LD28 timing

[wrwsailing]

I have a 1985 Albin 27 boat with a Nissan LD28 engine, adapted for marine use. The timing belt was recently changed--I am satisfied that the mechanic set the timing the way the manual shows. However, the engine will not start without a spray of ether--not good--it surges, and performs poorly. I am beginning to believe that my engine is set up different from the way the manual shows or something else is wrong. It was running fine before the timing belt was changed. Does anyone have any suggestions of what I can try or how to reset the timing? Any help will be most appreciated.

[TheDieseliminator]

Hi, and welcome to the site. The LD28 actually doesn't use a timing belt but rather a belt to run the injection pump. If that were to break you just stop the pump from turning to deliver fuel to the engine. The engine uses a timing chain, which you can see if you take the valve cover off. It's an OHC design and you may need to disassemble it to figure out if the sprocket is located in sync with your chain (markings). If you can't happen to fix the timing correctly at the top of the engine you'll have to take the front cover off to get it back to factory spec. Someone should post info/directions out of the correct year factory shop manual. Good luck!

Salvy

[asavage]

Welcome to our Sandbox!

The IP belt is easily misinstalled. In particular, there are TWO sets of marks on the IP sprocket, shown at the bottom-left of this page from an LD manual. However, if the wrong mark is used, not only is ether required to start it, but it will run very poorly with the extremely advanced injection timing. I know this because I've done it. If left in that condition, it will eventually ruin the engine -- and in a matter of minutes or at most hours. The timing will be way off.

Also, unless you buy the IP belt from the dealer (which has the 20-tooth interval paint-marked on the belt's back), you do have to count pretty accurately to get it on right.

See also the FAQ, IP Belt entry for some more info.

Ether to start is bad!

If it runs well after starting, have you put a voltmeter or test lamp on the glow plug bus bar and ascertained that the GP system is working? Sure, the GP system is unrelated to changing the IP belt, but that doesn't mean that something couldn't have been knocked loose during the maintenance.

Lastly, setting the injection timing on the LD28 requires special tools -- tools that for the most part do not exist. In a marine application, it may be possible to use the VW adapter for the back of the IP's test port to perform the IP timing, but in the Maxima the only recourse is to fabricate an adapter -- nobody sells the factory tool, not even Nissan.

So, your assumption that your mechanic set the injection timing right may be incorrect. If he was smart, he didn't touch the IP's adjustment at all -- toothed belts do not stretch appreciably (unlike timing chains); merely replacing the belt is all that's necessary. Without the correct IP dial indicator adapter, you are far more likely to make the IP timing worse by moving the IP and changing the timing, than getting the timing closer to factory spec. Read the FAQ, IP Belt entry for details.