Vacuum leaks ([DML] Re: Stalls after starting)

["content22207" <brobertson@xxxx>]

Vacuum leaks are fuel economy killers. Because engine is breathing
elsewhere than over air sensor plate, you have to open it further to
keep some sort of ratio that will combust. Ever notice that people
with vacuum leaks usually crank fuel mixture screw clockwise? (myself
included). You'll smooth the idle out, but at the cost of extra fuel
metered into engine.

PRV is a bit different from familiar domestic blocks. Will suck air
from the wierdest places (pull out dip stick -- vacuum leak). In the
bad old days loose valve and timing chain covers just leaked oil. On a
PRV they let air into engine. No joke: spray ENTIRE block with leak
detector of choice. You'll be amazed at what you find. Long gone are
days of just replacing a few hoses and tightening down carb/intake
manifold.

Re: fuel economy -- noticed on an eBay auction for repro window
sticker that original EPA was only 19 mpg. Since highway is in low
20's, that means upper teens in town should be normal (15 mpg may be a
bit low, but obviously couldn't be more than 17 or so). Remember the
RPM's we're pulling (why does my DeLo bring out the Mario Andretti in
me?). I notice most on highway. Virginia's lower speed limits yield
better economy than North Carolina. At time of original EPA cars
percolated 55 mph / 2000 rpm. Now I'm driving 80 mph / 3000 rpm. 

Re: John Hervey's suggestion to diagnose distributor plunger letting
fuel out to injectors, I'd recommend popping out an injector itself
and placing in neck of coke bottle. If you actually want engine to run
like that you'll have to seal injector port. I used to do that with
3/4" hose and a plug streched over lip. Worked but was difficult to
install. When I replaced injector seals made an internal plug from old
seal and a bolt (smooth portion of shank). Much easier.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "K. Creason" <dmc4687@xxxx> wrote:
> That's interesting John. Now I've got to speak up and my twists to this
> situation.
> 
> I've been monitoring this thread because I have similar issues after
my 30k
> miles service, and leaning my car out. I've probably leaned it out tooo
> much, but I was trying to find out why I only get 15 city mpg; how
hard I
> drive makes almost no difference.
> Early morning or four hour parked starts smell very gassy and run rough,
> almost bad timing-like. I did have a bad vacuum hose on the timing
advance
> unit, but that is fixed. I'm thinking something else is losing
vacuum and it
> takes time to build it back up after starting? Say the system loses
vacuum--
> how long does it take the system to get it back up? And if you lose
vacuum
> in one part, does it effect other parts, like the air mode switch?
> Hmmm, reminds me that last summer I had starting issues if the car
had been
> sitting in the hot sun for all day. Never did solve that, it just became
> less of an issuel. Is that the fuel accumulator? Could that be
working in
> tandem or is that my real problem?
> 
> -----Original Message-----
> From: John Hervey [mailto:john@xxxx]
> Sent: Monday, June 23, 2003 11:23 PM
> To: dmcnews@xxxxxxxxxxxxxxx
> Subject: RE: [DML] Re: Stalls after starting
> 
> 
> As David says the CPR ( Control Pressure regulator ) Warm up
regulator could
> be going bad, but also the 02 adjustment could be adjusted to lean not
> allowing the control plunger in the fuel distributor to rise high
enough. If
> it doesn't rise then very little or no gas goes to the injectors. If
you try
> to start it and it dies, Then pull a plug as fast as you can and see
if it's
> wet or dry.
> John Hervey
> 
> 
> -----Original Message-----
> From: David Teitelbaum [mailto:jtrealty@xxxx]
> Subject: [DML] Re: Stalls after starting
> 
> The first thing that comes to mind would be to check the control
> pressure regulater aka the warm-up regulater.
> 
> 
> 
> --- In dmcnews@xxxxxxxxxxxxxxx, "painintheass7565" <advantics@xxxx>
wrote:
> > Howdy. I have two D's and one runs like a top and one has this
> > problem. I starts right up but unless I keep my foot on the gas it
> > stalls out.
> 
> 
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