Timing IP by ear

[ToddA1]

Anyone doing it? 

IIRC, a VW tech told me he would advance the pump until the engine started stumbling, then retard until it smoothed out.  I'm guessing it would be done on a warm engine.

Curious how accurate it would be if verified/checked with a dial indicator.

-Todd

[8v-of-fury]

To be honest, any movement that is seen with the eye is quite significant to what the timing numbers will be. I mean the difference between say a stock setting of like 0.85mm and a performance setting of 1.00mm of advance is more or so a 1/16th of an inch. I'm not saying it isn't possible, its very possible and very easy to do. 3 13mm nuts on the front behind the pulley, and one on the lower back (near the rad hose that snakes down the block) will loosen the pump up IIRC.

Its doable. A lot have done it and run them like that. However it will never be better then accuracy with a dial indicator.
I take that Back
A warm engine would be best, yes.

[maxfax]

It's one of those things that takes some time and experience..   I can't really put it to words in a how too, you just get to know when it sounds right..  And x2 on the warm engine...


When dabbling with mine I'll do the time by ear/trial thing then when I hit it dead on I check it with a gauge (so as to know where to set it again if need be)... It's not surprising that every one of these little buggers seems to be at it's best with a slightly different timing setting..

[8v-of-fury]

It's not surprising that every one of these little buggers has been at it's best with a slightly different timing setting..

I recant what I said Brett, your right.

what I meant to say was.. lol

every pump/engine/injectors are/is different and therefore require more or less advance. No set number value is good for every engine. Just so long as you don't go over board, timing by ear is actually probably the best way to go about it..

[westcoaster]

What's the down side of too much advance? or too much retard?

[maxfax]

You got it Jeremy..   Though I'm not saying throw out the indicator all together..  For those who are just starting out with their rattle trap by all means use the gauge until you have some experience..  And most of the time I will use it to set the timing so that I have a starting point to work from..  Typically a very small bump either way will do the deed after that..

West coaster, generally retarded timing makes for hard starting, low power and economy, and white smoke.. Too far advanced makes them clattery and at a certain point will decrease power and cause rough running...  And neither one is real great for engine life, others I'm sure can chime in with experience on both....

[maxfax]

You cannot beat the pulse adapter and timing light.  Bang on every time, fast and easy...

On my Christmas list!!     

 While we are on timing (Sorry Todd didn't mean to get off topic)..  IS any one familiar with a thingy doo from Snap On called a Lumy Mag??    I got one with a lot of tools years ago, unfortunately I only have GM adapters..   Basically how it works is there is a magnetic probe (on a vw it pops in the plug on the bell housing) and a little lens like thing that screws in the GP hole.. It senses the glow from combustion and the position of the flywheel to give the timing and RPM on a digital readout...

[bugnut]

Speaking of timing by timing light.  What is a number you should be shooting for?  Right now my engine likes 14.75 btdc.  It is a little too much on the top end I can really hear it rattle.  Anything lower than that and it don't run very well.  Would like to hear from others that have there engines timed with the light. 

[Smokey Eddy]

i've always only ever timed by ear. it will let the car run and ease cold starts but its not as good as getting it set really precisely. i advance till i hear a clatter and back off a touch.

[ToddA1]

I timed my pump to 0.97mm and the car ran rough.  I smoothed it out by increasing the idle just a tad, but didn't like the band-aid solution.  Returned the idle screw to original setting and pushed the pump forward a tad for a bit of advance.  Runs was better.

The clacking sounds a bit different, but I adjusted the valves prior to this.  I also haven't had the car running for a few months due to an accident and body repair, so I kinda forget what it sounded like.

Thanks for the replies...  the dial indicator is just for a baseline, from now on.   

-Todd

[Mark(The Miser)UK]

With my timing light I aim for 11.5-12° BTDC.

The pulse adapter reads the actual start of injection from the pulse in the fuel line and so it intrinsically compensates for out of spec injector breaking pressure and some instances of internal pump wear.  It cannot (nor can timing it by ear or indicator) compensate for improper operation of the dynamic advance system.

Interesting data Andrew, but needs a little more information for accurate replication.

Do you use that figure for both N/A and Turbo engines?

Does your timing light read in pump degrees, or crank degrees?

Do you place your transducer at output from pump, or as close as possible to the injector?
 
 What idle speed is that at, and have you noted how it changes at increased rpms; or do you look for dynamic springs to give that advance at the injector for all speeds?

... Well that looks lke a lot more information to me

[bugnut]

Here is what I know about the diesel pulse adapter and the timing light.  I have the snap-on pulse adapter and it says to put the transducer as close to the injector as possible.  With the timing light you hook that up to the pulse adapter and it will show when that injector is firing at the crank.  Put is this way it is just like putting the timing light on a spark plug wire and reading timing that way.

[Baron VonZeppelin]

I timed my pump to 0.97mm and the car ran rough. 

Just to toss one in here - when zero'ing the gauge - and when getting "the reading" at TDC - always take the lash out of the gauge - by pulling out the stem and pushing it back in. Or just push it in.

Everytime i go to check the TDC reading - i have to take the lash out of the gauge every time i stop rotating the engine. If you just ramp up to .97 without removing lash - it will really be about .80

Its such a small increment on these settings that the least bit of ramping changes it drastically. And the engine tends to back up just a hair on initial pulls to TDC - due to the compression. But the gauge will usually stay at where it went highest. You/I/We can be deceived.

I get to the nitty gritty and stay in one mindset when doing pump timing. And never trust just the first reading. I take the reading usually 3-4 times before i call it fact. And always be sure to remove the lash.

And like Maxfax mentions, very good idea to go back and get the reading from an "after ear setting" for future references. It could come in real handy. 

[hooper]

With my timing light I aim for 11.5-12° BTDC.

The pulse adapter reads the actual start of injection from the pulse in the fuel line and so it intrinsically compensates for out of spec injector breaking pressure and some instances of internal pump wear.  It cannot (nor can timing it by ear or indicator) compensate for improper operation of the dynamic advance system.

are you reading this on the flywheel mark? ive tried setting mine to the figures you give above but runs awful,wont start and smokes hard at idle. ive increased the timing to about 14-14.5° and it runs smoother,cold starts ok and runs clean at tickover. the timing light and pulse adapter is great but theres a lack of specific info for set up and was wondering what you thought of timing set at 14.5°. do yo klnow what the idel speed should be set at? im currently running about 950rpm.

[8v-of-fury]

I don't know if there is any definitive numbers for these  engines anymore, as obviously they left the factory 20+ years ago and have all experienced different events, drivers, conditions, fuel, climate, etc. Some may have healthy pumps, bad injectors and good compression, whereas another may have the original pump and injectors, 500,000k on it and just been re-ringed.. It all plays a very significant part. If your car starts and idles fine, accelerates with good power, only has some smoke on start-up and when your haulin' on the go-go pedal, and doesn't run too hot on the temp gauge.. I think your set.