Re: [DML] cold engine acceleration problems

["Walter" <Whalt@xxxx>]

DMC Joe & Robert --

I'm going to read up on the acceleration enrichment circuit as soon as I get
a chance.

My engine accelerates fine after it has warmed up. Well, that is fine for a
Delorean which is about up to par with my '84 Olds Delta 88. I think in a
race with my Olds, it would be a close match, but the Olds would probably
win.

When my ignition is on, but the engine isn't running, I think I hear the
frequency valve buzzing. I suppose that's what that noise is. With the
sound of the engine running, this is drowned out. My car has about 11.5K
miles on it, so I don't think it is due LAMBDA problems yet, but with it's
age, I don't know.

My mechanic said he connected a fuel pressure gauge and showed that the
control pressure regulator was out of range. I think he said I had 5 bar
pressure when it shouldn't be higher than 3.8 bar.

I agree with Joe about my engine not flooding. The cold start valve (unless
the valve itself is stuck) cannot stay on because of a stuck thermo-time
switch. The thermo-time switch allows the cold start valve to activate, but
it can only activate WHILE the starter is running. Once the engine is
started, the cold start circuit does nothing. So even though I have a bad
thermo-time switch, this is not why my engine does not accelerate when cold.

To correct what Robert said, activation of the cold start circuit is
controlled by the thermo-time switch AND the start position. Both have to
agree (like a logic circuit) in order for the cold start valve to be
activated. If the key on the steering column is not turned far enough to
activate the starter, then the cold start circuit should not activate.

When I said that it sounds like my cooling fan switch is out of range, I was
referring to a previous post where I said that my temperature gauge reads
just above 220 degrees before the fans come on. If this were true, then
this is too hot, and the switch should be replaced. However, I'm dyslexic
enough that someone could secretly switch out my Delorean for a right hand
drive model, and I wouldn't know the difference. Well, I'm not quite that
bad, but I had a very hard time learning to read as a child. Anyway, I
cannot keep my left and right straight OR my up and down straight either
(when looking at maps & diagrams & such). So when I was remembering what
temperature my cooling fan switch activates at, the needle was pointing just
UNDER the 220 mark, not above it. (Sorry!) Never ask me for directions on
how to find someplace. I can't tell my right from left, and analog clocks
are useless to me!

In light of this, I assume my cooling fan switch is okay. Is it? I had
taken it out long ago to diagnose a cooling fan problem. When I put it back
in, I smeared some non-hardening Permatex on the gasket thinking this would
help it seal. Well, it obviously didn't. Maybe this made the seal worse?
I suppose that a thin hose clamp from Home Depot would do the trick. It
could hold it in there tighter than the OEM spring wire. I will probably
put a piece of heat shrink tubing around the new clamp to make sure neither
electrode gets shorted to anything. I call this a "bad-engineering fiasco"
because I can think of better ways to measure coolant temperature other than
sticking a hollow rubber cork in a hole and holding it on with a spring
clip. To me this looks like it was made to leak -- and leak it does, but
that may be my own fault due to the Permatex. Does a new switch come with a
new seal? Or can a seal be bought separately? Or since I've gone to the
trouble to get the thing apart, should I replace the whole thing anyway? At
close to $50 for a new switch, I think I might goop it up with more Permatex
and put a better clamp on it. That is unless y'all think the thing is
switching on at too high a temperature. What do y'all think?

I already got a self-bleeding kit from DMC Joe when I saw him at 'A Day in
the Doors'. It's just a matter of putting it on.

This car is going to turn me into a mechanic yet! :)

Walt Tampa, FL
Delorean mechanic apprentice