I'm trying to troubleshoot a weird problem. My D2 with Thor has recently been re-converted. The nasty mixer system has been ripped out and replaced with a Romano multi-point system. It's running beautifully, but only after I had driven some distance did I realise that it's using some petrol as well as LPG. It's using a ratio of around 10:1 LPG to petrol. When I pull the fuel pump fuse it runs rough, which is what you would expect if it has been tuned with some petrol going through as well as LPG. So far Steve my installer is baffled as to the cause. I was wondering whether it is possible to disconnect individual petrol injectors in order to discover whether the problem is related to an individual cylinder, but the injectors are buried deep under the inlet manifold. Is there a place where the wires to the injectors are easily accessible? Or does anyone have a better idea how to track the problem down?
How to isolate individual petrol injectors (Thor)
- Thread starter ddriver
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- Rushden, Northants, UK
The injector feeds should be re-routed to the gas valves by the gas ECU.
If you're still using petrol AND gas there should be over-rich symptoms on one cylinder, but most likely is a wiring issue where one injector feed isn't changing from petrol to gas.
Peter
If you're still using petrol AND gas there should be over-rich symptoms on one cylinder, but most likely is a wiring issue where one injector feed isn't changing from petrol to gas.
Peter
Thanks Peter, but how to diagnose it?
It's probably not running rich on any cylinder because the system has been mapped with the fault in place. If there is one cylinder that is receiving petrol the system will be sending less gas to that one. If I could cut the petrol to that one I should see it running rough.
I was thinking I could disable each petrol injector in turn, but they seem to be so inaccessible that I can't easily do that.
It is of course possible that there is a faulty component in the new system, but without knowing what it is we would just be guessing and replacing everything, and then it still might not fix it.
It's probably not running rich on any cylinder because the system has been mapped with the fault in place. If there is one cylinder that is receiving petrol the system will be sending less gas to that one. If I could cut the petrol to that one I should see it running rough.
I was thinking I could disable each petrol injector in turn, but they seem to be so inaccessible that I can't easily do that.
It is of course possible that there is a faulty component in the new system, but without knowing what it is we would just be guessing and replacing everything, and then it still might not fix it.
- Posts
- 3,275
- Location
- Rushden, Northants, UK
Most of the LPG kits have a mini-loom that you wire into the engine loom, cutting feeds to the petrol injectors and routeing them through the gas ECU.
When Philip did his installation he had to cut open the main loom in the engine bay and pick out the injector feeds.
I've got the Zavoli stuff kicking around, I'll see if I can dig that out to give you a start.
You could also unplug the Bosch ECU and bell out the injector feeds from there to the gas ECU.
Peter
When Philip did his installation he had to cut open the main loom in the engine bay and pick out the injector feeds.
I've got the Zavoli stuff kicking around, I'll see if I can dig that out to give you a start.
You could also unplug the Bosch ECU and bell out the injector feeds from there to the gas ECU.
Peter
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