TheSamba.com :: View topic - Distributor Out 180 Degrees - How to tell -

Tue Nov 25, 2008 8:45 am

After my post on ways to find TDC (thanks for all the additions), it made me wonder how you tell if one of these engines is 180 degrees off. I see this is posts once in awhile. There was an extra distributor that came with one of our Buses and I noticed that on a VW distributor the notches that line up with the distributor drive are offset, not centered like I had seen on American cars I am used to. It seems like you couldn't put the distributor in 180 degress off if the piston on 1 is at TDC and the rotor is lined up correctly. I am sure my thinking is tainted by my old V8 ways so just trying to learn along with my son. I am guessing I am missing something that may be obvious to those of you who have worked on these for awhile. Thanks in advance. I am not a mechanic, I just try to do all my own work and the VW has been fun but full of new tricks.

Tue Nov 25, 2008 8:49 am

Try swapping out plug wire #1/#3 and #2/#4 on the distributor cap and see how it runs.

Tue Nov 25, 2008 8:52 am

@ #1 TDC look down in the hole. the slot in the dist drive pinion should be perpendicular to the crack in the case and off center towards you.

hope that helps...nice looking ghia.

Tue Nov 25, 2008 9:42 am

Randy in Maine wrote: Try swapping out plug wire #1/#3 and #2/#4 on the distributor cap and see how it runs.
So if that worked, how do you get it back to "normal". I don't want to mess with our engines they are running fine, mostly just on a knowledge search that my 14 year old started. (Good for him) You guys are a great resource. When this runs it's course I'll add a post that combines it with my TDC post.

Tue Nov 25, 2008 10:01 am

I would say that the way to get it correct, the best way would be to re-index the distributor drive to the correct camshaft/crankshaft location. Tough to get it 100% correct unless the case is split.

Tue Nov 25, 2008 12:02 pm

O/

When #1 is TDC, the slot inside the dist shaft will look like the illustration above correct? It is slightly off-centered though. Thanks.

Tue Nov 25, 2008 12:27 pm

one more time:

remove distributor.

borninabus wrote: @ #1 TDC look down in the hole. the slot in the dist drive pinion should be perpendicular to the crack in the case and off center towards you.
firing order is 1-4-3-2. where the wires are oriented other than that does not matter

let's clear up some confusion. is this T1 or T4 engine? my description applies to T1 engine. busmania is referring to a T4 engine.

Tue Nov 25, 2008 4:34 pm

If you ever get the leads mixed up, pull all but 1 leads (leave the lead coming from number 1 cylinder) from the distributor, and try turning the engine on the key. If it doesnt fire keep moving the same lead around the distributor until it does catch on that cylinder. Once it does, its just a case of remembering the firing order 1432 and connecting the leads back on in this sequence.

Tue Nov 25, 2008 9:02 pm

If the dizzy drive gear is installed backwards ( rotated 180 deg. )
then the firing order will not be 1-4-3-2, it will be reversed.

The engine will run fine--it doesn't "know" it's 180 deg. out,
but the spark plug wires are plugged in mirrored on the dist. cap.
from the "stock"/correct arrangement for 1-4-3-2 firing order.

But if it truly is out 180 and you want to fix it, you will need to get the special puller and remove the dizzy drive gear/shaft. There are washers at the bottom which sit in a recess--be CAREFUL not to drop them into the case!!! Also when replacing it, DO NOT force it in or turn the engine very much or it will chew up the soft brass gear and leave chunks of it in the case--and this will ruin your engine!!

There are numerous threads on removing/reinstalling the dizzy drive.
Check/search the forums. My advice is be very careful if removing/reinstalling dizzy drive. :!:

Cheers....

Tue Nov 25, 2008 9:07 pm

cbcarch wrote: If the dizzy drive gear is installed backwards ( rotated 180 deg. )
then the firing order will not be 1-4-3-2, it will be reversed.

The firing order is still going to be 1-4-3-2 even if you install the engine upside down and drive backwards down the road.

Wed Nov 26, 2008 1:47 am

You can call the firing order anything you want. 1-4-3-2, 4-3-2-1, 3-2-1-4, or 2-1-4-3. They are all the same. Just so #1 fires when #1 is at the top of it's compression stroke. The engine and the rotor only rotate in one direction. If the crank pully is at TDC, or "0", it is either at the firing position for #1 or for #3. Either #1 or #3 will be at the top of the compression stroke and the other will be at the end of it's exhaust stroke. So no mater what, if the pulley is at TDC the rotor will be pointing where the plug wire to either #1 or #3 should be plugged in. It's either one or the other. One way it will run and the other way it won't. Assuming that when you look down at the distributor cap all the wires are in order going clockwise. If the distributor drive gear was installed in any position other than the "normal standard" position the distributor will be rotated differently than the "normal standard" position. No difference at all with the way the engine runs but the vacuum canister could be in an awkward location. If the drive gear is installed in the normal position, plug wire #1 will be at 4:30 when looking down at the distributor. That's for a T1, T2, and T4. Even though the drive gear teeth can be installed in a lot of different positions it usually isn't involved with the 180 degree out of time issue. That issue is usually related to someone plugging the #1 wire into the distributor with the crank pulley at TDC but not at the right TDC. Rotate the engine one more revolution until it's at the correct TDC, at the top of the compression stroke.

Wed Nov 26, 2008 8:16 am

Desertbusman,

Thanks for that explanation.
That is exactly what I was (fumbling) and trying to say.

Cheers :oops:

Wed Nov 26, 2008 10:25 pm

borninabus wrote: one more time:

remove distributor.

borninabus wrote: @ #1 TDC look down in the hole. the slot in the dist drive pinion should be perpendicular to the crack in the case and off center towards you.
firing order is 1-4-3-2. where the wires are oriented other than that does not matter

let's clear up some confusion. is this T1 or T4 engine? my description applies to T1 engine. busmania is referring to a T4 engine.

T1

Thu Nov 27, 2008 2:34 am

Make sure the round drive tooth thing on the end of the distributor shaft is not installed 180* off, this will have the same effect. I did this once.....
You need to drive out the pin, and move it 180*. Check this against the drive in the engine. Both should agree with the illustration in your Bentley manual. Although, why would that thing be installed backwards, except by disassembling the distributor.
What, no manual???? :?

Thu Nov 27, 2008 8:44 am

greenbus pilot wrote: Make sure the round drive tooth thing on the end of the distributor shaft is not installed 180* off, this will have the same effect. I did this once.....
You need to drive out the pin, and move it 180*. Check this against the drive in the engine. Both should agree with the illustration in your Bentley manual. Although, why would that thing be installed backwards, except by disassembling the distributor.
What, no manual???? :?
Since ours isnt out 180 degrees I can only se that it is correct and when I read through the Bentley, they don't reall cover 180 degrees off.

Sat May 02, 2009 3:30 pm

I just saw that my distributor is 180 off, too. I was adjusting my valves for the first time and couldn't figure out why I was getting what I now know is the sound of loose valves. It turns out, my mechanic turned the distributor all the way around and swapped the plug wires, while he was trying to solve an ignition problem last year. Is there any reason why I shouldn't try to set it back? It's a SVDA.

Sat May 02, 2009 3:34 pm

It doesn't matter... it will work either way.