Discovery 300TDI cranks but won’t start

Hi guys,


I have a 1995 Discovery 300TDI, automatic with the EDC diesel pump.


A few weeks back, after having been parked up for around a month it began having intermittent starting issues.


It would happily crank but not fire. Usually turning the key completely off then back on again once or twice would fix this and it would fire up and be perfectly fine. It could go several days at a time without this repeating, or it could happen multiple times a day.


There was one instance where it took 10-15 repetitions of turning the key off and back to cranking for it to start, although it then spent the next week with just one repeat where I had to cycle the key to get it to start.


This brings me to last Friday when after having driven it on a couple of small trips around town with no issues it then refused to start. No matter how many attempts at cycling the key I tried, still no firing. I even managed to flatten the battery and had to swap in a good one but still no luck.


Does anyone know what may be responsible for this, or what I should be checking or testing? Any input or ideas would be greatly appreciated


Cheers,


James

A couple of other observations to add:

1) the fuel pump no longer buzzes with the key in the run position as it used to. I’m not sure if I’m the previous instances where it wouldn’t start that the buzzing was absent though

2) Potentially unrelated, but when I put the key in the run position it activates the air conditioning pulley solenoid. Potentially related to an ECM issue as it’s powered through the ECM or is this normal?

And 3) While it was playing up I would occasionally try revving the engine and quickly cycling the key off then back on. Usually the engine would just keep running when the key was back on as the revs hadn’t fallen far. But on occasion it would just stall requiring me to cycle the key to get it going again. So even if the engine was turning over at 1500+rpm if it were turned off and on quickly it would stall

could it be a sticky stop solenoid on the injector system?
Don't have an EDC so just putting this out there.

Stanleysteamer said:

could it be a sticky stop solenoid on the injector system?
Don't have an EDC so just putting this out there.

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As of a few minutes ago the truck has started again. I wish I could be completely confident about what I did or what changed before it started but I think you could be right, as I did move the wires around the cut off solenoid soon before the pump started buzzing again and the truck started. It briefly refused to start again after a quick drive, but this time it started without cycling the key all the way off then back on so I assume the fact it had started before only after being cycled was a fluke.

Could anyone familiar with EDC tell me, would the solenoid sticking also cause whatever it is that buzzes in the pump not to buzz?

My own D1 was built with EDC - lack of spare parts meant it was taken off - substituted for a fully mechanical FIP, without electronic "stuff" - I have thus purposely forgotten more or less everything I had learnt about the EDC system ..

IIRC, RAVE has a good description of the system, and decent circuit diagrams too - though, being as they are spread about over a few pages - they can be a bit awkward to follow - I printed the relevant pages out, and taped them all together when I was faffing with mine.

Whilst intermittent faults of this nature can be a royal PITA to trace... I suggest a thorough test of all powers and grounds to the FIP - IMO said tests need to be load tests too - NOT simple DMM voltage tests .. I.E. will the circuit light a lamp of appropriate current draw ?

The buzzing in/from the FIP is, IIRC, the quantity servo - they get noisier as they get older ( normal ish ), and often noisy with air in the fuel.. so this might be worth checking too.

Apart from parts NLA, it is quite a decent well made system, so I suggest a faulty connection in the FIP multiplug is likely..

Treat #4 injector as if it is made of unobtanium - because it is!

JimmyOlds said:

Could anyone familiar with EDC tell me, would the solenoid sticking also cause whatever it is that buzzes in the pump not to buzz?

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I wonder if the solenoid not working ( maybe due lack power or ground or internal fault ) is monitored by the EDC ECU - and if therefore - no continuity through the solenoid means the ECU won't turn the FIP "on", as it were ?

IIRC, the diagnostics I bought for mine ( hawkeye ) were pretty poor, and functionally very restricted.. Don't know if other diagnostics are better..

It also occurs to me that if cycling the ignition switch rapidly "makes" it work, if this is something as simple as a duff ignition switch...?

Personally, I'd avoid rapid cycling of the sw - I don't the EDC ECU is going to "like" repeated cycling very much..

On the edc the stop solenoid is superfluous. I had a similar intermittent fault and was advised to remove the innards of the stop solenoid. Didn't solve my problem but I never replaced the parts, engine still stopped normally. I never got to the bottom of my woes, use the vehicle for a few hours and suddenly it would spin over but not start. When I cracked open the pipes at the injectors there was no fuel. If I gave it a few days, started normally. You could open up one injector pipe next time it wont start but I've no solution other than a suspect green ecu in the passenger footwell (as I was advised)

Hmm based on my readings about the system and it’s parts and diagnostic availability I think I might just take the easy route and replace it with a mechanical fuel pump! Really wishing right now it had just come mechanical from the factory. The headaches it causes are not worth the alleged ~10hp gain, especially if this had happened while I was on a big trip!

JimmyOlds said:

I think I might just take the easy route and replace it with a mechanical fuel pump!

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You'll need injectors too - the ones fitted to the EDC are a significantly higher pressure than the "normal" VE FIP spec..

If you fit the larger VE pump, and and FWIC, AND get it tuned properly, then you can get about 164HP out of the engine* - BUT, the intake roar is somewhat annoying. ( ask me how I know )... 150 HP is safer for EGT's, and quieter to boot ( you can ask me how I know this too )..

If you want the engine to last , fit an EGT gauge - in fact, IMHO it's more important than the rest of it.. EGT's climb rapidy, and they will anneal the CH = no engine

* = the 300Tdi can be tuned to about 200 HP before it will die horribly, BUT EGT's and the cooling system are the weak links, and have to rigorously monitored and rigorously maintained - All in all, it is probably easier, and probably cheaper to fit a V8.

The 300 edc chipped is a proper flying machine.