Doesn't Start When Engine is Hot

Thanks for the input. It's the wife's car. After a delicate detailed probing of facts (!), the actual events have been called into question. I, therefore, wait for it to happen to her again. Apparently, it has only happened twice. The glow plug indicator light is what I am not sure about. What definitely happened, though, was the inability for the engine to immediately restart after a short time period (about 1min) after a reasonable journey (about 30mins). She seems to think it did turn over when she tried to restart. Will post new info when it happens again. Thanks again.

Fuel filter changed only 6000 miles back, service is up to date as per Honda. No sign of battery or charging problem - car starts immediately (after glow plug lamp gone out) in recent sub-zero (celsius) temperatures of a morning. It's been a brilliant car but 12yrs old now. Sad when you think you won't get something that can replace it without increased maintenance charges down the line due to unnecessary increases in complexity (is it really so hard to use a key, for example; I'd much rather use a key and not get my car stolen).

Ok, experienced this first hand today. 30min journey, parked. 1min later tried to restart engine. Engine turned over fine but did not start. Glowplug lamp had not come on. Repeated a few times with same. 20mins later still the same; glowplug lamp still not lighting. Opened bonnet with aim of free air cooling down engine. 5mins later tried again, glowplug light came on for about half a second, engine started perfectly straight away after glowplug lamp went out. 30mins drive home. Turned off engine. Immediately tried to restart, glowplug lamp came on for a fraction of a second, engine started perfectly. Turned off and waited a few seconds. Tried again. Perfect again, glowplug lamp on for a fraction of a second, engine started perfectly.

I know what you are saying about this likely to be a combustion starvation problem but it could well be that this engine always needs a small kick from the glowplugs to start even when warm and that is no longer happening sometimes when the engine is warm for some reason. Battery seems fine. Fuel filter recently changed. No problems at all starting from cold. Feasibly, it might not be intermittent as I heard the fan come on after journey home while parking which may have caused the cooling needed just as before when I opened the bonnet, which is why I did not have the problem immediately after the journey home.

Adding all this mostly for recording the fault purposes. Will book in to Honda garage.

Louis Roscommon said:

I replyed to you and forgot to quote (if that helps) message above this......

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A low voltage battery shouldn't damage anything. I assume your replacement glow plug control relay was second hand? It could be that the replacement you got is faulty. I've been trying to find a schematic for it if only to be able to probe some connections but no luck so far.

My wife also supports the theory that this engine ALWAYS needs the glowplugs on for a bit before it will start, no matter how warm the engine. The controller is quite a complex beast and amongst other things, has two stage heating for the glowplugs. Initially it is very high current (I think this is when the dash lamp is on) then provides a lower current for 3 mins or so. I think I remember reading this.

The bad news is I found a report on a forum of someone pretty competent at DIY car issues who had the same problem with an Accord of the same vintage. After tracking through various relays they eventually said that they were told by a Honda garage that it may have a bad ECU, replaced the ECU with a second hand reprogrammed one and that fixed the problem. Whatever it is, it is clearly temperature related.

Does your immobiliser dash indicator (green key outline) flash when fault occurs, (with key in 2nd position and glowplug dash lamp not lit)?

Thanks very much for your update. Either the ECU is not communicating with the immobiliser hardware properly or the ECU key/immobilise check is failing internally. The fault is intermittent with likelihood increased with increased temperature or, feasibly, it is not temperature; it may be part of a circuit that is failing to fall/discharge to a reset state after the engine is turned off (or similar) due to a component failure. It could be something as simple as a dry solder joint (though this does not mean it is simple finding it) or something far more complex. There is a company in the UK that will 'rebuild' an ECU but no idea if they would be able to help as I have no experience of them:

www.ecutesting.com

They don't look like rip off merchants. They have a few youtube videos. I don't know my exact ECU model number but I can guess and it is not listed on their products page though 4 other apparently CRV models are. If it's a common fault then it might be worth their while establishing a fix. One tip I have read if you are doing this, disconnect the car battery and wait a minute before disconnecting the ECU (it's possible to cause more damage if power is applied to the ECU when disconnecting/reconnecting).

Louis Roscommon said:

Never again Honda - switching to Toyota. Thank You for info, I am going to scrap the car because they impossible to fix unless you know the right people or willing to gamble £100,000 + to get it fixed.

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I sympathise. Can I ask, how did you/Honda establish that the ECM/ECU was at fault or was this just a guess?

I am waiting for our car to get really bad before I start messing around with things that could render it inoperable. Current value is about £2k. We have spent £200 so far on two garages (one local, one Honda) failing completely to identify the problem. The Honda centre recommended we buy a new immobiliser ring (£300) but failed to diagnose that anything was wrong despite the fault occurring for the guy on the shop floor who we left it with, while we were there. We had been on a journey for 30mins or so, parked it at the Honda place, it didn't start for him but then it was let sit for hours until the mechanics got around to looking at it. They probably had it running with bonnet open and doors open, ticking over for 10mins, therefore exposing maximum coolness, and the fault did not re-occur, which it would not do if temperature related. I find it disgusting that they would then recommend we pay for a new immobiliser ring with absolutely no justification when that is only one element of a system including the ECM, immobiliser receiver unit, immobiliser ring (possibly contains receiver, not sure how 'ring' part is defined), multiplexer module, parking brake switch, fluid level switch, inertia/(+tilt?) switch, probably more, and all the wiring and connectors that go between.

If it is the ECM then this is made by Bosch whose ECMs are also sometimes used in Toyota. As Rocky says, I think peak value from the car industry for the consumer has now passed. Like many manufacturers of electronic goods, it is now all about making money in the short term. Models are changed so frequently that reliability cannot be assessed before a new model is produced. All consumer car manufacturers (same for most consumer electronics) now produce cars that, on average, will now have a practical operational life shorter than the previous model due to the nature of design of the electronic systems, the lack of adequately trained staff in service centres (mechanics rather than electronics technicians), the designed-in desire for the user not to do DIY, an inadequacy of self diagnostic systems and the inevitable proliferation of intermittent faults such as the one we are seeing here. The manufacturer wants to keep the product you paid for under their control, as well as wanting to know how you use it, and dictate to you how you should - we are effectively leasing more and more of our bought goods now without realising it. And, generally, people are so unwise that they think that having more 'features' is always a good thing.

The late great Douglas Adams identified the problem through his brilliantly comedic skill with the example of shoe shops on a planet where civilisation had died out because the economy had collapsed because everyone kept on having to buy more and more shoes because they were intentionally getting made worse and worse to make more money for the shoe manufacturing cartel. Later, archeologists examining the strata record found a thin layer consisting of compressed shoes. Anybody that survived evolved into birds and vowed never to set foot on the planet surface again.

Update. Bought second hand ECM off ebay (37820-RMA-E04 - £65). Removed cover using heatgun and sturdy flat blade screwdrivers as prizing tools, very carefully not to damage anything inside (patiently does it, applying heat and partially 'cracking' open one side at a time). This gave me the confidence to mess with the one in my car. Disconnected battery. Removed ECM/ECU from passenger footwell (37820-RMA-E06 - about 1yr younger than the ebay one I got) - only special tool needed was a deep 10mm socket. The connectors have a clever sliding catch at the end which, as you slide, push or pull the connector in or out of the receptacle. Desoldered ST M95320 EEPROM SOIC from both ECMs (this would not be trivial to anybody without electronics experience/tools). Put EEPROM from car ECM into second hand unit (after taking a memory dump as backup). Fitted second hand unit into car. Reconnected battery. Very pleased when car started straight away and everything appears to be running ok. Keep trying it when warm, keeps starting. Promising so far.

Note that this fault was temperature related but not engine temperature related. I assume it is the temperature of the ECM itself which is in the passenger footwell and this fault is something on the PCB or the connector to it. I would like to know what the fault is but I don't have the ECM schematic or even the wiring diagram to it and the PCB is heavily glued into the case. The fault could be anything from simply removing the ECM and refitting it (e.g. a connector contact, or even a power cycle (reboot)), a dry joint, or something more subtle like an ageing capacitor or other temperature dependant component in an oscillator circuit used in the comms between the immobiliser and the ECM, for example. Hope this helps someone else.