gt/e paul Posted October 27 Share Posted October 27 Pending attempting to eventually start to restore my gt/e I thought it'd be a good idea to get her running again to fully evaluate engine wise what needed doing. I'd put her away as a fully running car but now 10 years have passed without anything moving . One thing that had always niggled me was the cold start injector never worked so today I set about looking into it I thought must be pretty simple affair with thermal time switch and 5th injector. I've quite limited knowledge with electronic things but on a bit of research it was said that if I connect a bulb to the blue plug it should light when cranking ..... it didn't then I changed the thermal time switch it still didn't light . I've earth Continuity from one pin of the blue plug and to the engine and earth continuity from one pin of the brown plug to engine.... I then tested for continuity between brown plug and blue plug and had absolutely nothing... I had assumed it'd work like this as its a thermal make and break switch or maybe I'm totally wrong.... Everything else worked eventually foredeck up and ran on all four just as she always did . Any advice greatly appreciated Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted October 27 Share Posted October 27 Test for +12v ,the negative is switched Quote Link to comment Share on other sites More sharing options...
gt/e paul Posted October 29 Author Share Posted October 29 On 27/10/2024 at 22:13, Jessopia74 said: Test for +12v ,the negative is switched How can I test for this please? On the cold start valve if I test for continuity across the two terminals it's showing the switch as closed Sorry for being perhaps a bit vague these things don't appear to operate as id think I've also swapped the ecu to see if that's at fault but it's still the same Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted October 29 Share Posted October 29 Rather than write it out, there are loads of articles on other makes that still use the same system. So wire colours should be largely ignored, but the function of the individual components within the system is the same. Main difference on L and LE is in the AFM( Air meter flap), but not going to stop you testing the cold start circuit as such. https://hpsimotorsports.com/blogs/tech-articles/gregs-bosch-l-jetronic-fuel-injection-idle-adjustment-diagnostic-and-tune-up-page Quote Link to comment Share on other sites More sharing options...
Trooker Posted October 29 Share Posted October 29 9 hours ago, Jessopia74 said: Rather than write it out, there are loads of articles on other makes that still use the same system. So wire colours should be largely ignored, but the function of the individual components within the system is the same. Main difference on L and LE is in the AFM( Air meter flap), but not going to stop you testing the cold start circuit as such. https://hpsimotorsports.com/blogs/tech-articles/gregs-bosch-l-jetronic-fuel-injection-idle-adjustment-diagnostic-and-tune-up-page Wow Jess, that’s quite a find! I haven’t read through it all tonight but it looks comprehensive. A few years back I found myself on the e30zone.net as they had a decent overview of the L and LE jetronic in a handy wiki but not fault finding like this. 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted October 29 Share Posted October 29 4 minutes ago, Trooker said: Wow Jess, that’s quite a find! I haven’t read through it all tonight but it looks comprehensive. A few years back I found myself on the e30zone.net as they had a decent overview of the L and LE jetronic in a handy wiki but not fault finding like this. The Alpha guys forums is full of great info. Not sure it’s got anything to do with Bosch as such, more to do with the Alpha build of that era 🤣 1 Quote Link to comment Share on other sites More sharing options...
gt/e paul Posted October 30 Author Share Posted October 30 brillint many thanks for this i shall take a better look when i get home ive searched and searched for something that goes into detail ,detail id understand as electrical systems baffle me .im a mechanical and metal guy Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted October 30 Share Posted October 30 just had a read of that jetronic info link . very usefull and i learnt some things i didnt know . not that it applies to my 2.2's anyway but i didnt know that the 5th injector on 2 litres only fires whilst cranking ( temp permitting) . im sure the haynes wiring diag contradicts this but il be looking later at the diags to see . pity the info wasnt on the later le2 with the idle control valve and little ecu . however mines behaving at the moment ( all on its own!) but i did contemplate making my own ecu for it . at the end of the day it monitors engine temp and speed and varies the voltage to a valve . how hard could it be ? Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted October 31 Share Posted October 31 18 hours ago, cam.in.head said: just had a read of that jetronic info link . very usefull and i learnt some things i didnt know . not that it applies to my 2.2's anyway but i didnt know that the 5th injector on 2 litres only fires whilst cranking ( temp permitting) . im sure the haynes wiring diag contradicts this but il be looking later at the diags to see . pity the info wasnt on the later le2 with the idle control valve and little ecu . however mines behaving at the moment ( all on its own!) but i did contemplate making my own ecu for it . at the end of the day it monitors engine temp and speed and varies the voltage to a valve . how hard could it be ? Never been able to find anything on the aux controller for the later setup. Think it’s because it was such a short period before the Motronic landed, so not that much about. Not even Bosch manuals that can be found for quite a few variants. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted October 31 Share Posted October 31 this is true . it was around 83/84 ish to 86 on the carltons and senators . good idea in principle but the ecus are a bit temperemental . ! Quote Link to comment Share on other sites More sharing options...
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