Please can anybody help with this problem.
I have a 1996 ZX TD volcane which has just aquired a starting problem when cold.
This has just instantly happened, no gradual decreasing in starting performance.
Basicly the car takes about 5-10 mins to fire up when cold. The starter is winding the engine over fine, but there is only the occassional sound of it trying to fire.
There is electrical power from the glow plug relay to the glow plugs during the preheat period.
I have just changed the glow plugs, but when I took the old ones out they tested fine anyway.
Once the engine has run once, it then starts fine.
Any suggestions??
ZX TD volcane starting problem
Moderator: RichardW
Think about it logically.
The engine needs fuel, air and compression ( and a little heat if cold ).
To 'fire', the diesel / air mixute must be compressed until it self combusts.
Have you checked the cold start "waxstat" mechanism ? This may be the cause.
The worst case scenario is that you have low compression in one or more of the cylinders, but I would have thought something major like a blown gasket would cause that.
The engine needs fuel, air and compression ( and a little heat if cold ).
To 'fire', the diesel / air mixute must be compressed until it self combusts.
Have you checked the cold start "waxstat" mechanism ? This may be the cause.
The worst case scenario is that you have low compression in one or more of the cylinders, but I would have thought something major like a blown gasket would cause that.
Thanks
I've checked the fast idle thermostat and it seems to be working fine. The cable's nice and tight when cold, with the lever fully to the right. When the engine heats up the cable extends slackening off the lever.
I don't think it's a head gasket problem.
The car idles fine and has no problems throughout it's whole rev range with no power loss felt. There is no coolant loss, or oil in the coolant or visa versa.
The only problem is when it is cold i.e. left overnight - Thats when it doesn't want to play. Other than that she starts fine.
I've checked the fast idle thermostat and it seems to be working fine. The cable's nice and tight when cold, with the lever fully to the right. When the engine heats up the cable extends slackening off the lever.
I don't think it's a head gasket problem.
The car idles fine and has no problems throughout it's whole rev range with no power loss felt. There is no coolant loss, or oil in the coolant or visa versa.
The only problem is when it is cold i.e. left overnight - Thats when it doesn't want to play. Other than that she starts fine.
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pete woods
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Dave Burns
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Look for an air leak in the fuel return piping, most common is the injector leakoff pipes and the blanking cap on No.1 injector (flywheel end), its usually nothing more serious than that.
A leak in the return line allows air to be drawn in and the fuel in the supply line to drain back to the tank, it also syphons the fuel out of the injection pump over a long enough period of time, resulting in complete refusal to start.
Iv'e only ever known this type of behaviour on the XUD with the Bosch pump and its very common, the Lucas pump does not appear to suffer from this problem because the stop solenoid cuts of the incoming supply of fuel to the pump, also meaning it can't then be syphoned back with the engine off if an air leak occurs.
The stop solenoid on the Bosch pump cuts of fuel to the high pressure stage within the pump, so with the engine switched off there is nothing to prevent the movement of fuel through the pump should an air leak develop.
A leak in the the supply line will allow fuel to run back to the tank through the return line, air will be drawn in and naturaly makes its way to the pump, on this occasion however the pump does not get syphoned dry, because as air comes in through the lift pump it rises through the fuel in the pump body and gets out through the oulet restrictor at the top of the pump.
When an engine is started in this state (doesn't need the lift pump to start), it runs for an extremely short period before missfiring badly or even stopping altogether, the reason is the lift pump has air in it and the pipe leading to it has air in it, and so air enters the pump in volume soon after starting, this swirls about in the fuel inside the pump due to the rotating components, and some of it gets drawn into the high pressure chamber where it compresses causing missfiring and late injection, if the engine doesn't stop it carries on missfiring until the lift pump is once again delivering fuel and any air is expelled through the restrictor into the return line.
Do as Pete says and pump the hand primer until it goes firm, this will fill the injection pump with fuel, look at the leakoff pipes as you pump, often any that leak will give themselves away.
Don't crank the engine for long periods, even if the battery is up to it, death of the starter motor wont be far away.
Dave
Edited by - Dave Burns on 02 Feb 2003 21:15:50
A leak in the return line allows air to be drawn in and the fuel in the supply line to drain back to the tank, it also syphons the fuel out of the injection pump over a long enough period of time, resulting in complete refusal to start.
Iv'e only ever known this type of behaviour on the XUD with the Bosch pump and its very common, the Lucas pump does not appear to suffer from this problem because the stop solenoid cuts of the incoming supply of fuel to the pump, also meaning it can't then be syphoned back with the engine off if an air leak occurs.
The stop solenoid on the Bosch pump cuts of fuel to the high pressure stage within the pump, so with the engine switched off there is nothing to prevent the movement of fuel through the pump should an air leak develop.
A leak in the the supply line will allow fuel to run back to the tank through the return line, air will be drawn in and naturaly makes its way to the pump, on this occasion however the pump does not get syphoned dry, because as air comes in through the lift pump it rises through the fuel in the pump body and gets out through the oulet restrictor at the top of the pump.
When an engine is started in this state (doesn't need the lift pump to start), it runs for an extremely short period before missfiring badly or even stopping altogether, the reason is the lift pump has air in it and the pipe leading to it has air in it, and so air enters the pump in volume soon after starting, this swirls about in the fuel inside the pump due to the rotating components, and some of it gets drawn into the high pressure chamber where it compresses causing missfiring and late injection, if the engine doesn't stop it carries on missfiring until the lift pump is once again delivering fuel and any air is expelled through the restrictor into the return line.
Do as Pete says and pump the hand primer until it goes firm, this will fill the injection pump with fuel, look at the leakoff pipes as you pump, often any that leak will give themselves away.
Don't crank the engine for long periods, even if the battery is up to it, death of the starter motor wont be far away.
Dave
Edited by - Dave Burns on 02 Feb 2003 21:15:50
Hi thanks for the replies.
The bleed lines and end cap have recently been changed - ther are no visible signs of leaking.
The pump is a lucas, and when it first failed to start my first instinct was to reprime the system. But to no avail.
I'll have another inspection of the pipes, buts I've spent all day checking and rechecking things.
When it fires up it runs fine no choughing or spluttering. It has all the symptons of failed glow plugs. My wifes car had 2 go and it spluttered to start. This feels like the whole lot are not working. But I've checked the feed and I'm getting the 12v during preheat. The glows have been changed for new, and checked before fitting. ( the old one were checked when they came out and were okay)
I rechecked the waxstat and its fine.
My gut instinct says electrical, but like you I've checked the fuel side as well.
I've even wound it over with the immobilser on,( just in case it's playing up) but its a totally different sound.
I've just diven 250 miles in it this afternoon, and there's nothing noticeably different.
The one thing I did notice was the pipe going from the intercooler to the pump is slightly perished ( I'm not sure what this is for).
Thanks again for the replies. Hopefully something will come to light.
I'll keep you posted on the outcome - if I can find it.
The bleed lines and end cap have recently been changed - ther are no visible signs of leaking.
The pump is a lucas, and when it first failed to start my first instinct was to reprime the system. But to no avail.
I'll have another inspection of the pipes, buts I've spent all day checking and rechecking things.
When it fires up it runs fine no choughing or spluttering. It has all the symptons of failed glow plugs. My wifes car had 2 go and it spluttered to start. This feels like the whole lot are not working. But I've checked the feed and I'm getting the 12v during preheat. The glows have been changed for new, and checked before fitting. ( the old one were checked when they came out and were okay)
I rechecked the waxstat and its fine.
My gut instinct says electrical, but like you I've checked the fuel side as well.
I've even wound it over with the immobilser on,( just in case it's playing up) but its a totally different sound.
I've just diven 250 miles in it this afternoon, and there's nothing noticeably different.
The one thing I did notice was the pipe going from the intercooler to the pump is slightly perished ( I'm not sure what this is for).
Thanks again for the replies. Hopefully something will come to light.
I'll keep you posted on the outcome - if I can find it.
Firstly the small pipe from the intercooler feeds the extra fuel device on the pump and the turbo boos warning light. If it fails the car will run normally at low revs but simply will not receive any extra fuel when the turbo is running.
Is your stop solenoid working correctly? It can be tested by unscrewing it and removing the operating spring and then replacing it. If it is faulty the engine will now start and you will have to stop it using the lever on the pump marked stop. New ones are I believe about £20 from some accessory shops.
Jeremy
Is your stop solenoid working correctly? It can be tested by unscrewing it and removing the operating spring and then replacing it. If it is faulty the engine will now start and you will have to stop it using the lever on the pump marked stop. New ones are I believe about £20 from some accessory shops.
Jeremy
Hi thanks for the info.
The stop solenod is working fine.
The problem is baffling me now.
When I started the car this morning it started up on the first turn of the starter motor. With the fault no where to be seen.
I don't know whether the weather we've had over the weekend has had anything to do with it, as it was extremely cold ( having said that it's never caused a problem before, and the cars garaged)
I don't know whether the faults cured, or will come back.
It could have been sorted out when I changed the glows, and sprayed up all the preheat relay, or there may have been an air gap on the injector bleed hoses which closed up as the were checked for security and integrity.
I'll check it tomorrow morning and see where we stand, hopefully the pixies will have worked their magic and it'll be okay.
Thanks again evryone for you help.
The stop solenod is working fine.
The problem is baffling me now.
When I started the car this morning it started up on the first turn of the starter motor. With the fault no where to be seen.
I don't know whether the weather we've had over the weekend has had anything to do with it, as it was extremely cold ( having said that it's never caused a problem before, and the cars garaged)
I don't know whether the faults cured, or will come back.
It could have been sorted out when I changed the glows, and sprayed up all the preheat relay, or there may have been an air gap on the injector bleed hoses which closed up as the were checked for security and integrity.
I'll check it tomorrow morning and see where we stand, hopefully the pixies will have worked their magic and it'll be okay.
Thanks again evryone for you help.
It sounds if you have an intermittent fault with the Heater plug relay, not always energising the heaters. I changed mine sometime ago, because it had a tendency to stay on for long periods. When I changed it and had a look inside there was corrosion on some of the soldered joints of the electronics. I found this fault by rigging a 12v bulb of about 5watts to the heater plug wiring connection and trailed it inside the car temporarily to watch if it stayed on or not. Normally it stays on for approx. 2mins, mine was staying on for 15mins. Although you have a light on the dash, its not directly connected to the heater circuit, giving a false reading whether its on or off.
Worth a try. Or you may have temporarily cleared an electronic fault by dispersing moisture with the spray up you did ???
Good Luck
Sooty
Sooty
Worth a try. Or you may have temporarily cleared an electronic fault by dispersing moisture with the spray up you did ???
Good Luck
Sooty
Sooty