P38A Engine turns over but not starting

DanClarke said:

When it turns over while just cranking do you see anything on the Rev counter?
If you recently had the Crank Sensor replaced for a very good reason I would suspect the new one and/or its wiring.
Not sure why having diags attached makes any difference, but clearly it does in some strange way.

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I did not notice the rev counter, I will have a go & look at it tonight. It did show 750rpm on the snap on diag.
Are you saying that if the Crank Sensor is faulty there will be nothing showing on the dash Rev counter?

Hi Storm,
I really don't know mate .... but!
A you tube search on a V8 Rover starting issue came up with that as a tell-tale sign on a starting issue, and you have recently had it changed I thought?

The only other suggestion is to not take a scattergun approach you've found the problem ok now find the cause. If it ran ok when your obd was attached can you reproduce this everytime. Is it running perfectly when it's attached ie would you drive 50 miles with this attached confidently?
These are not that complicated and something has blown that track which is not the ground multi sensor.

I think that you are trying to access a locked becm. This is not right you need to go to the gems engine ecu section not the becm. Then go to the utility section then to security learn. This is never locked only the becm can be locked and access to this is not needed.
Jb

storm said:

a friend came round with a Snap on Diagnostics machine last night. With the original engine ecu connected & with the diagnostics reading the engine details she started !! & run smoothly with no black exhaust.
But once the machine was disconnected it would not start just cranked over. Tried the replacement engine ecu & the Snap on machine connected, dash lights came up, then nothing when turning the key.

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Snap-on, not Nanocom. No idea about Snap-On. @biketeacherdave might have played with it?

I think without diag that at least one of understands we're chucking dice.

U may not be able to learn code on that snap on diag

Well, until someone with a P38 GEMS specific nanocom pops their head over the parapet we are a bit sunk.

One post says pete12345 very kindly popped over with his nanocom I think but found that the ecu was locked. I think he was accessing the wrong nanocom menu. He was trying to access the becm which are often locked. Instead of the engine ecu(gems) utility section security learn. Even this has a procedure. This is always straightforward tbh.key to pos 2 press security learn turn off then back on to ignition.starts.

I get my Nanocom on Friday, its no use to Storm as mine is for my Bosch Motronic although I am relatively local to him.
The code & cable for a GEMS is not cheap as an add-on either. I have never played with a Nanocom and am terrified of breaking the frigging thing on my first go. LOL

I would also suggest from that description she started and run smoothly the bridge wire must have worked. Without the bridge working it could never have worked properly past black smoke difficult start etc so working when the snap on is plugged in is just a freak side effect of 1. Another issue 2. The cause of the issue originally not yet been addressed. 3. And chance and an intermittent fault but a fixed ecu allowing normal running briefly. Bear in mind even with an intermittent fault it could never have run properly prior to the bridge.
That burnt tracks purpose holds the key.

Yer I tried to do it for him but I've only got the mototronic module on my nanocom

Don't worry about the nanocom breaking there pretty foolproof. I remember the initial signing in was a bit daunting but in use it's great. I guess the slight clunkiness( in Iphone terms) is the ecus of the mid 90s and not the nano!

DanClarke said:

I get my Nanocom on Friday, its no use to Storm as mine is for my Bosch Motronic although I am relatively local to him.
The code & cable for a GEMS is not cheap as an add-on either. I have never played with a Nanocom and am terrified of breaking the frigging thing on my first go. LOL

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You only need the GEMS module which costs about £50 extra. Cable is the same. I have diesel and GEMS on mine.

From the Nanocom manual for the GEMS module:

Security learn mode: When the ignition is turned on, the BECM, providing it is in receipt
of a valid mobilization code and is therefore not in an alarmed or immobilised state, sends
a coded signal to the GEMS which the Gems then compares against a mobilization code it
has stored in it. If the two codes compare OK, the Gems will allow the engine to start. This
forms the basis of the immobiliser. If the GEMS ECU, the BECM, or the lockset & key fob
is replaced or other data in the BECM is changed, it may be required for the GEMS to
re-learn a new mobilization code. This is done by using this function to put the GEMS into
Security learn mode whereby the next coded signal it receives is not compared but is
instead stored as the master copy. When security learn mode has been entered the ignition
must be turned off and turned back on to trigger the BECM into sending the code. The
GEMS will check the incoming code and should accept it; however, if there is an error no
matter how slight in the codes makeup, the GEMS can reject it, in which case there will be
no valid code stored. This situation can be checked by looking at the security learn status
in Inputs - Engine and Other which denotes whether the system has a valid code stored or
not.

Hi Guys, sorry I've been away with work, & will get back to the car at the weekend.
I not 100% that my solder of the bridge wire is making good contact, so will re check that.
Its annoying that the replacement ecu does do anything when turning the key as I can not see any burnt tracks in it.
I will try re entering the EKA code to see if that does anything, but it sounds like a sync mate is needed.
Again thanks for all help & suggestions.

U need sync mate or gems on nanocom I can get it but it's 55 quid hope u can find someone local there must b someone out there local

I've got a GEMS syncmate that I hire out - but a couple of things to check first.

You say when you plug the other engine ECU in, the dash lights go out when you go to crank, but nothing happens. 1) Does the orange 'Check engine' light go out with the key in position II and the replacement ECU fitted. If not, then it is a security sync issue (at least) and the Syncmate should sort that out 2) with the replacement ECU, does it actually turn over, or do you get absolutely nothing?

It's a pity I'm not closer aswell, as I have a Nanocom which is unlocked for all P38's!

Storm,
You got this sorted yet, its all gone a bit quiet?
Hoping you have and she's up and running again.

Definitely interested in any outcomes storm!