The saga that is my 280
Discussion
Hi guys and gals,
OK, I've been having trouble with my 280 cutting out when warm, and then difficulty restarting, for some time now!
Had a fella round today to look at it 'cos I'd tried everything I could think of.
Anyway, after trying in vain to start it once it had cut out, the guy temporarily clamped the return fuel pipe to the tank and lo and behold, the damn thing started. His explanation was that the fuel pressure was too low. The clamping of the pipe caused the pressure to build up behind it and hey presto! That all seemed to make sense to me, but his recommendation was to replace the fuel pump.
Thing is, the engine keeps running fine if you rev it, it just won't tick over
I thought (perhaps wrongly) that if the fuel pump was faulty the pressure would remain the same irrespective of how much you rev the engine. If that is the case then the engine would run worse when revving not better, which leads me to be suspicious of his diagnosis.
Any views or possible alternative explanations would be greatly appreciated...
OK, I've been having trouble with my 280 cutting out when warm, and then difficulty restarting, for some time now!
Had a fella round today to look at it 'cos I'd tried everything I could think of.
Anyway, after trying in vain to start it once it had cut out, the guy temporarily clamped the return fuel pipe to the tank and lo and behold, the damn thing started. His explanation was that the fuel pressure was too low. The clamping of the pipe caused the pressure to build up behind it and hey presto! That all seemed to make sense to me, but his recommendation was to replace the fuel pump.
Thing is, the engine keeps running fine if you rev it, it just won't tick over
I thought (perhaps wrongly) that if the fuel pump was faulty the pressure would remain the same irrespective of how much you rev the engine. If that is the case then the engine would run worse when revving not better, which leads me to be suspicious of his diagnosis. Any views or possible alternative explanations would be greatly appreciated...
The fuel pump does deliver a constant pressure and flow rate (ok, might vary slightly according to voltage available as revs rise, but only a small amount). The fuel distributor incorporates a pressure regulator (basically a spring-loaded piston with shims to fine-tune the pressure) but this would hardly go out of adjustment by miles unless you fiddled with it.
The warm-up regulator is plumbed into the fuel distributor such that it modifies the pressure above the piston which rises with the flap meter; it reduces the pressure against the piston when cold so the fuelling can go rich during warm-up.
The fuel is 'leaked-off' past the pressure regulator so that anything above the required pressure (about 50 psi IIRC) is returned to the tank. Now it may be that the valve is stuck, returning all the fuel to the tank, which would give you insufficient pressure to start, and clamping the pipe would cure this BUT the system pressure would rise above the required level (depending on how fit your fuel pump is), i.e. it would potentially go hugely rich, but should allow the car to start as you describe.
Have you tried pulling the regulator out and cleaning it (it hides behind a big hex head on the side of the fuel distributor)?
A rare possibility is that the stainless steel diaphragm between the two halves of the fuel distributor has perforated.... but you don't want to pull that apart, oh no. Take it from me... ;-)
Ian
The warm-up regulator is plumbed into the fuel distributor such that it modifies the pressure above the piston which rises with the flap meter; it reduces the pressure against the piston when cold so the fuelling can go rich during warm-up.
The fuel is 'leaked-off' past the pressure regulator so that anything above the required pressure (about 50 psi IIRC) is returned to the tank. Now it may be that the valve is stuck, returning all the fuel to the tank, which would give you insufficient pressure to start, and clamping the pipe would cure this BUT the system pressure would rise above the required level (depending on how fit your fuel pump is), i.e. it would potentially go hugely rich, but should allow the car to start as you describe.
Have you tried pulling the regulator out and cleaning it (it hides behind a big hex head on the side of the fuel distributor)?
A rare possibility is that the stainless steel diaphragm between the two halves of the fuel distributor has perforated.... but you don't want to pull that apart, oh no. Take it from me... ;-)
Ian
Before replacing the fuel pump, I would have the output pressure checked. This is relatively simple for anyone who routinely services fuel injection systems as you can put a pressure guage where the fuel line enters the fuel distributor. My experience of fuel pumps (I've replaced 3 in 14 years of Tasmin ownership is that normally they just fail completely. I've only once had one deliver low pressure and then it was noticeable under acceleration when the engine would fade or when going uphill when it would fail to deliver sufficient pressure against the added gravity. In this case it was because the pump was partially blocked with the remains of the previous owner's incorrectly fitted fuel filter.
If you do have to replace the pump, Lucas have proved to be far cheaper than anyone else in my experience.
I'll be honest though, the symptoms you describe would make me start thinking about replacing the cold start valve on the back of the plenum chamber first.
Ralph Dodds
Tasmin Convertible & 350+2
If you do have to replace the pump, Lucas have proved to be far cheaper than anyone else in my experience.
I'll be honest though, the symptoms you describe would make me start thinking about replacing the cold start valve on the back of the plenum chamber first.
Ralph Dodds
Tasmin Convertible & 350+2
Ralph (THE Ralph Dodds I presume ;-) makes a good point - the only time I ever had a fuel pump fail on my Tasmin, it stopped dead after I hit a pothole deep enough to swallow a small country.
But I'd have my doubts about it being the cold start injector: unless it's very cold the Ford V6 is normally a good starter (I removed my CSI once when tryng to identify cause of rough running but the engine still fired up OK).
Ian
But I'd have my doubts about it being the cold start injector: unless it's very cold the Ford V6 is normally a good starter (I removed my CSI once when tryng to identify cause of rough running but the engine still fired up OK).
Ian
Thanks Guys!
Ian, I took the pressure regulator out today and all seemed to be in good order. I've taken the pump off (and in doing so snapped off one of the terminals - Bugger!). What Ralph says about engine fade is a symptom I experience, particularly when going up-hill. I don't think its the cold start valve either, 'cos it only happens when warm and I've disconnected the valve under these conditions to ensure that its not delivering excess fuel. No change though...
I've been quoted 130 odd quid for a new one from Fords (its a Bosch unit) does that seem about right??
How do you know which terminal is which, i.e. pos and neg? both the leads are yellow and there are no markings on the pump. Im guessing that getting them round the wrong way could be disasterous!!!
>> Edited by sjp76 on Sunday 2nd March 17:28
Ian, I took the pressure regulator out today and all seemed to be in good order. I've taken the pump off (and in doing so snapped off one of the terminals - Bugger!). What Ralph says about engine fade is a symptom I experience, particularly when going up-hill. I don't think its the cold start valve either, 'cos it only happens when warm and I've disconnected the valve under these conditions to ensure that its not delivering excess fuel. No change though...
I've been quoted 130 odd quid for a new one from Fords (its a Bosch unit) does that seem about right??
How do you know which terminal is which, i.e. pos and neg? both the leads are yellow and there are no markings on the pump. Im guessing that getting them round the wrong way could be disasterous!!!
>> Edited by sjp76 on Sunday 2nd March 17:28
It's a DC motor, so if you swapped the leads, the worst that should happen is it will run backwards, i.e. try to 'fill' the fuel tanks!
You should be able to simulate off the car: fill the inlet with petrol, apply 12V, see which way the fuel spurts!
Doubtless there'll be all sorts of dire warnings now from the doom-mongers about petrol, sparks etc. but what the hell: who wants to live forever? ;-)
Just don't do it near the car.
Donkeys' years ago, there were a very few instances of those sealed pumps igniting. The pump is a roller cell design with the motor totally immersed in petrol whilst it runs. Now as the brushes of a DC motor generally produce sparks as the commutator spins, you'd think that was a bad idea. But the ratio of fuel and air has to be right for it to ignite: this is also the reason why the hype about exploding petrol stations is largely unfounded. The amount of petrol you'd need in suspension in the air to cause a problem would be so high that people couldn't breathe, never mind light a fag... but I digress.
As there's no air in the car fuel pump, only petrol, no amount of sparks will ignite it. Apparently the ones that did go bang were either split or had air trapped in them, I forget.
As far as the actual problems with the car: er, dunno. It's a bit like being at work: I can only diagnose so much over the phone, after that I have to get in the van and go and fix it myself!
Ian
You should be able to simulate off the car: fill the inlet with petrol, apply 12V, see which way the fuel spurts!
Doubtless there'll be all sorts of dire warnings now from the doom-mongers about petrol, sparks etc. but what the hell: who wants to live forever? ;-)
Just don't do it near the car.
Donkeys' years ago, there were a very few instances of those sealed pumps igniting. The pump is a roller cell design with the motor totally immersed in petrol whilst it runs. Now as the brushes of a DC motor generally produce sparks as the commutator spins, you'd think that was a bad idea. But the ratio of fuel and air has to be right for it to ignite: this is also the reason why the hype about exploding petrol stations is largely unfounded. The amount of petrol you'd need in suspension in the air to cause a problem would be so high that people couldn't breathe, never mind light a fag... but I digress.
As there's no air in the car fuel pump, only petrol, no amount of sparks will ignite it. Apparently the ones that did go bang were either split or had air trapped in them, I forget.
As far as the actual problems with the car: er, dunno. It's a bit like being at work: I can only diagnose so much over the phone, after that I have to get in the van and go and fix it myself!
Ian
Got a bosch replacement pump from the local Bosch main agent yesterday for 70 quid (Bargain, considering Fords wanted 140). There seems to be some sort of non-return valve in the brass screw fitting that feeds the high pressure fuel pipe exiting the pump. Anyone ever had one of these go? It could explain the loss of pressure. Luckily the pump is identical to the one i've taken off so I know which wire goes where. Result!
Hi people,
I fitted the fuel pump last night, and it seems to be working fine, but I'm having real problems starting the car (Battery now flat!). Is it likely that there is air trapped in the system and, if so, does anyone know the best way to resolve the situation. Any other potential problems I'm overlooking?
Just to clarify, starting from cold was never a problem before!!
Cheers,
Steve.
I fitted the fuel pump last night, and it seems to be working fine, but I'm having real problems starting the car (Battery now flat!). Is it likely that there is air trapped in the system and, if so, does anyone know the best way to resolve the situation. Any other potential problems I'm overlooking?
Just to clarify, starting from cold was never a problem before!!
Cheers,
Steve.
Top man Ian!
I actually swapped the safety relay for a standard one to get the pump running and that did the trick!
Thing is, it STILL won't idle (Although its better than it was)??? Worth changing the accumulator?
I've already changed/checked just about everything else with the exception of the fuel distributor. Don't fancy playing about with that too much...
What d'ya reckon
I actually swapped the safety relay for a standard one to get the pump running and that did the trick!
Thing is, it STILL won't idle (Although its better than it was)??? Worth changing the accumulator?
I've already changed/checked just about everything else with the exception of the fuel distributor. Don't fancy playing about with that too much...
What d'ya reckon
You can test the fuel distributor as follows:
Pull all injectors and point them into glass jars, then hot wire the fuel pump (relay), and then lift the metering plate. All injectors should flow nice even mists of fuel a the same rate. If they don't try swapping the injectors - if the problem moves it's the injector - if it stay the same the fuel distributor is knackered. Don't bother trying to take it to bits if you intend use it again though!
The injectors should not flow/dribble when the metering plate is closed.
Danny
Pull all injectors and point them into glass jars, then hot wire the fuel pump (relay), and then lift the metering plate. All injectors should flow nice even mists of fuel a the same rate. If they don't try swapping the injectors - if the problem moves it's the injector - if it stay the same the fuel distributor is knackered. Don't bother trying to take it to bits if you intend use it again though!
The injectors should not flow/dribble when the metering plate is closed.
Danny
Cheers Danny,
Is there any way of checking that the air flow plate/plunger is connected properly or working correctly without taking the distributor to bits. I'm not sure what its supposed to feel like, but there is no friction there at all. I would have thought in moving the air flow metering plate, you would feel some sort of resistance as it operated the plunger within the distributor.
I'm thinking about getting someone (a bosch service agent) to look at it, but I wan't to avoid this for two reasons: 1, its likely to cost an arm and a leg and, 2, I don't like being beaten by something which is potentially quite trivial.
I had another go at spraying WD40 around pipe unions etc. but it made no difference, although the ineffectiveness of the idle screw still points to too much air!?! Its really starting to p*** me off!
Is there any way of checking that the air flow plate/plunger is connected properly or working correctly without taking the distributor to bits. I'm not sure what its supposed to feel like, but there is no friction there at all. I would have thought in moving the air flow metering plate, you would feel some sort of resistance as it operated the plunger within the distributor.
I'm thinking about getting someone (a bosch service agent) to look at it, but I wan't to avoid this for two reasons: 1, its likely to cost an arm and a leg and, 2, I don't like being beaten by something which is potentially quite trivial.
I had another go at spraying WD40 around pipe unions etc. but it made no difference, although the ineffectiveness of the idle screw still points to too much air!?! Its really starting to p*** me off!
You started off with a fuel pressure problem and it seems you may still have one.
The fuel pump was changed but that because you busted a peice off it, not because it was proved to be faulty. (there probably isn't a person on this board who hasn't f'd a part and had to change it)
The pressure plate is "damped" partly by fuel pressure. That could be the reason yours feels light. I would leave it alone for now!
I would really reccomend a pressure test.
The guage attaches to the warm up reg. Pressue is taken cold (no elec conn to WUR), hot, and a leak test.(10 min and 20 min)
The gauge is a ford tool. It is probably less than the cost of a test.
With regard to no adjustment on idle, that will prob be the Aux Air Device open when hot. That hole is ten times bigger than by-pass whole for idle adjustment, assuming you have checked for external air leaks.
If you fail the pressure test, look at the cheapest bits first, swirl pot and filtre. If you fail the leak test then look at accum first,"O" ring in pressure reg,cold start valve (for dripping) then internal leaks.
One test you could perform is fuel pump delivery, it should give 750cc in 30 secs minimum. It's a new pump but it would prove your flow is high enough to give the required pressure.
Do not be tempted to change the shims in the press reg just to get the req pressure, the fault has to found.
If you decide to do the P test yourself I can send the
pressure data. (and how to do it)
Jeff
The fuel pump was changed but that because you busted a peice off it, not because it was proved to be faulty. (there probably isn't a person on this board who hasn't f'd a part and had to change it)
The pressure plate is "damped" partly by fuel pressure. That could be the reason yours feels light. I would leave it alone for now!
I would really reccomend a pressure test.
The guage attaches to the warm up reg. Pressue is taken cold (no elec conn to WUR), hot, and a leak test.(10 min and 20 min)
The gauge is a ford tool. It is probably less than the cost of a test.
With regard to no adjustment on idle, that will prob be the Aux Air Device open when hot. That hole is ten times bigger than by-pass whole for idle adjustment, assuming you have checked for external air leaks.
If you fail the pressure test, look at the cheapest bits first, swirl pot and filtre. If you fail the leak test then look at accum first,"O" ring in pressure reg,cold start valve (for dripping) then internal leaks.
One test you could perform is fuel pump delivery, it should give 750cc in 30 secs minimum. It's a new pump but it would prove your flow is high enough to give the required pressure.
Do not be tempted to change the shims in the press reg just to get the req pressure, the fault has to found.
If you decide to do the P test yourself I can send the
pressure data. (and how to do it)
Jeff
I agree with Jeff M in principle. My hmm hmm 911 with a similar system definately has some resistance the first time I move the pressure plate, but once the fuel pressure is released is completely free. Beg, borrow, steal (even buy!) a pressure gauge. You might be able to find a pressure hose specialist who could knock something up for you for around £30.
Danny
Danny
Many thanks Danny/Jeff.
I would be greatful for any info re the pressure test Do it yourself way. For example, what should the Main and system pressures read (hot and cold).
Would it be reasonable to assume that if I took a 'main system pressure' reading at the entry to the distributor, that all components before it(i.e. swirl pot, pump and accumulator) are all OK??
Also I've found pressure test kit for about £50 quid (got quoted about that to have it done). My question is, are connections on the 280 of the 'Schroeder' type?? The kit I'm looking at has 8 and 10 mm shroeder connection adapters apparently. Will this do the job do you think?
Thanks again,
Steve.
>> Edited by sjp76 on Tuesday 11th March 09:28
I would be greatful for any info re the pressure test Do it yourself way. For example, what should the Main and system pressures read (hot and cold).
Would it be reasonable to assume that if I took a 'main system pressure' reading at the entry to the distributor, that all components before it(i.e. swirl pot, pump and accumulator) are all OK??
Also I've found pressure test kit for about £50 quid (got quoted about that to have it done). My question is, are connections on the 280 of the 'Schroeder' type?? The kit I'm looking at has 8 and 10 mm shroeder connection adapters apparently. Will this do the job do you think?
Thanks again,
Steve.
>> Edited by sjp76 on Tuesday 11th March 09:28
Steve
The ford pressure guage part no is 23-011
there are also pressure guage adapters part no 23-011-01
The ford guage has a shut off.
Cold control pressure at 16c should be .4 bar to .8 bar.
Control pressure warm 2.9 bar w/o vacuum
control pressure warm 3.6 bar with vacuum
System pressure 5.1 bar
Leak test
after 10 min 2.5 bar
after 20 min 2.0 bar ( I'm a psi person, 1 Bar = 14.5 psi)
I can e-mail you all the info on test, send me an e addy that I can send to.
Your assumptions re the proving the bits was good.
The shut off on the guage is needed to measure system pressure, the guage is between Fuel Dist and Wur so shutting it off gives full p reading. The shut off will also help you if you fail the time leak test, it can be closed and retested to determine which side of shut off has the leak
good luck
Jeff
The ford pressure guage part no is 23-011
there are also pressure guage adapters part no 23-011-01
The ford guage has a shut off.
Cold control pressure at 16c should be .4 bar to .8 bar.
Control pressure warm 2.9 bar w/o vacuum
control pressure warm 3.6 bar with vacuum
System pressure 5.1 bar
Leak test
after 10 min 2.5 bar
after 20 min 2.0 bar ( I'm a psi person, 1 Bar = 14.5 psi)
I can e-mail you all the info on test, send me an e addy that I can send to.
Your assumptions re the proving the bits was good.
The shut off on the guage is needed to measure system pressure, the guage is between Fuel Dist and Wur so shutting it off gives full p reading. The shut off will also help you if you fail the time leak test, it can be closed and retested to determine which side of shut off has the leak
good luck
Jeff
Gassing Station | Wedges | Top of Page | What's New | My Stuff