I've been working at an LS1 conversion into a 1983 Jaguar XJ6 for a good while now. It has a standalone loom from 12volt Customs (which they said they tested before shipping), controlling everything related to the engine ignition, including the fuel pump - none of the original Jaguar electronics are being used apart from the dash instrument cluster.
The engine will turn over for a few seconds, make a loud pop through the exhaust headers (no mufflers or cats at the moment, but the oxygen sensors are there), and either:
- through extension leads to connect the battery from a distance, the voltage will drop too low right after this pop and everything will turn off for a few seconds (including the OBD reader I have)
- with the battery directly connected, it will slow down a little after the pop and the starter will occasionally stop rotating for a moment. The voltage stays high enough for the OBD reader to stay on. The pop will occur every ~5 seconds.
I had VATS disabled, which I believe is evident as the fuel pump works fine (from what I've heard, VATS will disengage the fuel pump relay). There is also fuel pressure; it sprays everywhere if I remove the fuel hose (oops).
The OBD reader only detects RPM (I think it was showing about 400) around the time that the pop occurs, instead of immediately as the engine spins. Is this normal? The reader isn't showing any fault codes.
The PCM is off a manual Commodore, but is connected to an automatic. The guy that sold it to us said it would still work. He disabled the VATS and gave it a tune. Could the tune be the issue?
The IAT sensor reads around ambient temperature, and the pressure sensor reads ambient pressure. I hope that rules out two potential causes. I can record the details of every sensor if nothing that I've written so far seems to point at anything specific.
I have never had the engine started since we bought it off eBay a long while ago. It was missing many parts, one of which being the crankshaft sensor. I replaced it, but am not sure if it's faulty. The OBD reader did not read any RPM before the sensor was installed, and the engine wouldn't pop, it would just spin indefinitely (which is probably obvious). There are no missing parts now; everything on the loom is plugged in apart from the A/C compressor/pressure sensor plugs.
In case this information is relevant, this battery has 680 CCA. I have another battery with 640 CCA that dies the moment the starter solenoid engages, however it works fine in my dad's turbo Ford Territory. I assume the starter motor is just old/corroded internally? I don't believe there is a short anywhere.
Finally, just to give as much information as I can, the smell after a pop isn't particularly pleasant. It smells like something burning, but not the typical fuel smell. I don't think it's electrical burning but it has a similar harshness. There is no smoke.
Any help will be very much appreciated... I've been working on and off on the car for probably 5 years now. Maybe I'll take you for a drive in it, once I get it registered (give it another 5 - 50 years, optimistically).
