Re: need frequency valve help

["Robert Rooney" <dmcvegas@xxxx>]

When the frequency valve is operating it will emit a loud buzzing 
sound. Once it is plugged in, believe me you will notice it! The 
problem itslef my not be a bad valve but rather a poor connection. I 
had the exact same problem with my car. As it turns out someone had 
pulled on the wires to unplug the FV rather then gripping it by the 
plug. Try this: Unplug the frequency vavle and inspect how far into 
the plug the wire contacts are. You may just need to push the wires 
back down into the assembly. If you're not sure exactly how the wire 
connection should look, unplug the cold start vavle and use it's plug 
as a referance.

-Robert
vin 6585



--- In dmcnews@xxxxxxxxxxx, "Walter" <Whalt@xxxx> wrote:
> I've had an on-going cold acceleration problem in my Delorean and 
haven't
> had much luck getting advice on how to fix it. Maybe someone on 
this list
> can help?
> 
> So far I have tried unplugging the electrical connection to my 
frequency
> valve, and it makes absolutely no difference to how the engine runs.
> 
> The engine coughs, sputters, pops, and runs rough until it 
completely warms
> up. When I force the engine to run richer by pulling a vacuum on 
the
> delayed side of the control pressure regulator, then the engine 
runs fine!
> I have checked the fuel pressures and they are within specs.
> 
> My question to the group is: How can I tell if my frequency valve 
is
> working? I've tried unplugging it and this makes no difference. 
I've tried
> unplugging the Lambda ECU and this makes no difference either. 
I've put a
> volt meter across the wires going to the frequency valve and measure
> nothing. I realize that a volt meter is probably the wrong tool 
for this,
> but I don't have access to an oscilloscope. Is there some other 
diagnostic
> tool that is appropriate here? I could check for flow with a fuel 
pressure
> gauge, but I hate to take those connections apart if I don't need 
to. I do
> get continuity through the coil, but that won't help if nothing is 
going to
> it.
> 
> For those of you who like to read, here is an earlier message I 
wrote to the
> DML that never got posted. It explains more of my symptoms:
> 
> What can cause a Delorean to hesitate during acceleration, but 
forcing the
> control pressure regulator to make it run richer cures the 
problem? I've
> checked the fuel pressures, and they are all normal. I get primary 
pressure
> of 5.1 bar. The control pressure regulator gives 2.9 bar with cold 
engine,
> 3.7 bar with fully warmed up engine.
> 
> Pulling a vacuum on the delay side of the control pressure 
regulator drops
> the fuel pressure under 2 bar and cures all my problems. But, the 
fuel
> pressure isn't supposed to be that low. So is this compensating 
for some
> other problem? And if so, what is it?
> 
> At idle, my vacuum reading is 15 inHg, but it jitters +/- 2.5 
inHg. Is this
> normal? My vacuum at 2000 rpm is 17 inHg and smoothes out. Is 
this a
> symptom of a stuck valve or is this normal?
> 
> This problem has been intermittent in the past and would only 
happen to a
> cold engine. Now it happens all the time, and it doesn't really 
matter if
> the engine is cold any more. Now even after the engine is warmed 
up, I get
> hesitation, coughing, sputtering and even backfiring.
> 
> When I start the engine, it tends to stall. Any pressure on the 
accelerator
> makes the engine hesitate, cough, sputter and pop. When I release 
the
> accelerator, the engine speed actually picks up for an instant and 
then
> drops back to a rough idle. This keeps up until the engine is 
hot. Before
> I drive the car, I have to let it warm up for at least 5 minutes. 
After the
> engine is fully warmed up and I turn it off and let it sit for 30 
minutes, I
> have to let it warm up all over again before I can drive it.
> 
> Walt Tampa, FL