Thread: 186 Engine problem NEED HELP

Originally Posted by Hoges

Don't forget there's a mechanical advance as well as a vacuum advance on the distributor. Is the mechanical advance operating as it should? The (additional) vacuum advance is required mainly for combustion of lean mixtures produced by a partial and /or trailing throttle...e.g. cruising or on over run down hill etc

From your description it appears that the non revving issue is a combination of timing (incl advance) and carburettor. The lack of revs could well be that the float valve is stuck and the float level is incorrectly set. You need to physically bend the float arm to get the correct level...at the same time keeping the float as flat as possible. There used to be a special tool for this ... a 75mm strip of aluminium 2mm thick and 7mm or thereabouts wide with a 3mm wide transverse slit extending about halfway across the strip from one side and located about 5mm from one end..if that makes sense? You position the slit the over the float arm and bend the float arm against tool rather than putting prressure on the float valve which is a bit fragile.

As advised elsewhere, bend the float while the engine is idling and the vacuum passage is blocked off to get an even idle at 500 rpm and measure the depth of fuel in the float bowl from the top of the bowl without the gasket in place.

One of those thin 6" engineers rulers with a piece of carboard attached as a sliding "saddle" is ideal... slide the ruler down until it just touches the surface of the fuel and slide the cardboard along the ruler to the top of the bowl read off the value... the fuel surface should be 15.8mm or 0.62" below the face of the bowl

(I once had a torana 173 which was for all intents and purposes the same as the 186 engine. One time driving it to Adelaide from Canberra and it would not do more than 45 mph across the Hay Plains Any faster and it would cough and almost stop but cruise all day at 45mph... it was only 6m old! Sure enough it was a dud float valve setting which I managed to fix with a small metal ruler in the basement carpark of the pub we were staying at... It cruised at twice that speed going home but that was >40 yrs ago Lesson learned re. float levels.)

If you can get to a public library... Gregory's Manual#84 on the LC-LJ torana has all the info for all the Holden 6 cyl engines from 138-202.

Couple of other things: get yourself a decent timing light from supercheap and a vacuum gauge for setting the idling screw.... they're indispensible!

Tried checking for air leaks, and the float valve height. No change.

I guess I will have to submit and buy a timing light and vacuum gauge. Wont be happening for a while though cause the bank wont give me any more money.... So looks like we only have 1 car for a couple of months.

My PCV kit turned up, so I fitted that. Still no improvement....

Does anyone live in Mackay and own a timing light?

Ok found a timing light and confirmed that I had the timing correct.

Problem still continues as before! Without the vac advance the engine seem sto run well, revs up to 4000rpm ok. BUT when I connect the vac advance it wont rev above 1000rpm.

I've checked for air leaks in the vac advance hose. and a new pcv kit was installed.

ideas please guys!

Wot I said before about the rotor arm needing to meet the cap terminal under full vacuum still stands. So basically your dissy is a dodgy piece of crap but it runs without the vacuum connected. Solution: either fix the dissy pickup alignment or run it without the vacuum until you can afford a proper dissy. Vacuum advance is not essential to forward motion, it merely adds economy.

gday debruiser.
I hope this helps, but my memory for the red motor is pretty faint...

sounds to me like the vacc advance diaphragm is crook, or possibly it is the wrong distributor for that motor (the reds have been around a long time and there have been plenty of opportunities for people to mix up the parts by now).

If it revs OK without vacc advance then the centrifugal advance (mechanical weights under top plate of distributor) is probably OK.

one way to check the vacc advance would be to put a tube on the vacc advance line and apply gentle vacc to the other end with some kind of suction - you could put a vacc gauge on a T piece in the line to the suction pump (or your mouth!) to see how much vacc is developing. As the vacc level changes I would think you should see the timing mark change with a timing light (this will probably take 2 people).

We had a Supra 2.8i motor (yuk) a little while back that was incapable of moving the car out of the drive even though it would rev OK no load - turned out to be the distributor vacc advance.

Sorry if you already mentioned it but what carby is on yours now?

I had an old 221 Ford once that was fussy about having the right carby and distributor combination (I had been mixing but not matching & it wasn't working!), not sure if that applies to the red motors.

A final idea - if your Landy has power brakes, perhaps disconnect the brake booster vacc line (fairly thick) and plug it to check the engine. My IIA's vacc booster leaks and it all but kills the motor when it's connected - that was OK for a paddock basher but no good for a road car!

These things are great though, keep on keeping on it will work out in the end.

Cheers
Paul.

Originally Posted by pk.hoarder

gday debruiser.
I hope this helps, but my memory for the red motor is pretty faint...

sounds to me like the vacc advance diaphragm is crook, or possibly it is the wrong distributor for that motor (the reds have been around a long time and there have been plenty of opportunities for people to mix up the parts by now).

If it revs OK without vacc advance then the centrifugal advance (mechanical weights under top plate of distributor) is probably OK.

one way to check the vacc advance would be to put a tube on the vacc advance line and apply gentle vacc to the other end with some kind of suction - you could put a vacc gauge on a T piece in the line to the suction pump (or your mouth!) to see how much vacc is developing. As the vacc level changes I would think you should see the timing mark change with a timing light (this will probably take 2 people).

We had a Supra 2.8i motor (yuk) a little while back that was incapable of moving the car out of the drive even though it would rev OK no load - turned out to be the distributor vacc advance.

Sorry if you already mentioned it but what carby is on yours now?

I had an old 221 Ford once that was fussy about having the right carby and distributor combination (I had been mixing but not matching & it wasn't working!), not sure if that applies to the red motors.

A final idea - if your Landy has power brakes, perhaps disconnect the brake booster vacc line (fairly thick) and plug it to check the engine. My IIA's vacc booster leaks and it all but kills the motor when it's connected - that was OK for a paddock basher but no good for a road car!

These things are great though, keep on keeping on it will work out in the end.

Cheers
Paul.

Hi paul,

Thanks for the tips! I've got a new dizzy - there is alink earlier in this thread. so one would HOPE that the vac diaphragm is ok, but then again you never can be 100% sure.

I've got a BXV-2 (from a holden 202) on it atm. I've done a rebuild on it previously but it was still giving trouble so I've acquired a different one - in better condition. I've rebuilt that and I'm going to install it today! we'll see what happens. It had been running OK on the old carbi, just had funny quirks at times.

I might try that suggestion of the brake booster leak. It's worth a shot.

Not sure what distributor your using but the best upgrade is a late model electronic one. Used them on my race motors. Just fiddled with advanced curve. You will have to get the right coil & leads to suit. These dissies were good to about 8000 rpm . No stuffing about setting points etc

And as has already been said check for vaccum leaks

Gary

Rebuilt carbi in. 1 1/2 hrs driving round trying to find a brass fitting to fit the vac advance hose. Now at least I know why the car wont run! It's now the carbi

Soooo is there anyone out there with some petrol engine experience in Mackay? Feel like coming round on the weekend to help sort out my mess? I'm nearly ready to hire a trailer.... to deliver it to someone... can't decide where yet; could be the dump or a mechanic.... probably cheaper to go to the mechanic though.