ECU on left hand drive E500 problem after LPG conversion

[leosch]

Hi,

I am new to this forum and would welcome some assistance. I own a much loved left hand drive E500. This was from a limited edition hand built by Porsche for Mercedes as a grand tourer.

I decided to convert to LPG. That threw up some problems because the car has 100,000 miles on it. I needed a new electrical harness because the old one had the insulation come away as soon as the top of the engine was removed. Then a crack in the neck of the radiator meant a new radiator. Those problems seemed reasonable given the car was being worked on.

But when the car went to the specialist to be converted it was purring or roaring like a cat. When he returned it, there was clearly an issue which he suggested might be the plugs. I had a new set of plugs and a new distributor cap put on it but that made no difference. I had to take it back. It turned out the engine was only firing on 4 cylinders. He tracked that to a fault on the original ECU not the newly installed one. That has gone to a company in Nottingham to be repaired now.

My question is whether this is a coincidence or something resulting from the conversion. It does seem a stretch for it to be coincidental. Has the converter done something wrong? Is it likely to be his fault?

Thanks for any assistance.

Leo

 

[kth286]

A tricky situation - I can only say I would have done good due diligence up front ie.
how many of same car have you converted, can I have some references, is the new system proven as being compatable with my engine configeration, sight of manufacturer' paperwork to support the decision on a particular system, etc etc.

 

[teddycatkin]

Seen them on LPG in Holland--so if the conversion was done properley it should have been Ok?

 

[balge59]

hi
when you say " I needed a new electrical harness because the old one had the insulation come away as soon as the top of the engine was removed. "
- is this the famous 'bio-degradeable' wiring harness problem? I think there may have been two harnesses on the engine affected, perhaps you need to check this out?

 

[Alex Crow]

the harness problem could easily damage the ecu, a very credible scenario. whenever these wiring harnesses are disturbed there is a chance this can happen, repair ought not to cost too much. if ever i change the plugs on a 104 now i always discuss the potential pitfalls with the customer, better that way...