Looking for some help on this one as Diesels are a bit arcane to me.
I have a 1994 205 STDT [1.8 TD engine] which is is very good nick as it has been dry stored for the last 5 years and has just 65K on the clock. After pulling it out of the garage and cleaning it up, replacing the battery and putting some fuel in it, it ran great and sailed through its MOT.
However, after a few weeks it started to run a little roughly which I presumed was down to some crud in the fuel filter after it had stood for so long. Long story short, it turns out the fuel filter was clean as a whistle but there was a crack in the rubber fuel hose at the junction with this and the metal fuel pipe in the engine bay which was letting in air into the fuel system. I fixed this by cutting off the offending bit of rubber hose [only about 1"] and reconnecting the pipe and clamping it off with a jubilee clip.
Again it ran fine for a week or two but then started to present with starting problems, which were cured short term by using the priming button on the filter housing. However, this cure was short lived and it reached a point where it would not start at all.
I had the fuel tank checked for crud [due to the long layup] but this was all clear. The primer button on the filter seems to pull fuel through into the filter chamber but then it goes very hard to press and no amount of subsequent cranking will start the thing.
A pal reckoned it would start with a tow and he was right but it took about 3 miles before it would fire. It then drove fine until I got the thing home and parked it on my drive which is sloping. 2 hours later and no start....
A pal reckons the filter primer could be faulty and may be letting air in on the fuel pump side but I am not convinced even though he cites others who have had a similar problem, having solved it by replacing the primer pump.
Does the fuel system need bleeding after changing the fuel filter or should the primer button do this? Any ideas on what might be causing this starting problem? Should I prime the filter whilst turning it over to make sure there is no air in between the filter and the pump?
The car is in very good nick in most respects but I appreciate that standing for a long time will no doubt throw up a few little niggles but this one is stopping the car from being used which is a PITA.
Any suggestions would be most welcome.
Thanks
Blag.
1994 205 STDT Fuel issues
-
AndersDK
- Posts: 6060
- Joined: 21 Feb 2003, 04:56
- x 1
The prime button is there to to prime the fuel in case a leak is letting air in.
This leak may be anywhere in the fuel system.
I.e. most likely a rotten rubber hose which is brittle and has cracked.
A rust pinhole in the underbody fuel piping is likewise a wellknown issue.
The membrane in the primer button pump is also known to start leaking after years of service, in which case you will need a new filterhousing with primer pump, as no service parts are available separately.
I'd look for air leak problems as this is the most common diesel problem, and diesels are - hysteric - with air in the fuel lines.
Next most common issue would be the glowplugs. Those devices looking like spark plugs - but interlinked to the same low-voltage high Amperage cabling - coming from an electronic relay style plastic box. This heavy cable must be in good nick on all connections - including the battery cables going into the box.
The box will be your glow-plug timer relay, responsible for the finite time the glowplugs are connected initially on start - to preheat the cylinders for an easy engine start.
The glowplugs have a typical service life of some 60K miles (100K km), then they burn out - literally. They must be in good nick to give a sure engine start.
The plugs can be tested with an ohmmeter. Disconnect the heavy cable from the tip then read the ohms between the plug tip and any nearby engine earth. The rerading should equal or be less than 1 ohm - which is a shortcircuit in practical terms.
A much simple test is to use a High wattage (headlamp) bulb as a test lamp through the plug, as the low resistance (near-shortcircuit) on a sound plug should provide a good earth even for a high wattage bulb. The bulb should of course light up bright and clear - on each plug tested separately.
If the plugs seems to be disrupted on their tips - they are truly shot.
Not utterly expensive some £5'ish each.
Always replace as a full set of 4 like you would do spark plugs.
This leak may be anywhere in the fuel system.
I.e. most likely a rotten rubber hose which is brittle and has cracked.
A rust pinhole in the underbody fuel piping is likewise a wellknown issue.
The membrane in the primer button pump is also known to start leaking after years of service, in which case you will need a new filterhousing with primer pump, as no service parts are available separately.
I'd look for air leak problems as this is the most common diesel problem, and diesels are - hysteric - with air in the fuel lines.
Next most common issue would be the glowplugs. Those devices looking like spark plugs - but interlinked to the same low-voltage high Amperage cabling - coming from an electronic relay style plastic box. This heavy cable must be in good nick on all connections - including the battery cables going into the box.
The box will be your glow-plug timer relay, responsible for the finite time the glowplugs are connected initially on start - to preheat the cylinders for an easy engine start.
The glowplugs have a typical service life of some 60K miles (100K km), then they burn out - literally. They must be in good nick to give a sure engine start.
The plugs can be tested with an ohmmeter. Disconnect the heavy cable from the tip then read the ohms between the plug tip and any nearby engine earth. The rerading should equal or be less than 1 ohm - which is a shortcircuit in practical terms.
A much simple test is to use a High wattage (headlamp) bulb as a test lamp through the plug, as the low resistance (near-shortcircuit) on a sound plug should provide a good earth even for a high wattage bulb. The bulb should of course light up bright and clear - on each plug tested separately.
If the plugs seems to be disrupted on their tips - they are truly shot.
Not utterly expensive some £5'ish each.
Always replace as a full set of 4 like you would do spark plugs.
Anders (DK) - '90 BX16Image