BX 14 - a little knowledge can be a dangerous thing

Mike Holdstock · Post by **Mike Holdstock** » Sun Aug 09, 2009 9:15 pm

BX 14 was running very well now very high idle speed.

So it was running very well - but for a tendency when accelerating / deaccelerating (push on respectively eae of on accelerator) to jerk a bit. Which I have been working on for a while. I had changed out what was clearly a blown vacuum unit on the distributor - you could blow through it, membrane punctured/rotted - but no improvement.
The local knowledgeables have all pointed at a "magnet valve" which is think may be a Swedish special. the pipe between the distributor vacuum unit and the carb takes a trip via a unit (front right) which is connected to a cable going... somewhere.
So, after disconnecting the battery earth, I pulled the contact off magnet valve - and it was grubby, so I blew some WD in and reconnected it and then the battery.

No change in the lumpiness so far noted, but I do have a very high idle speed.
(and overheating, but I think thats more because the leads to the sensor on the rad are very tired).

Looking at the carb set up on the 14 - there is no idle screw (apparently) but something at its end of travel that is connected to something electric. I have a memory of this thing having hung before - result very high idle speed.

I suppose I should learn that if its working (more or less) not to try to fix it...
Any words of wisdom gentlemen?

Mike

Mike Holdstock · Post by **Mike Holdstock** » Mon Aug 10, 2009 1:30 pm

Sorted now.
I remembered the old trick - if you have possible ECU related problems - of just disconnecting both poles of the battery and allowing the ECU to recover overnight from the shock!
Idle now normal.
The vacuum-related advance/retard is now working,
as is the fan which, yes, had some corroded contacts.

Cheers

Mike

MULLEY · Post by **MULLEY** » Mon Aug 10, 2009 1:36 pm

A 1989 14re with an ECU

Mike Holdstock · Post by **Mike Holdstock** » Mon Aug 10, 2009 2:05 pm

I THINK there is a "black box" under the right right front seat.... Excuse my ignorance, maybe I am using the wrong description. ECU = Electrical Controm Unit or?

Mike

Post by **Tim Leech** » Mon Aug 10, 2009 3:26 pm

MULLEY wrote:A 1989 14re with an ECU

I was thinking the same thing My 14 hasnt even got an automatic choke!

Mike Holdstock · Post by **Mike Holdstock** » Mon Aug 10, 2009 3:58 pm

Even the humble 14RE has an ECU here (if I have the correct name for the black box under the right front seat).
I think this was a result of the Swedes trying to outdo California in emission control, and trying to keep anything but Volvo and SAAB off the roads. In order to get the BX14 licenseable on the Swedish roads they had to put in the ECU.
Results in extra bits and peices here and there, like the carb-distrib vacuum pipe, which I was playing with yesterday evening, doing a detour via a magnet valve attached to the ECU (and surely some other items).
And I do have an automatic choke.
And a lot of engine bits related to timing, carburettion and so on that do not appear in Haynes.

Mike

citronut · Post by **citronut** » Mon Aug 10, 2009 6:26 pm

Mike
if you have an ECU then it will more than likely have a single point injection system, not a carb, the same as the saxo with the TU engine has the single point injection,

regards malcolm

MULLEY · Post by **MULLEY** » Mon Aug 10, 2009 7:56 pm

Mike, when you said ECU, i thought you meant the engine ECU? Since you mention "the carb-distrib vacuum pipe" your car must have a carburettor engine, so it wouldn't have an engine ecu.

I've got no idea about what is in the black box underneath the seat, perhaps you can open it up & take a photo so that the techies can advise what it might actually do?

Way2go · Post by **Way2go** » Mon Aug 10, 2009 8:22 pm

MULLEY wrote:Mike, when you said ECU, i thought you meant the engine ECU? Since you mention "the carb-distrib vacuum pipe" your car must have a carburettor engine, so it wouldn't have an engine ecu.

I've got no idea about what is in the black box underneath the seat, perhaps you can open it up & take a photo so that the techies can advise what it might actually do?

Mulley, he does mean ECU for the injection system he must have to comply with the Scandinavian exhaust emission control requirements.

You cannot run a Cat with a Carb as it would quickly kill it!

MULLEY · Post by **MULLEY** » Mon Aug 10, 2009 8:30 pm

I'm very confused, i cant see any mention of the car being a fuel injected model or that there's a cat either, infact Mike mentions carb related parts more than once.

Mike, put me out of my misery, does your's have the monopoint fuel injection system with a catalitic convertor?

Infact, from memory, my dad's mk1 16trs from 1986 would have had a carb engine & i think that might have been fitted with a cat (this was a swiss specification car)? Or am i talking cobblers

I do know that my Dad's cx has a cat fitted, again its a swiss specification model.

jonathan_dyane · Post by **jonathan_dyane** » Mon Aug 10, 2009 8:34 pm

Way2go wrote:You cannot run a Cat with a Carb as it would quickly kill it!

Not for want of trying; Lada Nissan and I believe Rover all, for a time, sold cars with a carb and a cat.

I believe getting an MOT with these (mercifully) rare beasts could be something of a challenge.

Mike Holdstock · Post by **Mike Holdstock** » Mon Aug 10, 2009 8:48 pm

Just at the moment I am trying to get my ignition key problems sorted without having to turn to the local mechanics at 60£ an hour - see another subject - but I will, from my misery, help to put you out of yours

There is definately a cat - flat lump in the exhaust system before the two big round lumps

I am really a technical non-starter, but I am sure that the 14RE has a carbeurettor and not an injection system (if I want to know what an injection system looks like I look at the GTi)

There is a clear inlet manifold on the bulkhead side of the engine, exhaust manifold towards the radiator.

What I have been referring to as an ECU is a black plastic box under the right front seat, not very accessible, with some chunky cable feeds and plugs going into it.

The local MOT usually doesn't cause too many problems on the emission front - they seem to have got it right and the system is still working. My car has its 20th birthday - according to the ORGA number - on the 20th of August

Does that help to clear the confusion?

And if anyone knows about ignition key fixes, please speak NOW!

Mike

Way2go · Post by **Way2go** » Mon Aug 10, 2009 8:49 pm

MULLEY wrote:I'm very confused, i cant see any mention of the car being a fuel injected model or that there's a cat either, infact Mike mentions carb related parts more than once.

Do you understand the technology of Exhaust Emission Control Mulley 'cos Mike Writes:

Mike Holdstock wrote:Even the humble 14RE has an ECU here (if I have the correct name for the black box under the right front seat).
I think this was a result of the Swedes trying to outdo California in emission control

Anyway even if you dont have a carburetter you still need a throttle body with the butterflies etc so I believe you will find that is what Mike is generically referring to as his "carb".

Mike Holdstock · Post by **Mike Holdstock** » Mon Aug 10, 2009 8:59 pm

I'll talk to the guys round here who know what they are doing - I have two reliable and increasingly wealthy mechanics - about this business with carb, injection etc. I know I have heard the word monopoint used, but thought it was ref distributor and timing.

Mike

citronut · Post by **citronut** » Tue Aug 11, 2009 7:06 pm

a monopoint injection system dose look a bit like a carb to the un mechanicly minded, and it dose sit on an inducktion manifold which looks like a carb manifold, just look at a saxo with the TU engine,

regards malcolm