ignition distributor in bits, why only 8 degrees rpm advance?

[Horsebox]

I only get about 8 degrees rpm advance (vac disconnected) total before it tops out and stays at 8 degrees.

I have taken the intake off and the ignition distributor is in bits - I was hoping to find an obvious culprit in the ign distributor but it all seems ok at first look.

Anything obvious I should do/check? Pain in the backside getting this far in.... only to find nothing obviously wrong. Grrr!

[DMCMW Dave]

Anything obvious I should do/check? Pain in the backside getting this far in.... only to find nothing obviously wrong. Grrr!

How high did you get the RPM? There are two stages to advance and sometimes a bit of a dead spot before you see the second one kick in. Make sure that the mechanism isn't sticky, since you have it this far apart completely de-grease and re-grease it.

[Bitsyncmaster]

How high did you get the RPM? There are two stages to advance and sometimes a bit of a dead spot before you see the second one kick in. Make sure that the mechanism isn't sticky, since you have it this far apart completely de-grease and re-grease it.

+1

Pull on those weights and see if they are sticky.

[Horsebox]

Advance tops out at 8 degrees at about 2000 rpm, then it stays at 8 no matter how much more I rev the engine.

I've lubricated the weights and mechanism inside. There was certainly resistance when I moved the weights outwards but I wouldn't really describe it as binding.

Thanks guys, will see if that has any effect.

[David T]

Advance tops out at 8 degrees at about 2000 rpm, then it stays at 8 no matter how much more I rev the engine.

I've lubricated the weights and mechanism inside. There was certainly resistance when I moved the weights outwards but I wouldn't really describe it as binding.

Thanks guys, will see if that has any effect.

Does your car have the original distributor? Has it ever been removed or tampered with? Was the impulse coil ever replaced?

[Horsebox]

Don't know if it's the original distributor or not, but it's the correct Bosch part number for the D. Someone's got at it in the past though as the dust cap was missing inside. Don't know if the coil has been replaced or not but the resistance checks out at 590 Ohms so I'm assuming it's good (according to a post from DMCMWDave on another thread).

Although according to M:01:04 "induction coil resistance should be 895 - 1275 Ohms". Isn't that what I measured at 590 Ohms? I'm a bit confused about that.

I guess my only option once it's back together and running, if not fixed the rpm advance, is to replace the entire distributor. Ouch for wallet and ouch for having to take the intake off again :thumbdown:

[DMCMW Dave]

Although according to M:01:04 "induction coil resistance should be 895 - 1275 Ohms". Isn't that what I measured at 590 Ohms? I'm a bit confused about that.

I guess my only option once it's back together and running, if not fixed the rpm advance, is to replace the entire distributor. Ouch for wallet and ouch for having to take the intake off again :thumbdown:

The coil issue has nothing to do with the advance issue. 590 is fine.

[David T]

The coil issue has nothing to do with the advance issue. 590 is fine.

I asked because the distributor would have it's advance limited if it was part of the Island Turbo kit. Either your car had it at one time or somehow you got one that was modified for the kit. Just a wild guess. No need to buy another, yours can be changed back so you get full mechanical advance. 20 degrees, not 8. While you are at it you should check that the vacuum advance gets you another 20. To see if you ever had the Island kit look for some plugs in the sides of the motor.

[Horsebox]

I asked because the distributor would have it's advance limited if it was part of the Island Turbo kit. Either your car had it at one time or somehow you got one that was modified for the kit. Just a wild guess. No need to buy another, yours can be changed back so you get full mechanical advance. 20 degrees, not 8. While you are at it you should check that the vacuum advance gets you another 20. To see if you ever had the Island kit look for some plugs in the sides of the motor.

This is interesting.

Another reason for taking the intake off was that the vac advance diaphragm leaked, wouldn't hold a vacuum. So I've replaced it with a working diaphragm. I tested its operation with a hand pump and gauge and it moves the base plate, I guess, as it should.

At some point in the past the car has been owned by someone who knows what they're doing. Some of the prone-to-cause-problems electrical circuits have been taken off the stock fuse box, and been given their own. Other PO mods are comical.

DaveT can you elaborate on what I should be looking for in terms of "plugs in the side"?

Thanks guys, this is really useful.

Mark

[David T]

This is interesting.

Another reason for taking the intake off was that the vac advance diaphragm leaked, wouldn't hold a vacuum. So I've replaced it with a working diaphragm. I tested its operation with a hand pump and gauge and it moves the base plate, I guess, as it should.

At some point in the past the car has been owned by someone who knows what they're doing. Some of the prone-to-cause-problems electrical circuits have been taken off the stock fuse box, and been given their own. Other PO mods are comical.

DaveT can you elaborate on what I should be looking for in terms of "plugs in the side"?

Thanks guys, this is really useful.

Mark

To install the Island Turbo kit you had to drill and tap 2 holes, one on each side of the block, next to the oil pan rail, about 6 inches from the rear of the motor. You should see 3/8" plugs in the block. They were the oil return from each turbo. This would ONLY have been done for the Island Turbo kit and if the kit was removed the holes MUST be plugged.