KA24E timing chain install instructions - Page 3

isb360 · Sep 9th, 2008, 01:56 PM

BoltBrain,

What a missive you wrote! I will offer my thoughts for what they're worth.

1) I am not familiar with the RWD layout of the truck engine, but it sounds like the distributor is in a different place than on the FWD Stanza. On the Stanzas, the timing chain is on the right side (pass) and the distributor is on the left (driver's) side, driven off of the camshaft.
The timing marks should have lined up perfectly, not "almost" perfectly. Your cam timing is now either advanced or retarded slightly. If you're off by one tooth, the truck should run, albeit not optimally. Additionally, the timing marks should line up when the #1 cylinder is at TDC on the compression stroke. Before I tore everything apart, I stuck a (paper-towel-wrapped) screwdriver in the #1 cylinder and eyeballed TDC by rotating crank back and forth slighly. There are a few degrees of crank rotation where the piston is at TDC, so rotating back and forth and splitting the difference will give you actual TDC. Low and behold, this puts the timing mare on the crank pointing at 0 degrees straight up. Index the cam from there.
Regarding ignition timing and max compression, max compression is achieved at TDC, not before or after top dead center. The purpose for igniting the air/fuel mixture ahead of TDC is to allow time for the flame front to propogate from the spark plug and maximize combustion efficiency for a given piston (engine) speed. The faster the piston is moving, the more advance you want in the ignition timing, the slower, the less advance. Keep in mind also that cam rotates at twice crank speed.

2) Replace the chain. No question. Even if it wasn't stretched during the breakage of the nylon guide, many miles of operation make it sloppy. Don't use a claw hammer for getting oil pan off. Use something thin and wide like a putty knife. This will minimize chances of ruining the bottom of the block surface. While you have the pan off, it might be a good time to degrease it, clean it, and repaint it. Freshly painted/cleaned oil pans are great blank canvases to look out for oil leaks.

3) I doubt the chain skipped a tooth while you were tightening cam bolts....more likely it was the guide or tensioner breaking...but lets hope not.

Hope this was a help. Good luck.

Tim

BoltBrain · Sep 10th, 2008, 08:35 PM

Thanks for the reply, Tim. I did put a screwdriver in there (and shone a flashlight in) to make sure it was top dead center. Took the front cover off again (last week, I haven't worked on it lately) and reset the timing by hand again. It still won't start.
I could have bent some valves when I had the chain off and was turning the crank by hand. Should check the compression (as soon as I get to town and buy the tester)
This is a 4WD Nissan King Cab so the distrib shaft actually connects with a shaft on the oil pump, which runs off the crankshaft. There is really only one way to put it in correctly - the marks are plain to see and the Haynes manual tells how to line them up.
I'm probably gonna break down and hire a mechanic one of these days.
Bolt

P.S. My neighbor said i could have it set up on the wrong stroke. ie: exhaust instead of ignition. I don't see how but who knows, I'm doing something wrong

EhBrah · Sep 15th, 2008, 01:11 PM

Sorry my reply may not be timely but assuming your truck KA24 uses the same timing chain as the one in the Stanza the cam and crank sprockets have a mark or dimple. The timing chain will have two links which are a different color than all the others, perhaps a dark color or gold. These two links match up to each mark on the sprocket, when they are the timing is correct. If you don't want to reinstall the chain or cannot find the two marked links, then do this.

1. Note the link on the mark on either sprocket
2. Count the number of links between the first sprocket to the next sprocket mark
3. Not counting the last link on the mark itself, there should be 19 links between each mark

I can post a picture if needed. Been meaning to post a bunch of pics but haven't gotten around to it.

EhBrah · Oct 14th, 2008, 04:32 AM

Would someone help me out and post a pic of the vacuum line connections on the two hoses coming off the crank pulley end of the intake manifold to the two hard lines bolted on the strut tower. One of them has a check valve (looks like a disk) inline. I can't remember which one goes to which port/tube.
Thank in advance.