Not starting - Timing out?

**tb3** · 14th February 2015, 04:13 PM

Hi all,

Had a search on this matter but could not find anything directly related despite the numerous timing threads.

Long story somewhat shortened - I had the distributor out of my 1990 3.9 motor and lost the positioning of the rotor in relation to the distributor body ie. timing lost. I got the rotor back on track facing lead 1 on dizzy cap when at about 4 deg BTDC static.

Next up, tightened the 15mm nut holding distributor in to still allow for a bit of movement. I tested I was on the ignition stroke but hooking up a spark plug to lead 1 and twisting the dizzy cap to replicate the rotor passing point 1 on dizzy cap. I left the dizzy cap right at the point where it would cause the plug to spark.

Upon cranking her over there are definite signs of life but can not get it to start. Have played around twisting the cap clockwise (retarding) a couple of degrees at a time but not much improvement. I can not try advancing any further (anti-clockwise) as the ignition amplifying module fouls on the motor. The module was just replaced hence the removal of distributor. I have actually had this motor running on this module before. In this position I am still an inch or so off my original distributor body position markings.

I am not sure how long/if the timing chain was replaced as I have only owned her for a couple of years. So the question is - am I to set the static timing to compensate for any slack in timing chain? 330xxx kms on the clock, mostly highway. Lots of compression. Plenty of fuel - can smell it in the cabin and from exhaust pipe when cranking over. Was running fine before this.

Sorry for the long write up - any thoughts feelings or opinions welcome.

Thanks,

Tom.

**bee utey** · 14th February 2015, 04:30 PM

You really need to determine that no.1 cylinder is at TDC on the firing stroke before proceeding. Turn the crank so that the timing marker lines up. Remove no.1 spark plug and using a length of heater hose blow into the cylinder. If no.1 is at the firing stroke a small movement either side of TDC will not let any air leak past the valves. If the engine is 1 turn out then a small movement of the crank will allow either the inlet or exhaust valve to open and your breath will flow easily into the cylinder. Once you've determined you're on the firing stroke move the timing mark to a few degrees BTDC THEN insert the distributor so the rotor points to number one lead. Make sure the oil pump drive is fully engaged before trying to do up the distributor clamp. The pump drive shaft can be easily turned with a piece of tubing squashed somewhat flat. Timing chain wear doesn't require different ignition timing as that relates to the crank position not the cam.

**tb3** · 14th February 2015, 04:39 PM

Appreciate it mate, gives me something to work on tomorrow. Will post back with progress, hopefully.

**tb3** · 15th February 2015, 08:38 PM

Got her going this afternoon after essentially repeating the above process and ending up with dizzy positioning slightly closer to original markings. Motor was on ignition stroke for previous attempts. Heater hose trick in cylinder one worked well.

Playing with dizzy cap position whilst running I can fluctuate the idle revs from 500-1100rpm. At 1100rpm ignition module fouls on motor. Interestingly the exhaust note sounds slightly more "tractor like" after this fiddling? Fuel is now 2-3 months old if that could contribute?

Timing light on its way for further tweaks with addition of new plugs and leads.

**DoubleChevron** · 16th February 2015, 12:54 PM

You need a light ... I'm never sure if I can trust the timing scale on an engine either way .... so that always helps.

If you can't get enough advance, move every plug lead one position further around the cap and drop the rotor back in in the correct spot. You didn't happen to pull the centripetal weights off by pulling on the rotor button did you ?

seeya,
Shane L.

**tb3** · 16th February 2015, 06:13 PM

Good thought - will put that into practice.

Weights all still in tact. Only removed transparent plastic cover to clean and reinstall.

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