Frequency valve and RPM relay

[Jan@xxxx]

Hello again,

First of all I would like to thatn everyone that responded to my 
previous question about my backfiring engine; I will pass on the info 
and hope they can solve it at the shop.

When I got my car out of its home (http://www.cartainer.nl (only in 
Dutch, sorry!!!)) I noticed a ticking sound by the engine, this
turned out to be an arcing spark plug lead on the left bank, I put it 
back the right way, so the ticking is solved now, but the engine
still backfires.

Since I had gotten a tip that concerned the frequency valve I decided 
to look where it was located (may seem dumb, but I really didn't
know). Well I found it, but finding it made me doubt wheter it
actually works or not: I read the section in the Work Shop Manual on 
the subject and did some searching in the archives; according to
those the FV should be buzzing at 70Hz, with a changing dutycycle 
between 20% and 80%.

70Hz should be easy to hear or feel I would think, but I DO NOT hear 
nor feel it buzzing... Supposing it does not work; what effects could 
this have on engine performance? If I understand the explanation
right it would cause the engine to run lean, not rich as mine is
doing. Or am I completely wrong here???

I also found out that I will have to check the electrics to my fuel 
pump some day soon: as I reported earlier it does not shut off
throught the Inertia Switch, today I discovered that it even runs 
without the RPM-relay in place: if I put the ignition to II the pump 
starts humming and keeps doing so untill I turn back to I or 0.

Could this have some influence on the ECU too? The RPM relay does
give it some signal, so it wouldn't surprise me at all...

Please answer me ASAP, as my appointment with the shop is less than a 
day away now... Thank you VERY much in advance,

JAN van de Wouw
Thinking Different... Using a Mac...
Living the Dream... Driving a DeLorean...

#05141 "Dagger" since Sept. 2000

check out the Delorean-Files at:
http://www.deloreanfiles.nl/
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