beast was starting from dead cold (and disappeared after a few seconds), and intermittently under load. The latter accompanied a bit of a lack-of-power at speed and a recent fuel economy drop from 12.5L/100k to around 15L/100k.

I had previously cleaned out the over-pressure poppet valve on the rear of my intake manifold (see earlier post) and my boost gauge is showing 11 psi, so not the culprit.

So I removed my EGR valve, and lo and behold it was nicely coked up and failing to seal properly. Exhaust gas was leaking by the valve and around the shaft of the valve itself (the outside of the valve shaft was getting black from sooty blow-by).

So one fabricated blanking plate on the intake manifold later, and although the hiss remains, she pulls stronger, and is less rattly on cold startup.

One other thing I discovered on my research on the UK website is that the ECU uses the throttle position sensor (TPS) readback to determine when to close the EGR valve. Having earlier adjusted my TPS to make the tranny shift earlier and smoother, I find out that this same operation causes the EGR to close at much higher RPMs, robbing power at moderate engine speed.

So if anyone out there has recently adjusted their TPS down to around 0.8V like I did, the UK site seems to recommend blanking off the EGR valve too.

Finally, the last thing to fiddle with for me is the fuel pump. I understand that the delivery setting is a relatively simple mechanical system with two adjustment screws; one to set max fuel flow, and the other to adjust the offset based on turbo outlet pressure.

I have no idea how to properly calibrate these settings. Having found out that my TPS adjustment has messed up my EGR, now I want to make sure that my fuel pump is set correctly.

Anybody calibrated one of these before with sage advice to give? Thanks.

[FalcoColumbarius]

Have you looked at the fuel system download in L400 Delica Downloads? It has a pretty extensive view of the L400 fuel system. It's under Delica Canada Technical/FAQ's & Downloads/L400 Delica Downloads.
Hope this helps.

Falco.

[jessef]

Funny I'm in the same boat.

My initial readout on the TPS was 2.8v . I was being robbed gobs of power on acceleration and horrible shifting patterns.

After driving quite a few L400's, I have a good feel of what feels right and what doesn't.

I tossed in a boost gauge and I'm running at max 10-11psi.
Pyro temps are low and oil pressure is good. (put those gauges in too).

I brought the TPS voltage down to .75 and it drives like a dream now.

I haven't blanked off this EGR and will do so very soon.

Once I get that done, I'll increase the boost psi and mess around with the fuel screws as well and report back.

Going to try and get the exhaust done first so it can all breath better.

[tonydca]

Thx Falco, lots of info on how to set the timing, but nothing on how to adjust the delivery quantity (I assume it just adjusts the delivery pressure).

I'll dig around the UK site a bit more...

[tonydca]

I do not know how I managed to survive before Google (the Dark Ages).

Found this on a Pajero blog site:

http://4x4pajero.spaces.live.com/blog/c ... !225.entry

*******************************************

Injector pump adjustment (copy from PeterMiller):

Tools Required: 10mm socket / bar /ratchet 13mm combi spanner Stubby screwdriver
Step 1: Remove Inter-cooler
Step 2: Locate Pump Adjust
At the back of the pump where the diesel line goes in, there's a banjo.
Just underneath this there's a 13mm nut. (This may be covered by a metal cap with a nipple looking end - take it off if it is. Mine wasn't covered - obviously not put on after the SVA). Uncrack this nut - there's an adjusting screw located inside this nut.
Step 3: Adjust Pump, NOTE: Based on my symptoms of no smoke, barely reaches 80mph, dies going uphill, poor mpg - I was advised to turn the adjuster screw in on and 1/4 of a flat inwards. A flat is not a whole turn but merely a single edge of the nut - ie. a hex nut, one turn is one side of the nut. Nip up the 13mm nut.
Step 4: Put intercooler on
Step 5: ** IMPORTANT** Reset spring in governor
Start up
Tick over for a few secs
Slowly rev to 2.8k / 3000rpm gradual build up & let off real slow. Then floor it! Over 3000rpm & let off a quick – ignore engine twang this is just the governor reseting - mine didn't make any noise.

*********************************************

Mine makes very little smoke if any, and assuming she can hit 120+ on the highway, I suppose I'll just call it good and leave well enough alone.

[tonydca]

More comprehensive tuning post on UK Pajero site:

http://www.pocuk.com/forums/viewtopic.p ... sc&start=0

Might be a bit Over The Top, but interesting reference material.

[jessef]

More comprehensive tuning post on UK Pajero site:

http://www.pocuk.com/forums/viewtopic.p ... sc&start=0

Might be a bit Over The Top, but interesting reference material.

Good stuff. That's what I've been going on.