I'm about to take on Rob's Tizzydee and I'll be puzzling out the cause of the problem so that i can sort it out before I go up to collect it. This will be the holding thread which explains my ideas as they occur to me. I'll be back when I've done some reading but it doesn't look too difficult so far.
We'll assume that the pump can provide enough power to lift the car because it will lift when the steering is turned and that the pinion valve is operational because turning the wheel has an effect. The fact that the steering is good suggests that the pump has some pressure and the fact that the stop light stays on points to an absence of pressure downstream of the FDV.
Things to rule out.
Lost ball from pressure regulator?
Faulty pressure regulator.
Determine what is going on in the FDV.
The mysterious FDV fault continued.
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- Citroen Sorceror
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2008 to 2023 - all sorts of stuff, some interesting
2024. TxD 1.9D estate. 'Wheelybin' - x 12
- ken newbold
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- docchevron
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- Citroen Sorceror
- Posts: 1266
- Joined: Fri May 20, 2005 8:51 pm
- Location: straddling the channel
- My Cars: 2003- Passe-Partout 1.9 TGD estate
2005 Grolliffe Tizzydee turbo estate and sundry other BXs and Grace, a CX TRD.
2008 to 2023 - all sorts of stuff, some interesting
2024. TxD 1.9D estate. 'Wheelybin' - x 12
Brain engaged, I think it looks like this: Pump feeds directly to FDV.
Pinion valve turns (or rotates, it is after all a matter of a pinion,) and cuts off the FDV. STOP light goes out eventually and car staggers to its knees.
There is a lot of pressure in the FDV because it is getting full pump pressure before it hits the PR and now it is cut off the flow (Which is minimal because one piston is STUCK) has nowhere else to go and heads for the suspension (at high pressure but very little flow). Once the system is pressurised, the normal leakage plus wear causes it to drop again because there is no adequate replenishment of the accumulator
BECAUSE NOTHING IS EVER GETTING TO THE PRV WHICH IS WHY IT NEVER TICKS!
The clue is in the cutting off of the flow when the pinion valve moves. The flow has to go somewhere.
I diagnose a stuck piston in the FDV and Green Globe Gang HQ (West) assures me that a replacement FDV is waiting for me to collect en route to a rescue mission abetted by my trusty partners in crime DLM and Grolliffe. It will be nice to get my hands dirty again. Watchmaking is very satisfying as a hobby, but sometimes you can't beat a cold day and an inert BX!
Pinion valve turns (or rotates, it is after all a matter of a pinion,) and cuts off the FDV. STOP light goes out eventually and car staggers to its knees.
There is a lot of pressure in the FDV because it is getting full pump pressure before it hits the PR and now it is cut off the flow (Which is minimal because one piston is STUCK) has nowhere else to go and heads for the suspension (at high pressure but very little flow). Once the system is pressurised, the normal leakage plus wear causes it to drop again because there is no adequate replenishment of the accumulator
BECAUSE NOTHING IS EVER GETTING TO THE PRV WHICH IS WHY IT NEVER TICKS!
The clue is in the cutting off of the flow when the pinion valve moves. The flow has to go somewhere.
I diagnose a stuck piston in the FDV and Green Globe Gang HQ (West) assures me that a replacement FDV is waiting for me to collect en route to a rescue mission abetted by my trusty partners in crime DLM and Grolliffe. It will be nice to get my hands dirty again. Watchmaking is very satisfying as a hobby, but sometimes you can't beat a cold day and an inert BX!
Last edited by tom on Sat Oct 25, 2008 3:27 pm, edited 2 times in total.
- Philip Chidlow
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These FDV's can be tricky and temperamental from my brief experience. I only had to swap out a HP pump for a better one to get issues with my FDV's calibration.
They seem to bed in with a known community..once one of the main components are changed then the FDV need recalibration. Also unless you really know what you are doing, an everyman overhaul is limited to seals and filters..do not attempt to touch the screw ring assembly...or kaos will ensue...
They seem to bed in with a known community..once one of the main components are changed then the FDV need recalibration. Also unless you really know what you are doing, an everyman overhaul is limited to seals and filters..do not attempt to touch the screw ring assembly...or kaos will ensue...
Current
85 BX GT Mk1..
86 BX TRS Mk1
87 BX TRi
Gone
85 BX TRS mk1 auto... SOLD
90 BX TRi..parts....cubed
85 BX GT Mk1..
86 BX TRS Mk1
87 BX TRi
Gone
85 BX TRS mk1 auto... SOLD
90 BX TRi..parts....cubed
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- Citroen Sorceror
- Posts: 1266
- Joined: Fri May 20, 2005 8:51 pm
- Location: straddling the channel
- My Cars: 2003- Passe-Partout 1.9 TGD estate
2005 Grolliffe Tizzydee turbo estate and sundry other BXs and Grace, a CX TRD.
2008 to 2023 - all sorts of stuff, some interesting
2024. TxD 1.9D estate. 'Wheelybin' - x 12
Still not entirely sure what it was - all I can assume was a stuck piston. However, the suspension now rises and the power steering works well.
Tom spotted a few probs, which I have decided to sort out, especially as I went on a high-speed run yesterday evening in the car and enjoyed it immeasurably!
R
Tom spotted a few probs, which I have decided to sort out, especially as I went on a high-speed run yesterday evening in the car and enjoyed it immeasurably!
R
- MULLEY
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1996 - AX Memphis 1.5D - Dream - SORN - x 8
Good news that you've managed to get your car working again, & well done to Tom for being a gent about it & for offering advice on other issues. Isnt this a cracking club....
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
I'm not just a username, i'm also called Matthew.
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
I'm not just a username, i'm also called Matthew.