Hi gang, since doing my inlet manifold all seems OK now EXCEPT:-

Occassional plumes of light grey/white smoke emitting from the exhaust...

The car starts and runs fine, and the usual whisps of early morning vapour accompanied by the lovely V8 burble emitting from the exhaust.

Later in the journey (as the car warms up) it will suddenly emit a large cloud of white/light grey smoke when pulling away, and a steady stream thereafter.

Stop the car and let it idle, all appears normal, then a little later, it's like James Bond's car with its smoke screen....

Any ideas? Jay

Hey thanks ramon, that sounds very promising, where on the transmission is this modulator, and where does it attach to the manifold?

I remember being concerned about a rigid small bore pipe which connects to the back of the manifold, to a union which looks like a big nut, also attaches to the flexible hose which goes to the cruise control unit. Could this be it?

The carb cars seem to have a more complicated inlet manifold pipe and tube system and to me a minefield to ensure I get at the right one.

Much appreciated Ramon, I wish I was just half as knowledgable as you....

Regards

Jay

Would agree with the diagnosis, look there first

Jay, I am really only familiar with Efi vdp cars with GM180 transmission and from what you say if your cruise is connected to the manifold then it has DANA cruise control rather than HELLA as the latter does not connect to the manifold as it has its own independant vacuum pump.

That probably means you have an early car with a BW transmission and I dont think BW boxes had a modulator valve??.

It would be better to know what you have.

Anyway, IF you have a GM180 box then the modulator valve at the rear must be connected to the manifold via a small bore steel pipe and two rubber elbows. I dont know where on the manifold for a carb car.

Also if you have Hella cruise then someone has ERRONEOUSLY connected it to the manifold that could be fun??

Ramon

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JayDeeVDP wrote:

Hey thanks ramon, that sounds very promising, where on the transmission is this modulator, and where does it attach to the manifold? I remember being concerned about a rigid small bore pipe which connects to the back of the manifold, to a union which looks like a big nut, also attaches to the flexible hose which goes to the cruise control unit. Could this be it? The carb cars seem to have a more complicated inlet manifold pipe and tube system and to me a minefield to ensure I get at the right one. Much appreciated Ramon, I wish I was just half as knowledgable as you.... Regards Jay

Thanks Ramon and Royston,

My car is a 1983 Y-reg series 2, registered January 1983, Rimmer Brothers list the BW66 as 80-83, and the GM180 as 83-on hence I'm slap bang right in the middle??

However...

I have checked my service history and documentation, and I have the GM180 supplement which supercedes all previous automatic transmission documentation.

Also Ramon, I believe I have that narrow bore rigid pipe you mention, it rises in an arc from (somewhere deep) around the centre of the bulkhead area adjacent to where the two rubber pipes which disappear to the heater matrix are, and this pipe is a push fit onto a connector on the rear centre(ish) of the manifold, and there is a little rubber sleeve which protects (and presumably seals) this push fit connection. This little rubber sleeve is actually a little split I remember being aware of this rigid small bore pipe when removing the inlet manifold as I could not bend or fold it out of the way like the rubber pipes when easing the manifold off the engine.

I also feel sure I have the Dana cruise as the operating switch is cylindrical rather than cuboid.

Hopefully with this evidence, I have the GM180, and therefore ~touch wood~ a modulator valve to take the blame for this problem.

Thanks again for all your valued advice and assistance.

Jay

Jay,
That vacuum line is important for 2 reasons.

1 it operates the modulator valve which controls how the gearbox behaves under load.

2 if it leaks air via a split rubber or breached modulator membrane it affects mixture control adversly or sucks out ATF respectively.

Test as follows

remove connection from manifold and attach a small bore rubber tube to the pipe.

Suck on the pipe.

if it will not hold a vacuum the pipe is breached.

If you get a mouthful of ATF the modulator is Knacked

Ramon

JayDeeVDP wrote:

Thanks Ramon and Royston, My car is a 1983 Y-reg series 2, registered January 1983, Rimmer Brothers list the BW66 as 80-83, and the GM180 as 83-on hence I'm slap bang right in the middle?? However... I have checked my service history and documentation, and I have the GM180 supplement which supercedes all previous automatic transmission documentation. Also Ramon, I believe I have that narrow bore rigid pipe you mention, it rises in an arc from (somewhere deep) around the centre of the bulkhead area adjacent to where the two rubber pipes which disappear to the heater matrix are, and this pipe is a push fit onto a connector on the rear centre(ish) of the manifold, and there is a little rubber sleeve which protects (and presumably seals) this push fit connection. This little rubber sleeve is actually a little split I also feel sure I have the Dana cruise as the operating switch is cylindrical rather than cuboid. Hopefully with this evidence, I have the GM180, and therefore ~touch wood~ a modulator valve to take the blame for this problem.

Thanks again Ramon....

I feel sure the tree we are barking up is the correct one, I'm just about to try the test. ~cringes~ I hope ATF doesn't taste too bad.

Sorry to be a pain, but can anyone help me with this.....

I've looked at the Rimmers site and they list two items which sound like "Modulator Valve"

One is item number AEU2812 which is a modular kit @ £104.58,

and

The other is item number AEU2814 which is a modulator valve @ £38.00


Is the latter (ie cheaper) part sufficient, or do I have to obtain the complete kit?

Jay (aka Confused.Com )

Yes Ramon, thank you indeed.

I removed the pipe as you suggested, and I didn't need to suck on the pipe, there was lovely pink fluid oozing gently from the end....

Confirmed therefore, new modulator valve required, brilliant!! (relieved....)

I wonder how many engines have been wrongly condemned over the years when this fault occurs.

Question now chaps is....

Which part do I order (please see my previous entry)?

I think it would just be the 2814 valve but you should be able to get a good SH unit from guys like Ian Taylor, at RSC.

Ramon

JayDeeVDP wrote:

One is item number AEU2812 which is a modular kit @ £104.58, and The other is item number AEU2814 which is a modulator valve @ £38.00 Is the latter (ie cheaper) part sufficient, or do I have to obtain the complete kit? Jay (aka Confused.Com )

Thanks for all your help Ramon, I've gone ahead and Express Ordered a new 'un from Rimmers, because I need the car back on the road asap.

Not looking forward to crawling arond under the car, though

Jay

Thats the good news then. Purely from memory, but I seem to recall removing the modulator valve for replacement/repair involves moving the y piece of the exhaust out of the way.

Hope I,m Wrong.

Ramon


I too hope you're wrong but deep down I'm sure you won't be....

There are a few joints on the exhaust that need sorting anyway, so not too much of a disaster, kill several birds with one spanner...

Wish me luck

Help me someone, please....

Rimmer Brothers tell me part number AEU2814 (Modulator Valve) is not currently available....(£38.00)

Runcorn SD1 Centre have no used ones in stock....

Rimmers also list a Modulator Kit (AEU2812), an eye watering £104.58. Do I have to buy the whole kit for this valve or is the kit something completely different? (I'm not familiar how this component is put together, hence cannot visualise the actual valve or kit)

Jay

PS - Anyone got a spare GM180 modulator valve kicking around?