You can use a 9 volt battery to test each injector with two pieces of wire, One attached to + and one to - Touching the other ends of the wire to the two pins on each injector very briefly, the injector should click open/closed. This should confirm the coil and pintle operation, but it will not determine if the injector is leaking…ie not seating properly. Did you check the fuel pressure regulator as previously mentioned ? SD
Hi Ivan, SD’s advice is of course, spot-on! Once you “unplug” an injector it is now electrically disconnected from the car, so touching one terminal is not going to do anything for you. Also remember that the injectors were not designed to operate at full twelve volts! Nine volts is enough for testing!
Thanks for the data: I did check the regulators ( both were dry) I will now check the injectors as you suggested…
Thanks, Sloth
Hey y’all, newbe here. Im having the same problem. What did you find Sloth? I have a 84 JSX HE V12 I have owned for 20 years. Is has been stored for 10 yrs. I started it couple times a year until I experienced leaking fuel lines from the fuel tank. It sat for 2 years until I got around to replacing the leaky fuel lines. When I started it, I noticed raw fuel & smoke coming out of the drivers side exhaust. I have never esperienced his before. I sent the injectors off to Dave in Florida thinking I had some stuck open and he rebuilt all of them for me. After installation I still have a huge amount of fuel & smoke exiting my drivers side exhaust pipe. I have pulled a vacuum on both fuel diaphrams and also checked where the hoses connect to the manifolds while it was running and they do hold a vacuum and I see no fuel entering the intake manifold. There is also fuel in the oil. It runs, however, it does not run smoothly.
Thanks!
Jay
Check that you have spark on that cylinder bank
Excellent suggestion! Will do this weekend.
Thanks,
Jay
There have been some reports of injector wires shorting to ground, causing injectors to remain open. The injector harness on V12s suffers greatly from years of being baked by engine heat
Cheers
DD
Doug,
I haven’t had this exact fuel problem happen to me but I suspect that
you could confirm if this was happening by listening to the fuel injectors
with a mechanics stethoscope while someone cranked the engine. I would
remove power from the fuel pump first by tripping the inertia switch to
avoid adding any more fuel while doing this. You should hear clearly
defined clicking from each and every fuel injector while cranking the
engine. If not, then it might be an electrical problem with the power
resistor or fuel injector wiring grounding out.
Paul
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Whatever you do, check the oil level in the sump. If it’s HIGH, it may mean that a jammed injector or whatnot has dumped so much fuel into the engine that some of it has been trickling down into the oil. You don’t really want to start it like that; you’d want to fix the problem first and then change the oil before starting.
Yes, it happened to me. One bank suffered a short in the injector harness, all injectors wide open on that bank. Sudden loss of power, raw fuel coming out of exhaust, looks just like Marelli Meltdown (with much the same potential result).
You should have seen the smoke when i started it, after fixing it. Must have been half a gallon of unburnt fuel in the exhaust system.
Hi my problem was solved the man in fla
Complete inj. Rebuild…
Excellent information! I will troubleshoot y’alls scenarios this weekend (hopefully). Mark, how were you able to find the shorted injector wiring?
Thanks,
Jay
Hi jay
Are you shure the injectors are open constantly.?
After you replace bad oil so you can fire it up, check the cold start plug (found at left frount corner of motor) it tells ecu to send more fuel when cold. It,s a single wire going to it.