P38A Thor 4ltr meltdown

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S

supapete

Active Member
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505
Location
West wing I think
Morning all. I'm in serious trouble. Holidaying in Spain. It all started with EAS 35mph on the bump stops for the last 500 miles towing a caravan. Got a new compressor and then a Hawkeye faultmate to clear the fault. It did but the fusebox caught fire. Literally. Got new box and just-in-case relays. Alternator wiped out. Got new alternator. Voltages all OK. Started and ran like a dog. 0.445v on lambdas no other fluctuations or readings. Got new lambdas on way from island 4x4 who I trust. Got an engine management ECU on the way with correct part number. I would really like someone knowledgeable to come with the cavalry. Could someone help me with the next logical steps progressing from the tale of woe. When I say it runs like a dog i mean it starts spot on, pulls away smoothly but as soon as I ask for acceleration it splutters and spits. If I floor it it spins and kicks down so I can do 35mpj or 60+ mph
. Thanks all in anticipation. Btw. I have searched and found plenty but everything goes off the exact topic. Regards. Peter.
 
Have you found and isolated the cause of the fusebox fire?

They do get old and start burning out, but to actually catch fire is rare.....so they may have been external influences involved like a current spike or shorting out of a relay.

All sorts of electrical spikes could have been delivered through the car when the fusebox went pop, so I'd be checking all wiring looms and the Engine and gearbox ECUs....they could have been fired by a spike of current.

Remember if you replacethe engine ECU, you will need to resync the BeCM to the ECU to allow it to start.
 
Yep. Sounds like it's fried the engine ecu. When these fuse box's let go they usually take the other ecu's out with it.
Hopefully it's just the engine ecu it's cooked.
 
Thanks for the prompt replies. The abs, EAS, transmission and all are showing no faults. The only faults showing anywhere are, as you've probably guessed are 13; PO135 O2 probe heating.....

.5; PO155 ditto bank 2.

Would it be too much to hope for that just the lambdas have had it.
From the evidence in the fried fuse box it looks like 8 years of being drenched with coolant. A progressive thing judging from the charring between a couple of connectors underneath and a film of blue and pink moisture on what was left around the SRS fuse area. The SRS fault disappeared after the new fusebox. All the relays tested OK and the only blown fuse was the SRS. I've replaced the known culprits anyway like the abs, EAS and AC fans. In fact, after all the rectifications I've mentioned the motor outwardly seemed back to normal. It was only after driving it the horrible running showed up. I've looked at the body electrics security which tells me it's locked and "when locked can't be unlocked". Does that mean I can't install the engine management ECU? Blimey. Is this a disaster?
 
If you install the replacement engine ECU you will have to sync the BeCM and the ECU to eachother.....this is done using a diagnostic tool like the Faultmate Extreme, Nanocom or T4 Testbook.

You can get a resync tool from Blackbox Solutions which does the job for around £100-120 from memory....
 
if it caught fire why didnt you claim on your insurance ? Electrical fires are a car killer and you could be chasing your tale and forking out shed loads to get it back to normal running if there is normal running on a p38. I wish you all the luck in getting it back to normal. P38s dont like France. My STAINLESS exhaust rotted and burnt a hole in the air line at the rear so on its stops in France and the AA recovery from Portmouth on the way home
I always carry a fire extinguisher in my cars as they are all on lpg
 
Thanks again. I omitted to mention I'm yet to confirm or otherwise my diagnosis data
. Because of my location and predicament, I've ordered parts in advance of basic research.also posted on here in advance. As nice as southern Spain is, I don't want to be marooned here. I'll bechecking resistance across the lambda






heaters and checking for 12v
; Looking for melted or shorted cables. I'll talk to P38 spares when they open and get a sync mate sent out. I'm not even dreaming of the becm being shot. There aren't any fault codes popping up. Thanks again, I'll report......... I've yanked the engine ECU out and scrawled around underneath. Absolutely no charred cables. I've got lambdas, ECU and sync mate on the way. Just need to check on cabling to do my continuity, voltage and resistance test. I've come across a really informative thread on this forum where the poor guy suffered the same symptoms lambda and ECU wise as me. He cracked it with what I have on order. Fingers crossed. The whole car didn't catch fire. There were actual flames coming out from around the SRS fuse area and the board itself had burned away. I'm paranoid about leaving my 38 with garages so, an insurance claim never entered my head. All the RAC would do was tow me to an agent God knows where. I'll report back.
 
Could I ask a final question, please? When I go about fixing the ECU and lambdas in, is there a procedure? In other words could I banjax something by, say, putting the lambdas in and then trying the motor out? Or ECU in without changing the lambdas? Thanks in anticipation . Peter.
 
Just multimetered. I know I should only get 12v on one pin off the loom going to the lambda. I've got two pins showing 12v one showing 0.44 which I expect and one showing zero. I've got 13 ohms across the lambda . So, double check the loom for horribles before I replace the ECU . Do I assume correctly that if the heater feed and return aren't shorted, the ECU has had a hit? Regards
Peter.
 
A bit more research. (Regrettably I don't know everything from birth). It seems I should get 12v at the two heater connectors from the loom with ignition on but no engine running. One from the fusebox and the other from ECU which goes to ground on firing up, later to pulse. So, all seems well. Damn matron's found me, I'll ask her. Any comments?
 
Well, a big thankyou to the guys who've tried to help me. Cleaned the crud of ages from a couple of connectors on ECU and new Bosch lambdas. Still gonna put new ECU in.
 
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