From my trouble shooting I have found the reason number 4 cylinder isn't working is that it has the wrong voltage. Testing it I found it to be way low. Unfortunately I haven't found my manuals since I moved. Any suggestions as to where to start hunting? I replace the whole harness 4 years ago. Thanks Chris
'87 740T Injection problems
Jul 29, 2005
2 Replies
The most likely place would be the ballast resistors, in a square pack mounted to the body in front of the left fender well, right beside the battery (at least that's where they are in my '85). You can unfasten the connector and remove the resistor pack if necessary for testing or replacement - it may be just the connector anyway. There is one resistor per injector, in series with the 12 volt supply. Wrecking yards would be a good source if you have to replace it since they aren't a common failure.
Mike
You have probably got one of the four ballast resistors gone duff. You may have to replace the whole four resistor unit. Follow the wiring back from the injectors to the resistor unit. That is what needs replacing. You should be able to find one in a scrap/wreckers yard.
All the best, Peter.
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