[SOLVED] Vacuum reading interpretation

[EYY]

Psi doesn't matter, as long as they're all within 10% of each other.

 

[greenacc]

Rocker cover is the top of engine and basically just a tin can, so no probs with oil or coolant gushing out you just need a new cork gasket afterwards and bobs ya uncle. (Could be a tiny dribble)
Use the right glue or goo or whatever is recommended too.

 

[strgas]

remove all spark plugs disconnect coil positive , hold throttle wide open , comp test wet and dry , and post results .
if after dry test cylinders are within 10 15 psi of each other then no real need for wet testing , wet test when one or more cylinders seem low in comp . a oil can with engine oil acouple of squirts in each cylinder will improve the sealing of the rings and should improve a low comp reading if the rings are shot , no improvment could mean burnt or sticky valve .

 

[sundaydriver]

@EYY @greenacc @strgas Legends, thanks very much. Will get stuck in tomorrow and post back.

 

[greenacc]

Now I'm just curious, slap me if I've missed something.
You said this motors done about 50,000ks? Is that since new or rebuild?
If somethings been sitting 30years with God knows what oil in it you could have sludge issues or rust etc etc.
A sludged up sticky hydraulic lifter could give you vacuum issues for example
Could also be something simple but this thread could start getting interesting soon

 

[the_boozer]

No it won't, I think you've misinterpreted. I didn't say anything about a spanner

I thought ole mate was trying to turn the motor off that bolt with the plugs in . Try it and see if it doesnt break how do you think I know its easy to break? Anyways all I actually suggested was to advance it up further to see if would run any better I didn't see any point in picking on valves at that time and was wondering why ole mate needed to turn it over by hand at all?

 

[sundaydriver]

@EYY @greenacc @strgas @the_boozer

OK, Gents. Results are in from the pressure test.

Dry (comparing all to the highest - #1)

1. 150
2. 137 (-8.6%)
3. 145 (-3.3%)
4. 140 (-6.6%)
5. 140 (-6.6%)
6. 140 (-6.6%)

Wet (comparing to their dry value)

1. 155 (3.3%)
2. 160 (16.8%)
3. 150 (3.4%)
4. 145 (3.6%)
5. 155 (10.7%)
6. 150 (7.1%)

From what I've read, it doesn't seem too bad. #2 worried me a bit, but it's still ~8% below cylinder 1 dry, and 16.7% better (that itself) wet. So nothing really drastic, right? Or does #2 sound like something?

Where to from here? Still worth taking the rocker off?

Got the Gregory's workshop manual today too - so confirmed the timing (6 degrees btdc), slow (850-900RPM) and fast (2500RPM - scary getting that close to the engine at that RPM, trying to adjust the screw!) idle are all good.

Just going back over some old stuff - all new ignition system (inc. coil and module), confident head gasket is fine, replaced all vac hoses and joints, carby has been rebuilt and new internal and mount gaskets. Haven't replaced the manifold gasket, but done spray tests and no vac change. Haven't done a leak-down test as I don't have the tool or a compressor, but I left the gauge on for about 5 mins when doing each sylinder compression test and there wasn't much change - maybe 5psi drop?

 

[sundaydriver]

I thought ole mate was trying to turn the motor off that bolt with the plugs in.

Yeah, think this was me misunderstanding what @EYY meant. Thanks @the_boozer for stopping me before I sapped the bolt off and took a few knuckles with it!

 

[sundaydriver]

Now I'm just curious, slap me if I've missed something.
You said this motors done about 50,000ks? Is that since new or rebuild?
If somethings been sitting 30years with God knows what oil in it you could have sludge issues or rust etc etc.
A sludged up sticky hydraulic lifter could give you vacuum issues for example
Could also be something simple but this thread could start getting interesting soon

OK, so it was my granddad's. He bought it off the line back in the day and then kicked the bucket shortly after. It has been garaged in his small country town ever since. Regular basic maintenance has been done over the years, to stop the fuel/oil congealing, keep it running and registered. The shops are about 1 kilometer from the garage, so that's all it traveled 5-7 days a *week* (whoops!) since about 1988. So I am guess this would be enough to stop the lifters seizing up, yeah?
So yes, less than 50,000 original kilometers on the clock. All original everything (can you still say that when you replace lead/dizzy caps/oil filters...), no rust, no dings, and more or less like new

 

[greenacc]

Compression figures sound ok to me especially for an old donk from the 80s.
Can you elaborate more about what the problem is that you are trying to solve here? Is it just an idle issue, is the car drivable, does it drive ok other than the idle, does the idle improve as it warms up etc etc.

Just some history on myself for you, my first 2 cars had 202s in them, one was a red motor in a torry and the second a blue 3.3 just like yours in a commy! I still wish I could drive that commy again (and the torry lol) with its comfy as lounge seats and straight six mumbo but she kind of fell apartcat the seams, or at least the traumatic box did and so I put my cash into a much newer model that would be more reliable. But 15 years later I still remember working on those delightful engines and youve made me think how I could find one to have a drive of again, dammit!