[V8] Dumping Fuel

dsaad at icehouse.net dsaad at icehouse.net
Thu Mar 10 12:03:34 EST 2005

If the #3 injector is unplugged, does the motor run OK (no fuel pouring out the
tail pipe)?

If so, it would seem the only choices are a short somewhere or a bad ECU.
You seem to have ruled out the injector already. Never hurts to double check
things though - especially when there is a language problem.

If I remember correctly, the ECU bank fires the injectors - in other words, two
injectors fire at once so if #3 is stuck on, its mate (which one I dunno) should
also be stuck on.

If I am wrong, and the ECU fires each injector individually, it is plausible the
ECU is bad. It may take a tool like an Oscilloscope to really see what is going
on though. I suppose there is some bizzare failure mode the driver transistor
could be in.


Quoting cobram at juno.com:

> A member of the V8Q brotherhood from Nicaragua, of all places, found my
> meager web site, and after a little correspondence, has me stumped.  I
> asked him to join our list, but he doesn't speak a word of English.
> 1990 V8Q with a 7/89 build, 190K kilometers, used to be some ambassadors
> car, dealer maintained till the day he got it.  He says one morning the
> car started billowing smoke out the tailpipe along with raw gas blowing
> out the tailpipes.  He shuts it down, replaces Fuel Pressure Regulator,
> pulls codes (all 4444's-no codes)  starts it up again, and she's still
> smoking like crazy, and spitting raw gas out of the exhaust.
> At this point I tell him to check the plugs....#3 cylinder is SOAKED,
> rest of the plugs look alright.  Bad injector I tell him, but I also tell
> him to check the pulse first.  I am astonished that he didn't hydrolock
> the engine.  He tells me the "noid" light is blinking fine when tested
> via the self check and when cranking (with the plugs out of the engine),
> BUT, he's getting a big gasoline fog cloud out of #3 cylinder that stunk
> up half the neighborhood.  Damn, so I have him swap the new injector for
> one of the others, he puts the plugs back in......and the thing is still
> smoking like a deranged crop duster, still at #3.  He says he went
> through 5 liters of gasoline in about 3 minutes running the car.
> Anyone have an idea of WTF is going on here???  The injector pulse is
> normal, if it was a fuel rail problem it would effect more than one
> injector, if it was the computer he'd get a solid pulse at the injector.
> Or is my logic off here somewhere?  I've never come across nor heard of
> anything like this on a V8Q before.
> Muchas Gracias and BCNU,
> http://www.geocities.com/cobramsri/
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