P38A Non starting diesel

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
B

Bribull

Member
Posts
16
Location
Melksham, Wiltshire
Hi all, I'm trying to run a 1996 manual p38 diesel as a stand-alone engine. There is a label attached to the ecu to say it has the immobiliser bypassed. There is power to the solenoid, and diesel to the fip, but no diesel from the injector pipes while cranking.
I'm running the original in tank fuel pump. Am I wrong to assume because the immobiliser has been bypassed it has no need of the becm, or am I missing something.
I seem to remember reading somewhere the diesel ecu does not get a coded signal from the becm to run like the petrol, rather a steady voltage ( 5 volts ?,12 v olts? ) . A bit reluctant to try this in case it causes some damage.
Any help or suggestions will be greatly appreciated, Thank you.
 
Bribull said:
Hi all, I'm trying to run a 1996 manual p38 diesel as a stand-alone engine. There is a label attached to the ecu to say it has the immobiliser bypassed. There is power to the solenoid, and diesel to the fip, but no diesel from the injector pipes while cranking.
I'm running the original in tank fuel pump. Am I wrong to assume because the immobiliser has been bypassed it has no need of the becm, or am I missing something.
I seem to remember reading somewhere the diesel ecu does not get a coded signal from the becm to run like the petrol, rather a steady voltage ( 5 volts ?,12 v olts? ) . A bit reluctant to try this in case it causes some damage.
Any help or suggestions will be greatly appreciated, Thank you.
Click to expand...

I think it changes with the year. One had a solid or initial signal and one had a repeating signal. If they've replaced the chip then it may not need tha code.

Stop solenoid is the other thing worth checking.
 
Grrrrrr said:
I think it changes with the year. One had a solid or initial signal and one had a repeating signal. If they've replaced the chip then it may not need tha code.

Stop solenoid is the other thing worth checking.
Click to expand...
They all need a code, no exceptions apart from a brand new EDC which comes in non secure mode and can optionally be changed to secure mode which is always done in the case of the P38.
 
Datatek said:
They all need a code, no exceptions apart from a brand new EDC which comes in non secure mode and can optionally be changed to secure mode which is always done in the case of the P38.
Click to expand...

They can have the immobilizing function removed to run "standalone" for both petrol and diesel.

How I dont know.

J
 
marjon said:
They can have the immobilizing function removed to run "standalone" for both petrol and diesel.

How I dont know.

J
Click to expand...

On the diesel the chip needs to be left at non-secure so only with a new chip - hence my comment. The chip can only be written once although a polish guy I spoke to once reckoned you could overwrite by doing something weird like zapping it with UV light reflected off a unicorn horn but that's beyond my ken so I put it down as unproven rumour.
 
marjon said:
They can have the immobilizing function removed to run "standalone" for both petrol and diesel.

How I dont know.

J
Click to expand...
I have no idea about petrol versions but on the diesel the code is written into non re-writable memory, once the secure flag is set, the only way round that is to produce the code using an Arduino or such like, or if you are really clever a piggy back chip that will transmit the code. If there are other ways, I have never heard of them which doesn't mean they do not exist of course.
 
That's true, but it looks official. I've opened up the ecu, and it has been chipped by superchips.
The car originally went to a garage to have a head gasket done and it's not run since.
 
Bribull said:
That's true, but it looks official. I've opened up the ecu, and it has been chipped by superchips.
The car originally went to a garage to have a head gasket done and it's not run since.
Click to expand...
Is that with a piggy back chip? If so they may have overridden the immobiliser one way or another.
If the head gasket has been done, I wonder if they have got the FIP & cam timing correct?
 
No the chip is not piggy backed, it's a replacement chip. Its true they may have the fip and cam timing wrong yet, but would that stop the fip pumping diesel to the injectors, albeit at the wrong time.
 
Bribull said:
No the chip is not piggy backed, it's a replacement chip. Its true they may have the fip and cam timing wrong yet, but would that stop the fip pumping diesel to the injectors, albeit at the wrong time.
Click to expand...
If the chip has been replaced then it is certainly possible that there is no mobilisation code required.
I don't know all the detail but there are things like the crank sensor that are involved in injector timing. If the timing is way out it may well be the the EDC will not permit injection but I really do not know. Personally I would start with the basics and make sure that FIP and cam timing are correct and that the crank sensor is OK.
 
Good point Datatek, I will scope the crank sensor to begin with. Will take be a little longer to check fip and cam timing, Trouble is the vehicle is at my storage place 6 miles from home so checking things out becomes a little drawn out.
I do appreciate all the replies and suggestions, thanks to everyone who has chipped in :)
 
You must log in or register to reply here.

Similar threads

B
Non starting p38 diesel
Replies
0
Views
589
Bribull
B
jimmacD
Back to the P38 house of pain!
2
Replies
21
Views
1K
Grrrrrr
Grrrrrr
tarphenry
p38 diesel
Replies
15
Views
625
tarphenry
tarphenry
nevillen
To Super Diesel Or Not To Super Diesel?
Replies
8
Views
818
kermit_rr
kermit_rr
steveshone
p38 fuse box following conversion from petrol 4.6 to diesel 2.5
Replies
7
Views
1K
mystery
mystery
Back
Top