M117 hot start

[Pullman]

Got a slight fault with my R107. Start's on the first turn of the key when cold but when she's hot seems a bit reluctant to start. I think it's fuel related. Bosch system. Cole has given me a couple of things to check out. All filters etc. have been replaced.

Dave

 

[robparker]

Not many people with that engine/Injection system any more.. what have you looked at so far then (and been advised to look at)?

 

[Pullman]

I haven't investigated the fault as yet. Not that annoying at the moment. Only done 16,000 miles and serviced regularly with no expense spared. Just researching to see if any body has experience with this fault. I have been told it could be faulty ECU. I have also been told it could be the injectors. Before I go down that route I want to make sure I have not over looked any simpler options to do with the amount of fuel delivered by the injectors. First thing I will probably do ( when she plays up ) is remove a spark plug and see if it's wet or dry. If it's wet then obviously it's over fueling ( flooding ). Other than that all I can think of is the SL shop!

 

[Richard Moakes]

If it's the K or KE injection, the injectors get worn out after about 75000 miles and will drip into the intake manifold when the car is shutdown. It can cause an overfuel situation which leads to difficult warm start and sometimes needing a 2nd attempt to start to clear out the excess fuel.

Had this on a W124 with M103 engine and KE injection, new injectors cured it completely.

 

[Pullman]

If it's the K or KE injection, the injectors get worn out after about 75000 miles and will drip into the intake manifold when the car is shutdown. It can cause an overfuel situation which leads to difficult warm start and sometimes needing a 2nd attempt to start to clear out the excess fuel.

Had this on a W124 with M103 engine and KE injection, new injectors cured it completely.

Thanks Richard.... very interesting...They are originals and therefore over 35 years old... that's two votes for injectors ....will bare that in mind.

 

[Cole@MBS]

Look up M and B fuels Dave, they supplied me with brand new Bosch injectors for my 124 at half the price!!! Glad Richard agrees with me on that, system is pretty good as a rule.......

 

[robparker]

Could also be worth replacing the fuel accumulator (by the fuel pump) which holds fuel pressure when you switch off.
I'm sure you will notice a big difference with new injectors anyway

 

[Pullman]

Richard

She can sit for weeks without starting the engine but always fires first time ( barely a revolution ). So I think it's holding pressure. Good point tho'.... Hadn't given that a thought.

 

[Pullman]

What is the consensus of opinion on injector cleaner as a intermediate diagnosis?

 

[Cole@MBS]

What is the consensus of opinion on injector cleaner as a intermediate diagnosis?

Not much!!!!!

 

[star]

Also check the one way valve in the end of the fuel pump, this can give you hot starting problems.

 

[Pullman]

........... right won't go there then.. Looked up M&B ... Eastleigh? ... Might pop round as well....... Cheers Cole

 

[Pullman]

Also check the one way valve in the end of the fuel pump, this can give you hot starting problems.

Thank you for that......would it be blocked or just letting fuel thro' ?

 

[LostKiwi]

It'll not be one way any more.....

 

[star]

Thank you for that......would it be blocked or just letting fuel thro' ?

It allows the pressure to drop.

 

[Pullman]

always get one don't we

 

[Pullman]

Spoke to Neil at M&B fuels..... agrees that it could be injectors......He suggests that they test them first ...... they collect and deliver as well ......... Brill.........Will be a job at end of season......... In the meantime if anybody can think something which might be relevant please get in touch ............ Thank you

Dave

 

[DREAMER NO2]

Yes i did find RED X was good in my tank . It could help keep the the injectors clean..
But if your engine as injector seals ,then they will need replacing at the same time as injectors. Thats if you go down that road.

 

[Richard Moakes]

Yes i did find RED X was good in my tank . It could help keep the the injectors clean..
But if your engine as injector seals ,then they will need replacing at the same time as injectors. Thats if you go down that road.

Agreed, the holders and seals perish, and would benefit from being replaced. The engine heat seems to turn them into Bakelite!

 

[Pullman]

Had the injectors tested and cleaned. Very professional service given by Mr Injector. During conversation with Steven Biggs he reported that the injectors were not leaking ( dribbling ). Given spec sheet on before and after testing. Refitted injectors with new MB seals and guides. Took for MOT ( passed ) but embarrassingly reluctant to start afterwards. Back to the drawing board.

Dave