Timing Woes, I am certain that I am making this more difficult than necessary Options

[ctc911ctc]

All,

So, I have done this only once before on a VW in '72. SO I am really new at this.

With my '74 2.0L that I am currently working on I am having a great deal of difficulty having certainty as to the timing.

I read and re-read the Birdboard entry on this. Did not disconnect the vacuum first time and now since I know better I thought I would try again.

I used the template to mark the fan at 2.x inches to the left (as viewed from behind the car) of the TDC mark (which is a CIRCLE on this fan) and I found a small notch at the 2.x mark - I marked the blades on either side of this mark with White out to assist in finding it while it is moving.

Warmed up the car and set the timing light to 0-degrees advance. Started the car (vacuum removed and plugged) and started to look at the advance. At idle (still chasing this, cannot get it below 1100/1200) the advance 27deg timing mark is very close to the NOTCH. At higher RPMS the 27deg mark is not close to the notch.

The car is running good - though I am chasing two issues.
1. Running very rich, I may still have a vacuum leak, have replaced near everything with exception of plenum and the connecting gaskets to the intake (next on the list)
2. Idle too fast - Throttle body set screw is in all of the way, too much bypass, need to find the leak. Most likely this is part of the #1

So here are my timing Questions:

1. In the chart below, is there correlation between cars (year/engine) and distributor numbers? Kinda weird that it was put into the Birdboard instructions on this topic with no references to it.

2. If I set the dwell angle on my timing light to the degrees of each of the RPM's might it be easier to find which way I need to go advance? retard? or do we just 'play with it'

3. Is it common to get shocked by the plug wires (they are new) while adjusting this thing while running? BZZZZIP (need an electrocuted emoticon here)

Many Thanks in Advance: Love this Board; CTC911CTC

[jcd914]

You should not be getting zapped by the plug wires.

If you marked the fan correctly and your mark shows up at idle the timing is too far advanced. Hold the engine RPM at 3000 and adjust timing so your mark lines up.
Turn the distributor body clockwise to retard the timing and counter clockwise to advance it.
Don't worry about the timing at all the different RPM listed in the chart unless you have so running issue you think are due to poor time at a specific RPM.

When your timing is correct you can start working on the idle and fuel mixture.
Too advanced timing will push idle speed up.

How are you measuring mixture to determine it is too rich?
Incomplete combustion can smell very rich when it is actually not overly rich but not burning the fuel for some other reason.

Good luck
Jim

[ctc911ctc]

You should not be getting zapped by the plug wires.

If you marked the fan correctly and your mark shows up at idle the timing is too far advanced. Hold the engine RPM at 3000 and adjust timing so your mark lines up.
Turn the distributor body clockwise to retard the timing and counter clockwise to advance it.
Don't worry about the timing at all the different RPM listed in the chart unless you have so running issue you think are due to poor time at a specific RPM.

When your timing is correct you can start working on the idle and fuel mixture.
Too advanced timing will push idle speed up.

How are you measuring mixture to determine it is too rich?
Incomplete combustion can smell very rich when it is actually not overly rich but not burning the fuel for some other reason.

Good luck
Jim

Jim, first good advice, the zapping must be an incomplete circuit. Will check the wires.. As a EE I should know this, however, putting theory into practice is a scary thing... (IMG:style_emoticons/default/biggrin.gif)

The exhaust is way too rich, smells of gas. I have:

New injectors
New plugs
New hoses
New MPS
New Decel
Perfect fuel pressure
Vacuum is running at 15, but the RPMs chase this pressure - as designed

Next step is Vacuum after i get the timing done.

Will report back tomorrow - the Clock-Wise/Counterclockwise is very helpful!

[76-914]

So you have a new MPS or a rebuilt one? Was it calibrated? Which plug wires are installed? 1200 rpm isn't unreasonable but if you believe that you do indeed have a vacuum leak: When you re-installed the injectors I assume you used new seals but double check that the injector isn't canted to one side. Easy to do but hard to see unless your looking for it. Have you checked the seal beneath their fill tower? Are the rubber intake couplings supple or hard and dry. New intake gaskets? The shaft on the throttle body can wear with use and allow air to enter thru the shaft bushing. The air box/plenum that the throttle body bolts to is known to rust out in places and can be filled with water or alcohol to check for leaks. (IMG:style_emoticons/default/beerchug.gif)

[ctc911ctc]

So you have a new MPS or a rebuilt one? Was it calibrated?

I rebuilt it using the Tangerine parts, Inductive and bench vacuum tests are the same as a used spare I bought which operates to spec

Which plug wires are installed?

All of them, bought the plug wires from Pelican.

1200 rpm isn't unreasonable but if you believe that you do indeed have a vacuum leak: When you re-installed the injectors I assume you used new seals but double check that the injector isn't canted to one side.

Funny, the number 1 cyl injector seemed canted - removed and reseated. No Change


Easy to do but hard to see unless your looking for it. Have you checked the seal beneath their fill tower?

Yes, took off the fill tower (is that what it is called?) and cleaned the fill tower box, cleaned the PCV and reworked the gasket with auto/aviation gasket seal until the replacement comes - no change

Are the rubber intake couplings supple or hard and dry. New intake gaskets?


Next step, have them - not installed yet

The shaft on the throttle body can wear with use and allow air to enter thru the shaft bushing.

Rebuilt the throttle body, have an extensive post on this, seemed to be firm and no play


The air box/plenum that the throttle body bolts to is known to rust out in places and can be filled with water or alcohol to check for leaks. (IMG:style_emoticons/default/beerchug.gif)

Next stop will be to replace the intake gaskets and to inspect the bottom of the plenum------THANK YOU FOR THE POINTERS!

[ctc911ctc]

Jim,

Using your advice I was able to get the timing set correctly - the distributor was 10-15 degrees too advanced. THANK YOU,

Also, did not get zapped!

The idle came down to 500 from 1200/1400 but the car is still WAY too rich. Next stop I will work on the vacuum leaks (manifold - intake- gaskets) and then inspect the plenum.

If that does not work, I will check the injectors again - I had them setup by a local injector-pro called Hurst Injectors, really good guy with years of Bosch experience.

Any ideas are welcome!

Respectfully,
CTC911CTC

You should not be getting zapped by the plug wires.

If you marked the fan correctly and your mark shows up at idle the timing is too far advanced. Hold the engine RPM at 3000 and adjust timing so your mark lines up.
Turn the distributor body clockwise to retard the timing and counter clockwise to advance it.
Don't worry about the timing at all the different RPM listed in the chart unless you have so running issue you think are due to poor time at a specific RPM.

When your timing is correct you can start working on the idle and fuel mixture.
Too advanced timing will push idle speed up.

How are you measuring mixture to determine it is too rich?
Incomplete combustion can smell very rich when it is actually not overly rich but not burning the fuel for some other reason.

Good luck
Jim

[914_teener]

Ok...so since you asked, questions:

What ECU # are you using?

What MPS # are you using?

What MPS # number did you test the calibration against?

What Dizzy # are you using?

How did the injector expert "set up" your injectors?

How did he test the injectors?

What fuel pressure is "perfect".

Are your valves adjusted properly?





Suggestions:

Make sure you have matched D-jet setup with your components.
Make sure your distributor is completely clean...all electrical components including the advance plate are move freely and work properly. Make sure you test each side of the dizzy vac and retard diaphragms are not leaking. Check your trigger points as well for wear ect.

At idle, there would be no other reason you are rich than the ECU is not matched or you have a vaccum leak somewhere. You don't state why you think you are running WAY to rich.

I also think about swapping out a good known ECU if the # is the right and matched to your MPS after checking all of the above.

Edit:

After all of the above check the resistance spec of the CHT.

[ctc911ctc]

Thank you for looking over my shoulder - need this sanity list!!!

Ok...so since you asked, questions:

What ECU # are you using?


I have 2 of these: 039 906 021, both work seemingly the same

What MPS # are you using?

039 906 051 - I have 2 of these as well. Both have the same calibration. The one that came with the car I blew it out when I first tested it for vacuum, my vacuum gun was set to pressure and the MPS would not hold 15 lbs positive........grin........so then I bought the tangerine kit. put it together and calibrated it as per directions.

What MPS # number did you test the calibration against?

I tested the two against each other as well as checked them against this set of instructions:
https://members.rennlist.com/pbanders/manif...ration%20Curves





What Dizzy # are you using?

Going to have to get back to you on this, the car was a garage find, assuming it is the original (car has 20K on it) but will verify.


How did the injector expert "set up" your injectors?

See the attached below.

How did he test the injectors?

He uses an ASNU machine, also the dude was a Bosch employee (in Germany) for many years. Good guy, very knowledgeable,

What fuel pressure is "perfect".

29 - rock solid, refurb tank, connectors, stainless gas lines, new pump, filter and all hoses, connectors, etc.


Are your valves adjusted properly?

As per the instructions on the Bird Board, checked them twice, sounds good!



As to the richness, the odor is gas-rich and there is smoke (gray) coming from the pipes....VERY RICH.

Going to look at plenum and change manniford gaskets this weekend, will report back to you,

Many thanks,

CTC911CTC




Suggestions:

Make sure you have matched D-jet setup with your components.
Make sure your distributor is completely clean...all electrical components including the advance plate are move freely and work properly. Make sure you test each side of the dizzy vac and retard diaphragms are not leaking. Check your trigger points as well for wear ect.

At idle, there would be no other reason you are rich than the ECU is not matched or you have a vaccum leak somewhere. You don't state why you think you are running WAY to rich.

I also think about swapping out a good known ECU if the # is the right and matched to your MPS after checking all of the above.

Edit:

After all of the above check the resistance spec of the CHT.

[ctc911ctc]

Thank you for looking over my shoulder - need this sanity list!!!

Ok...so since you asked, questions:

What ECU # are you using?


I have 2 of these: 039 906 021, both work seemingly the same

What MPS # are you using?

039 906 051 - I have 2 of these as well. Both have the same calibration. The one that came with the car I blew it out when I first tested it for vacuum, my vacuum gun was set to pressure and the MPS would not hold 15 lbs positive........grin........so then I bought the tangerine kit. put it together and calibrated it as per directions.

What MPS # number did you test the calibration against?

I tested the two against each other as well as checked them against this set of instructions:
https://members.rennlist.com/pbanders/manif...ration%20Curves





What Dizzy # are you using?

Going to have to get back to you on this, the car was a garage find, assuming it is the original (car has 20K on it) but will verify.


How did the injector expert "set up" your injectors?

See the attached below.

How did he test the injectors?

He uses an ASNU machine, also the dude was a Bosch employee (in Germany) for many years. Good guy, very knowledgeable,

What fuel pressure is "perfect".

29 - rock solid, refurb tank, connectors, stainless gas lines, new pump, filter and all hoses, connectors, etc.


Are your valves adjusted properly?

As per the instructions on the Bird Board, checked them twice, sounds good!



As to the richness, the odor is gas-rich and there is smoke (gray) coming from the pipes....VERY RICH.

Going to look at plenum and change manniford gaskets this weekend, will report back to you,

Many thanks,

CTC911CTC




Suggestions:

Make sure you have matched D-jet setup with your components.
Make sure your distributor is completely clean...all electrical components including the advance plate are move freely and work properly. Make sure you test each side of the dizzy vac and retard diaphragms are not leaking. Check your trigger points as well for wear ect.

At idle, there would be no other reason you are rich than the ECU is not matched or you have a vaccum leak somewhere. You don't state why you think you are running WAY to rich.

I also think about swapping out a good known ECU if the # is the right and matched to your MPS after checking all of the above.

Edit:

After all of the above check the resistance spec of the CHT.

(IMG:style_emoticons/default/icon_bump.gif)

[ctc911ctc]

Took off the entire upper assembly to chase the vacuum leaks. My impression of this exercise is:

If the engine has not been running for over 10 years - EVERYTHING in the vacuum chain should be removed and regasketed.



Plenum does not have any holes from rust nor do the seam welds have any leaks - used solvent to chase the tiny leaks - not sure how I was supposed to plug all of those holes to pressure test this, has anyone done that?





My son went nuts on the pipes - really looks great - we are going to put clear coat on this , paint would be a sin.




I also took the opportunity to send all of my injectors back to Hurst Injectors, Paul wants to take another look at them, as well as recondition the ones that I recently purchased. At the end of this job I will have spares of EVERYTHING!

[Olympic 914]

Took off the entire upper assembly to chase the vacuum leaks. My impression of this exercise is:

If the engine has not been running for over 10 years - EVERYTHING in the vacuum chain should be removed and regasketed.



Plenum does not have any holes from rust nor do the seam welds have any leaks - used solvent to chase the tiny leaks - not sure how I was supposed to plug all of those holes to pressure test this, has anyone done that?

Yes chased a vacuum leak for a bit. it ended up being the tubular supports that run through the plenum. Used pipe plugs for the intake connectors and cut a piece of gasket material without a hole and bolted on the throttle body to seal that area. used hoses with bolts to seal the others.

[ctc911ctc]

WOW - very impressive, I could not see any seeping from those weld points - will let this thread know the outcome after I remount all of the hardware.

Took off the entire upper assembly to chase the vacuum leaks. My impression of this exercise is:

If the engine has not been running for over 10 years - EVERYTHING in the vacuum chain should be removed and regasketed.



Plenum does not have any holes from rust nor do the seam welds have any leaks - used solvent to chase the tiny leaks - not sure how I was supposed to plug all of those holes to pressure test this, has anyone done that?

Yes chased a vacuum leak for a bit. it ended up being the tubular supports that run through the plenum. Used pipe plugs for the intake connectors and cut a piece of gasket material without a hole and bolted on the throttle body to seal that area. used hoses with bolts to seal the others.

[ctc911ctc]

Here is what we did this weekend while chasing down the vacuum leak. Most of this was done by my 17yr old who is constantly seeking perfection.


(IMG:style_emoticons/default/smilie_pokal.gif)