From: <dmcnews_at_dml_yahoogroups.com>
To: <dmcnews_at_dml_yahoogroups.com>
Subject: [DML] Digest Number 2293
Date: Sunday, October 24, 2004 9:51 AM


There are 6 messages in this issue.

Topics in this digest:

1. RE: Re: End of life for idle ECU's
From: "Gary Hull" <Specialty_at_dml_IN2TIME.com>

2. Re: exhaust manifold gaskets
From: "Dave Swingle" <swingle_at_dml_dmcnews.com>

3. Re: Brake Problem
From: "Joe OBrien" <joeyoseppijoe_at_dml_yahoo.com>

4. AW: Brake Problem
From: "Elvis Nocita" <elvisnocita_at_dml_gmx.de>

5. AW: Re: End of life for idle ECU's
From: "Elvis Nocita" <elvisnocita_at_dml_gmx.de>

6. Re: Brake Problem
From: Bob Brandys <BobB_at_dml_safety-epa.com>





Message: 1
Date: Sat, 23 Oct 2004 19:41:58 -0700
From: "Gary Hull" <Specialty_at_dml_IN2TIME.com>
Subject: RE: Re: End of life for idle ECU's


I agree with the feedback loop theories, but I suspect that the multiple air
paths, fuel sources, and fuel/idle/air control circuits are simply fighting
each other for control. 

I can cause mine to hunt by manually adjusting the throttle to above 750 RPM
or by opening the needle valves.  If I leave it at 750 rpm (with the needle
valves closed) and let the idle speed motor control the idle, it starts,
idles and runs perfectly.

Gary 
IN2TIME  







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Message: 2
Date: Sun, 24 Oct 2004 04:59:10 -0000
From: "Dave Swingle" <swingle_at_dml_dmcnews.com>
Subject: Re: exhaust manifold gaskets


I'm still running my originals at 40,000 miles and 23 years, so I 
guess that's the high side (at least with respect to time, I'm 
sure there are many out there with more miles). You are seeing the 
low side. 

They **should** last more than 3 years, one problem is that if you 
run the car with the leaking for a long time, before fixing it, the 
gasket material eventually blows out and the manifolds can warp 
enough to make bad fit with the new gaskets. 

I'm not sure where you'd get stainless steel manifolds per se - if 
you are referring to aftermarket tube headers there is nothing 
intrinsically better about them with respect to sealing.

Dave S


--- In dmcnews_at_dml_yahoogroups.com, kevin creason <kcreason77_at_dml_y...> wrote:
> 
> How long do the exhaust manifold gaskets last? Low,
> high, average? Any ideas?
> I replaced all mine 2.75 years ago, and I can hear a
> little "beetling" on initial acceleration. It's not
> bad yet, as you can't hear it standing out
> 
> And why do the Delo's have this problem? Is it the
> aluminum engine and the cast iron exhaust manifolds?
> I saw on someone's site that there are stainless-steel
> gaskets. Will those work any better? Will stainless
> steel manifolds work better?
> -Kevin
> #4687








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Message: 3
Date: Sun, 24 Oct 2004 06:58:33 -0000
From: "Joe OBrien" <joeyoseppijoe_at_dml_yahoo.com>
Subject: Re: Brake Problem



I had the exact same problem on my old 66 mustang. It would almost 
pull the wheel out of my hand when I braked. It pulled to the right 
so hard it felt like just the right front was stopping the car. 
Couldn't touch the drum till I let it cool for 2o minutes after a 
run. After changing the pads, flushing & flushing the brake system 
again it still pulled. Only after I changed the front lines did the 
problem leave. The line was collapsing and causing the problem.

After getting the Deloreans and after about the first year of 
ownership I was thinking the same thing could happen. This year at 
Pigeon Forge I bought the newer stainless braided brake lines. WHAT 
a difference. Much firmer pedal and just the good feeling knowing 
your brakes shouldn't be failing you when you need them. I also 
bought the dust shields from Don Steger and couldn't be happier with 
them. Wonderful for cutting down on the brake dust. Pricey, but very 
nice.

I would suggest if you are going to be doing any brake work anytime 
soon and you drive your delorean more then a few times a year, the 
stainless braided brake lines are a wonderful upgrade for our cars. 

Joe OBrien

2524 & 16634









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Message: 4
Date: Sun, 24 Oct 2004 09:21:48 +0200
From: "Elvis Nocita" <elvisnocita_at_dml_gmx.de>
Subject: AW: Brake Problem




Daveid,
I exactly had this problem when I bought my car and drove it the first 
2-3 miles. I made it home the other 400 miles though.

Those old brake hoses absolutely need to be replaced and it doesn't 
matter if it is on a Delorean or any other 20+ year old car.

I had stainles steel braided hoses made for the front and rear.
She site seems to be down at the moment, but this guy made them:
http://www.dickhaut-specials.de/

Elvis & 6548



On a nearby Delorean I helped the owner with some brake problems. I
mention this because it turned out to have an unusual cause. When he
first got the car it pulled really hard to the right. I correctly
diagnosed a stuck piston in the right caliper. We rebuilt it and it
fixed the pull to the right. It never really seemed "right" but it
definatly was better. Some time later (a year) the car would again
pull really hard to the right after driving for a while. It pulled so
hard to the right the right front wheel started to smoke! Afer waiting
around an hour for it to cool off it would drive normaly for a while
until it would lock up again. I thought maybe the brake fluid was
contaminated and the water inside was turning into steam causing the
pressure and locking up the right caliper. We flushed and bled and got
no water or dirt out. Now I realize that was wrong because both front
calipers would have locked up if the fluid was contaminated. I have
seen this only twice and not on Deloreans. We changed the front right
brake hose and the problem has not reoccured. It seems the inside of
the brake hose comes loose and acts like a check valve. When the brake
fluid heats up the pressure cannot be relieved back to the Master
cylinder (this is called compensation) it forces the pistons on the
caliper to lock up the rotor. I am bringing this up because most of us
are driving on 20 + year old hoses. If anyone gets these symptoms they
should immediatly consider the brake hose since it is way past it's
service life.
David Teitelbaum
vin 10757







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Message: 5
Date: Sun, 24 Oct 2004 09:39:02 +0200
From: "Elvis Nocita" <elvisnocita_at_dml_gmx.de>
Subject: AW: Re: End of life for idle ECU's



And still - a good control loop can compensate any hunting of the idle,
especially the bad ones that let the idle vary with about 1Hz.

There's absolutely no reason or explanation behind an idle speed hunting 
between 900 and 1200rpm other than a badly designed control loop.
One cylinder firing better or worse won't affect the idle like that
at all, the other 5 will smooth it out !

And also there's a diference between cold and warm ! Sometimes when cold
the engine may hunt very bad but suddenly stopps to hunt when it gets warm.
And when I say suddenly I mean suddenly ! Not like it's getting slowly
better - no it's like blown away within less than a second. Like switched 
away !!!
This made me believe that it can't be just a vacuum leak or a bad
wire. And soon I'm gonna start to test it.

Of course everything needs to be in a good condition, a 23 year old 
O-ring or a totally broken O2 sensor need to be serviced anyway.

Elvis & 6548


>From my experience what I have found as a cause for a hunting idle is
vacuum leaks for sure but mostly 1 or more cylinders are not firing
evenly. A dirty fuel injector, a bad ignition wire, low compression, a
valve out-of-adjustment, is the kind of thing to look for. MY theory
is when the motor fires on the low cylinder the engine slows down. The
idle ECU tries to compensate by increasing the idle but by time the
correction kicks in the engine is already past that cylinder and is
now firing on a better running cylinder so the correction causes an
overshoot so now the motor is running too fast so now it slows the
motor down. Now you can see why the motor seems to "hunt". There is no
way to adjust any dampening into the control loop so the "fix" is to
get all the cylinders firing as evenly as you can. Do a compression
test. Forget the actual pressure #. Just compare them to each other
and if they are not within 5% you will have trouble getting the engine
to idle smooth. Next, clean and regap the spark plugs very carefully
so they are all the same. Clean the fuel injectors and replace the
seals. If it won't idle any better look for a vacuum leak, like the
"O" rings on the intake manifold to the head or the "O" ring under the
mixture unit to the cold start valve. It is also possible the idle
motor "sticks" and is not responding fast enough to the ECU. In this
case trying someone else's might prove that out. I know it is possible
for the idle ECU to go bad but it is a low failure rate item. A lot
more likely to find a bad ignition wire, a miss-gapped sprk plug, or
dirty fuel injectors.
David Teitelbaum
vin 10757






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Message: 6
Date: Sun, 24 Oct 2004 07:50:36 -0500
From: Bob Brandys <BobB_at_dml_safety-epa.com>
Subject: Re: Brake Problem


David,

Your story is similar to a problem I have experience on my other older 
cars.   THe from brake lines deteriorate internally and cause all kinds 
of weird problems.

these include.

1. The randomly sticking brake caliper.
2. Expanding hoses that make it seem like the master cylinder has failed.
3. Very soft brake pedal
4. Self adjusters in the rear that don't work.

I really have not found an simple diagnostic to identify this problem 
 other than age.  I have considered installing steel braided lines but 
won't know if they work better for another 30 years. !!

BOB






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