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Ok you obviously know best so carry on. With your vast experience and knowledge it amazes me you need to ask what is wrong with it.
M51 hot starting issues (don't shoot me ive searched until my eyes bled!)
- Thread starter simon allen
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Ok you obviously know best so carry on. With your vast experience and knowledge it amazes me you need to ask what is wrong with it.
simon allen
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Wammers - what side of the bed did you get out of this morning?
We've never met. You don't know my mechanical background. I was letting you know that I do have an internal understanding of these pumps. If that upsets you, I'm sorry.
I was asking if anyone had ever had the problem, and answering the questions brought up in response.
I've been out of forums for a while, surely we have got past the "lets assume the new guy's a retard" era? Maybe not?
We've never met. You don't know my mechanical background. I was letting you know that I do have an internal understanding of these pumps. If that upsets you, I'm sorry.
I was asking if anyone had ever had the problem, and answering the questions brought up in response.
I've been out of forums for a while, surely we have got past the "lets assume the new guy's a retard" era? Maybe not?
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You don't know mine either. You are not upsetting me. Nobody thinks you are a retard. It's just that i wonder why with your pronounced knowledge you don't know the answer to your problem. So how after all your buggering about with the pump and not knowing what has been done to it, do you expect anyone else to.
simon allen
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I don't specifically know your knowledge, but in all honesty you are the guy I was hoping to have spoken to after researching on google. Your name seems to pop up quite often. I am, however failing to see where I am asking anyone to diagnose a pump issue? I've told you that I've replaced the pump head as this seems to have been the "go to" solution for hot start issues throughout the cummins pages who seem to be the only ones out there rebuilding pumps themselves, but I've not asked a single question regarding my pump. I have, however asked about compression, and cam timing, and any other issues people may have had with these engines to cause hot start issues.
Have I worded myself badly?
Have I worded myself badly?
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If it has run and started cold and hot for two years, then all of a sudden will start cold but not start hot something has changed to cause that. If it has compression and it has fuel it should fire. If there is no compression even Easy start won't work as it cannot ignite. You may like to start with a compression test. Cold dry and wet then hot dry and wet see what you get.
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How much of your setup still has electronic control? Thinking crank sensor or similar that might be getting old and stop working when hot. Maybe with engine already running it is working on some default value?
When cold the fuel mapping will be different. So if not spinning over quite as fast as it should it might catch cold but not hot. More fuel when cold as well. Guess you could disable the stop solenoid briefly to rule that out. I'm guessing you know enough to get away with that.
Datatek
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With a mechanical FIP, the crank sensor is redundant.
Slow cranking can certainly cause failure to start.
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As is everything else sensor wise other than the engine temp sensor. A mechanical pump is a very inefficient way to run an M51. As far as i am aware the M51 never had a fully mechanical injection pump. It has always been EDC to my knowledge. .
Datatek
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Aye, it does seem a retrograde step. I have no idea if the M51 ever used a mechanical FIP, there was a VW 6 of similar capacity that was mechanical injection.
I was just about to suggest this, I had the same symptoms on a D1 I used to have in Portugal.
yes it sounds electrical , solenoid, relay,
simon allen
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compression tested ok, nice and even across the board and the same hot/cold as well. good call on the stop solenoid as well, I'll pull the plunger out and try it again.
If you don't like the fact that I have a mechanical pump on it, you certainly won't like that its in what's left of a disco 1 with bits cut off and bits welded on. Simplicity is key with what I do in it, not refinement - so the mech pump fits the bill perfectly (when it runs)
If you don't like the fact that I have a mechanical pump on it, you certainly won't like that its in what's left of a disco 1 with bits cut off and bits welded on. Simplicity is key with what I do in it, not refinement - so the mech pump fits the bill perfectly (when it runs)
Henry_b
Think outside, no box required.
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Love me old V8..
Just sayin'
Just sayin'
simon allen
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I love the noise and the instant grunt of the a v8 too
If I don't get to the bottom of this issue it will be getting pulled for either an m57, or a v8
If I don't get to the bottom of this issue it will be getting pulled for either an m57, or a v8
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You sound the sort of person who likes to make their life as difficult as possible. I have told you what to try and you totally ignore it.
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RangeRoller dt
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I have seen M51 mechanical FIPs in BMW cars. Even though I tend to dislike electronics I do actually prefer the P38 setup.
Does your Disco have a fuel pump supplying the FIP? Filling tank can help a little with this on times.
Have you checked your hotstart system is actually functioning?
Does your Disco have a fuel pump supplying the FIP? Filling tank can help a little with this on times.
Have you checked your hotstart system is actually functioning?
simon allen
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I haven't ignored anything, I've compression tested it. All 6 cylinders stable and with 10psi of each other at around 450psi from memory when cold and 430psi with the same varience when warm. Compression increased with oil in the bores which would tell me that the rings are ok.
Ive got a tank in the boot, it's about half full at the moment but it's been both full and empty since ive had the problem arise. I've got a facet pump feeding the injector pump, with a regulator set at 14psi - not sure if this is good for the m51 but it's what ive always run my bosch pumped stuff at before and had good success.It is still pumping, the gauge on the regulator is reading right even when warm.
Since I adjusted the cam timing to within spec (was slightly higher than the 4.5mm space I needed under the cam tool) the cold start has improved immensely. starts almost instantly which would tell me that the glow plugs are working at least? it used to crank for 3-5seconds before firing which I thought could have been the glow plug warming up time?
I'm going t0 try a genuine bosch stop solenoid next I think. What is the hot start system you're referring to Rangeroller?
Ive got a tank in the boot, it's about half full at the moment but it's been both full and empty since ive had the problem arise. I've got a facet pump feeding the injector pump, with a regulator set at 14psi - not sure if this is good for the m51 but it's what ive always run my bosch pumped stuff at before and had good success.It is still pumping, the gauge on the regulator is reading right even when warm.
Since I adjusted the cam timing to within spec (was slightly higher than the 4.5mm space I needed under the cam tool) the cold start has improved immensely. starts almost instantly which would tell me that the glow plugs are working at least? it used to crank for 3-5seconds before firing which I thought could have been the glow plug warming up time?
I'm going t0 try a genuine bosch stop solenoid next I think. What is the hot start system you're referring to Rangeroller?
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If compression increased with oil in the bores the rings are worn. If compression does not increase with oil in the bores the valves are worn. On the EDC version glow timing varies with engine temp. 4 or 5 seconds in summer up to 10 seconds in winter.
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RangeRoller dt
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Wonder if your edc is early setting?
V8, M57, genuine Bosch stop solenoid - you are a nutter
Early P38 M51 setups have an inherent ‘hotstart’ problem, which some clever members here worked a solution. Later models don’t have the issue ofcourse, I presume your M51 didn’t come out of a LR?
You need diagnostics, which unit I’m not sure?, or you’ll go round in circles bud. Stop solenoid can be tested I think - Datatek would know.
V8, M57, genuine Bosch stop solenoid - you are a nutter
Early P38 M51 setups have an inherent ‘hotstart’ problem, which some clever members here worked a solution. Later models don’t have the issue ofcourse, I presume your M51 didn’t come out of a LR?
You need diagnostics, which unit I’m not sure?, or you’ll go round in circles bud. Stop solenoid can be tested I think - Datatek would know.
