Warm starting problem on M51 Diesel

[iainand]

hey guys, hope someone can help with a few pointers here.

my 525 tds is a nightmare to start once warmed up.
starts great cold, a flick of the key has her running.
any time i try to start car, if the car is cold enough for the glowplug light to come on the car will start straight away. If on the other hand the engine is warm enough for the glowplug light not to come on, the key will have to be held in start position for up to 30 seconds to start.

i have ran car until engine is slightly warmed up, turn off, turn on ignition again, if glowplug light doesnt come on, same problem, poor starting.

switch off leave a minute, turn on ignition again, glowplug light comes on, engine starts straight away!!!

normally if engine is fully warmed up and you switch off for a minute, restarting can take a lot of cranking again.

I think once the car is warm enough not to require glowplugs to start, the intank fuel pump is not running. something is not telling it to run. could this be the problem???

ran 'stomp test' only fault that comes up is '29 - speed signal' managed to cure previous code 'start of injection'.

HEEEEEEEEEEEEEEEEEEEEEEELP

this is driving me crazy!

[Sailor]

Sorry don't know your specific Injector pump, but I do know diesels. That really sounds like an injector pump problem. When the pump is warm and the fuel is thin the proper pressure does not build for good atomization. Low rpm can also hurt if the pump is marginal. Speeding up the starting rotation IE good battery and starter?A couple of tests can be done but they may not work as they are dependant on design. Sometimes jumping the glows so you heat the glows even though the motor is warm will fire the engine quicker. If that works a suplimental manual glow switch can be used. But...... you still should get a rebuild. Seems like you have sort of done this test. Your results warrant spending the bucks for a diesel doctor to look at it, you know a "pump" guy. Another test is to cool the pump. On a truck you would pour luke warm water on it. If it fired you would know the pump is warn. This is a DANGEROUS TEST!! Some types of pumps may not be able to cool that fast and break as a result. Bottom line I would see a pump guy for this because diagnosing a bad pump takes special tools and know how. You can try opening the hood for 10 minutes and putting a fan on the Injection pump.If that also makes it fire right away go see a pump guy, you need his help.