Hi folks,
Long time lurker, first poster. I have a Leon Cupra R which I've owned for a few months that I'm having real problems getting to start. I've used the search and read numerous threads, but can't find one that exactly matches my problem (or where they do match, the posted solutions seem not to work).
I'm looking for some help either by way of pointers to local experts who I can pay to come out and help, or advice on possible causes and things to check.
It's a long story, so I'll try to summarise a bit, but will doubtless omit something important in doing so:
- Car rebuilt after a few years off the road,
- running BAM engine with turbo upgrade and custom map,
- following rebuild the car ran perfectly for several weeks then while driving stuttered and died,
- will not restart. Engine cranks but never fires,
- no useful fault codes logged.
AA arrived, suspected crank sensor had failed so towed back to the garage where it was built.
- crank sensor changed (no effect),
- testing revealed fuel pump isn't running and no sparks at any plugs,
- fuel pump does not prime when door opened,
- fuel pump relay and various other swapped with known-good parts from a running Mk4 GTI to no effect. The Golf still runs with the Leon's relays too,
- ecu removed and checked. Water damage apparent (got damp during storage). Ecu replaced with what we believed to be a known-good unit. Map & imob transferred.
When we fitted the new ecu, we got one rough start followed by it cutting out, then back to the original symptoms.
Still no fault codes.
At this point we got an auto electrician in to help. He's not a VAG expert but he checked what he could. All continuity tests on the loom to sensors/actuators passed ok.
At this point we began to suspect the replacement ecu might be at fault. We got a contact at an ecu specialist from the auto electrician, and sent the ecu off for bench testing.
Turns out we weren't dealing directly with the testing firm, but through another third party. Got very confusing reports back, first the ecu was fine, then it wasn't, then that it could be repaired, and then finally that it was totally irreparable. Don't really know what was done or what state that ecu was in.
Next, we sourced another definitely known-good ecu and installed this without changing the map or imob coding (expecting it'd start then cut out with an imob fault). Same result - engine cranks but will not fire.
I'm worried that something in the car is killing the ECUs. Is that likely/possible?
I'm now pretty much out of ideas. I'm neither a mechanic nor an electrician, but have a reasonable knowledge of electronics and a basic working knowledge of engine stuff.
Does anyone have any suggestions for further diagnostics I could try? Have vagcom and multimeters, but not much more specialist than that.
Or does anyone know anybody really good with this stuff around west central Scotland who it'd be worth getting out or taking the car to?
Thanks for any & all help!
Sent from my Nexus 6 using Tapatalk
Long time lurker, first poster. I have a Leon Cupra R which I've owned for a few months that I'm having real problems getting to start. I've used the search and read numerous threads, but can't find one that exactly matches my problem (or where they do match, the posted solutions seem not to work).
I'm looking for some help either by way of pointers to local experts who I can pay to come out and help, or advice on possible causes and things to check.
It's a long story, so I'll try to summarise a bit, but will doubtless omit something important in doing so:
- Car rebuilt after a few years off the road,
- running BAM engine with turbo upgrade and custom map,
- following rebuild the car ran perfectly for several weeks then while driving stuttered and died,
- will not restart. Engine cranks but never fires,
- no useful fault codes logged.
AA arrived, suspected crank sensor had failed so towed back to the garage where it was built.
- crank sensor changed (no effect),
- testing revealed fuel pump isn't running and no sparks at any plugs,
- fuel pump does not prime when door opened,
- fuel pump relay and various other swapped with known-good parts from a running Mk4 GTI to no effect. The Golf still runs with the Leon's relays too,
- ecu removed and checked. Water damage apparent (got damp during storage). Ecu replaced with what we believed to be a known-good unit. Map & imob transferred.
When we fitted the new ecu, we got one rough start followed by it cutting out, then back to the original symptoms.
Still no fault codes.
At this point we got an auto electrician in to help. He's not a VAG expert but he checked what he could. All continuity tests on the loom to sensors/actuators passed ok.
At this point we began to suspect the replacement ecu might be at fault. We got a contact at an ecu specialist from the auto electrician, and sent the ecu off for bench testing.
Turns out we weren't dealing directly with the testing firm, but through another third party. Got very confusing reports back, first the ecu was fine, then it wasn't, then that it could be repaired, and then finally that it was totally irreparable. Don't really know what was done or what state that ecu was in.
Next, we sourced another definitely known-good ecu and installed this without changing the map or imob coding (expecting it'd start then cut out with an imob fault). Same result - engine cranks but will not fire.
I'm worried that something in the car is killing the ECUs. Is that likely/possible?
I'm now pretty much out of ideas. I'm neither a mechanic nor an electrician, but have a reasonable knowledge of electronics and a basic working knowledge of engine stuff.
Does anyone have any suggestions for further diagnostics I could try? Have vagcom and multimeters, but not much more specialist than that.
Or does anyone know anybody really good with this stuff around west central Scotland who it'd be worth getting out or taking the car to?
Thanks for any & all help!
Sent from my Nexus 6 using Tapatalk
