FBH The end of the SAGA ? - Page 22

Jakg · 5th March 2016, 21:09

Quote:

Originally Posted by Jakg

Another day, another problem!

When setup as a parking heater, my FBH only ever gets the coolant up to about 55° C at most, even after >20 minutes.

Yesterday I used it and noticed a black patch under the car.

Today I came back (I put it on as I walk my dog) to find a lot of smoke, a smell of diesel and a big sooty patch under the car. The coolant was at 25° C so it'd done something, but I'm not quite sure what!

All I can think of is too little air would cause incomplete combustion = soot?

I serviced the unit only a few months back.

Quote:

Originally Posted by FrenchMike

Hi Jack,

Remove the foam Inside the air inlet and see...

Mike

I removed the foam inlet and it solved my problem, briefly. Then it came back!

I know - I've posted too much in this thread!

Mike - can I post you the PCB? Are you happy to take a look?

FrenchMike · 6th March 2016, 07:18

Quote:

Originally Posted by Jakg

I removed the foam inlet and it solved my problem, briefly. Then it came back!

I know - I've posted too much in this thread!

Mike - can I post you the PCB? Are you happy to take a look?

Hi Jack,

Yes, but i doubt ...(i never encounter this)

Two ways :

too much fuel delivered

Or more plausible your fan is feeble ?

normally it sounds rather like an hovercraft ...

Jakg · 6th March 2016, 07:50

Quote:

Originally Posted by FrenchMike

Hi Jack,

Yes, but i doubt ...(i never encounter this)

Two ways :

too much fuel delivered

Or more plausible your fan is feeble ?

normally it sounds rather like an hovercraft ...

It gets weirder - when I run the unit using the pin whatever test, it runs fine and warms up to 50-something° C, no smoke.

When I start the engine and let it warm up - then it warms up a bit then smoke starts pouring out.

The fact it does differing things in different "modes" of operation was what lead me to think it was the PCB.

HarryM1BYT · 6th March 2016, 08:06

Quote:

Originally Posted by Jakg

It gets weirder - when I run the unit using the pin whatever test, it runs fine and warms up to 50-something° C, no smoke.

When I start the engine and let it warm up - then it warms up a bit then smoke starts pouring out.

The fact it does differing things in different "modes" of operation was what lead me to think it was the PCB.

Just to throw an idea into the pot...

It reads as if it might be completely random. I know you say you have given it a clean out and service, but it is easy to mistake hard burnt on carbon for part of the combustion chamber structure. Make no mistake - burnt on carbon is very hard and will need to be chipped away.

Like FrenchMike, I doubt the PCB is at fault - you need to look elsewhere. As Mike says, it should sound like a small jet engine. The speed of which and noise should gradually ramp itself up, after the combustion becomes established, to full speed. It should then ramp down as it nears shut off temperature.

Any carbon around the glow pin or the mesh at the back could cause the miss-fires you are complaining about.

Union Wheels · 7th March 2016, 09:41

Hi Jakg,
is it possible that the start up voltage to pin 1 of the 6 pin plug is intermittent or low.

I have read somewhere that the wiring between the alternator, temperature sensor and pin 1 of the heater can become corroded near to the temperature sensor plug.

Just an idea, Pete.

Jules · 7th March 2016, 10:01

FBH Golden rules recap

Most common later type 98570B
+12v to pin1 or ground pin 3 to test.

Early Type 66232C needs 12v to pin 1 or 3 instead
(both blue capacitors touching type)

If disconnecting PCB:

UNPLUG 6 PIN FIRST THEN 2 PIN POWER PLUG

If reconnecting
REFIT POWER PLUG FIRST
6 PIN LAST

Jakg · 7th March 2016, 20:11

Quote:

Originally Posted by Union Wheels

Hi Jakg,
is it possible that the start up voltage to pin 1 of the 6 pin plug is intermittent or low.

I have read somewhere that the wiring between the alternator, temperature sensor and pin 1 of the heater can become corroded near to the temperature sensor plug.

Just an idea, Pete.

That certainly sounds possible - I've had wiring corrosion in that area before.

Do you have any more info on this please? Are you sure it's pin 6 on the earlier FBH? What voltage should I be expecting?

Jules · 7th March 2016, 20:19

Pete didn't say Pin 6 he said 6 pin plug !!!
I refer you to read my #218 again

Union Wheels · 7th March 2016, 20:20

Hi Jakg,

My post says pin 1 of the 6 pin plug.

This applies to both the early and later versions.

You are looking for 12volts.

Pete.

Jakg · 7th March 2016, 21:15

Quote:

Originally Posted by Jules

Pete didn't say Pin 6 he said 6 pin plug !!!
I refer you to read my #218 again

Quote:

Originally Posted by Union Wheels

Hi Jakg,

My post says pin 1 of the 6 pin plug.

This applies to both the early and later versions.

You are looking for 12volts.

Pete.

Sorry, long day - will check and update.

7th March 2016, 09:41	#215
Union Wheels Loves to post Honda Accord Tourer i dtec Join Date: Jul 2011 Location: Wakefield Posts: 331 Thanks: 56 Thanked 90 Times in 75 Posts	Hi Jakg, is it possible that the start up voltage to pin 1 of the 6 pin plug is intermittent or low. I have read somewhere that the wiring between the alternator, temperature sensor and pin 1 of the heater can become corroded near to the temperature sensor plug. Just an idea, Pete. __________________ [SIGPIC][/SIGPIC] How to Retrofit Diesel Cruise Control + Loom http://www.the75andztclub.co.uk/foru...87&postcount=1 How to Modify a 3 Speed Fan for CDT & V6 into a 2 Speed with a Resistor. http://www.the75andztclub.co.uk/foru...d.php?t=209920 CDT now gone to new owner, but still on forum

7th March 2016, 10:01	#216
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	FBH Golden rules recap Most common later type 98570B +12v to pin1 or ground pin 3 to test. Early Type 66232C needs 12v to pin 1 or 3 instead (both blue capacitors touching type) If disconnecting PCB: UNPLUG 6 PIN FIRST THEN 2 PIN POWER PLUG If reconnecting REFIT POWER PLUG FIRST 6 PIN LAST __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block

7th March 2016, 20:19	#218
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Pete didn't say Pin 6 he said 6 pin plug !!! I refer you to read my #218 again __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block

7th March 2016, 20:20	#219
Union Wheels Loves to post Honda Accord Tourer i dtec Join Date: Jul 2011 Location: Wakefield Posts: 331 Thanks: 56 Thanked 90 Times in 75 Posts	Hi Jakg, My post says pin 1 of the 6 pin plug. This applies to both the early and later versions. You are looking for 12volts. Pete. __________________ [SIGPIC][/SIGPIC] How to Retrofit Diesel Cruise Control + Loom http://www.the75andztclub.co.uk/foru...87&postcount=1 How to Modify a 3 Speed Fan for CDT & V6 into a 2 Speed with a Resistor. http://www.the75andztclub.co.uk/foru...d.php?t=209920 CDT now gone to new owner, but still on forum Last edited by Union Wheels; 7th March 2016 at 20:22..