Outer Limits 4x4 Board

While working on a mate's 4BD1 county with a rebuilt engine I noticed the timing was set on 5° BTDC (mark on pump and spring-advance housing lined up).

The timing is suposed to be about 10-13° BTDC. By moving the pump 1.5mm away from the mark I managed to advance the timing to about 6°, but I doubt I could get it much further. I suspect the people who built the motor fitted the pump a few teeth out...

Anyone know the maximum amount of advance you can get without pulling the pump and rotating the gear and refitting???

I dredged up this post while I was searching for something else.

But anyway, check this page out, it has a list of injection timings and emissions categories.
http://library.motoralldata.com/techRef ... u_isde.htm

You'll notice that in california the timing is set to 6 deg, the rest of the US got 14 deg.
I suspect that the timing was retarded in california to reduce peak cylinder temps and reduce NOx formation.
Which would indicate the the engine runs at it's most efficient at the 14 deg setting.

There was an excellent thread up on 4x4wire by a guy called "Crossbones" about diesel injection timing. He mentions using the glowplugs as thermocouples (type B) to determine the best timing based in mimimum cylinder head temperatures.
I expect an EGT probe will give similar results, optimal timing = lowest exhaust temps at steady load.

It's not something I've experimented with yet. But one day.

*edit*
I got the 14 and 6 around the wrong way
*/edit*

G'day Ben,
Have a look at this site, might have the info you're after....http://www.4btswaps.com/forum/forumdisp ... rune=&f=16

The engine Ben is talking about was rebuilt here in Australia then shipped to a mate of mine in Canada. It was in a 5 door County. I drove it from Vancouver to Panama and back, with Ben and his wife flying in to meet me in Guatemala. We got back to Canada OK then blew the head gasket. The standard of the rebuild was questionable to say the least and the engine only lasted 30,000 kms.

Ben had to fly home so I finished the work. I was able to get a lot of movement by just slackening the nuts/bolts holding the pump and adjusted the timing without pulling the pump.

1103.9TD wrote:G'day Ben,
Have a look at this site, might have the info you're after....http://www.4btswaps.com/forum/forumdisp ... rune=&f=16

The internet is way too small, that's me too.