From: <dmcnews_at_dml_yahoogroups.com>
To: <dmcnews_at_dml_yahoogroups.com>
Subject: [DML] Digest Number 1949
Date: Saturday, April 03, 2004 3:32 PM

There are 10 messages in this issue.

Topics in this digest:

1. Re: carbon deposits in combustion chamber
From: "Dave Swingle" <swingle_at_dml_dmcnews.com>

2. Re: carbon deposits in combustion chamber
From: "content22207" <brobertson_at_dml_carolina.net>

3. Re: carbon deposits in combustion chamber
From: "David Teitelbaum" <jtrealty_at_dml_webspan.net>

4. Re: Re: sudden death
From: "Johan Anelius" <dmc_at_dml_tranceponder.se>

5. Re: sudden death (Bad Battery Ground)
From: "content22207" <brobertson_at_dml_carolina.net>

6. RE: Re: sudden death
From: "John Hervey" <john_at_dml_specialtauto.com>

7. Hit a pavement depression
From: "Roland Smith" <roland_at_dml_dnai.com>

8. Broke frequency valve line fitting
From: "supermattthehero" <supermatty_at_dml_psu.edu>

9. Questionable Optima Battery and voltage problem
From: "Palatinus, Joe" <jopalatinus_at_dml_davidson.edu>

10. Re: Re: sudden death (Bad Battery Ground)
From: Soma576_at_dml_aol.com





Message: 1
Date: Fri, 02 Apr 2004 19:27:04 -0000
From: "Dave Swingle" <swingle_at_dml_dmcnews.com>
Subject: Re: carbon deposits in combustion chamber

That's not the combustion chamber, but the backside of the intake 
valve. The buildup is, unfortunatly, pretty normal since this is a 
CIS (constant injection) engine, so fuel is coming out of the 
injectors all the time. Over time it just builds up carbon on the 
back of the valve. There's no real good way to clean it up short of 
taking the heads off the engine removing the valves. For a while when 
gasoline started having a lot of additives put in, it was fashionable 
(not necessarily on DeLoreans) to remove the intake manifold and 
blast the back of the valves via the intake port with walnut shells, 
but I've not heard of that process for a long time now.

I'd let it be, just going in there and scraping off chunks of carbon 
is likely to cause you more problems than you'll solve. This is one 
of those "they all look like that" things. 

Dave S


--- In dmcnews_at_dml_yahoogroups.com, "supermattthehero" <supermatty_at_dml_p...> 
wrote:
> Hello,
> 
> I pulled off my intake manifold last weekend to clean things up, 
and I
> sure am glad that I did.  
> 
> Anyway, getting to the point, when I pulled the fuel injectors, I 
saw
> quite a bit of carbon buildup in the combustion chamber.  I mean, I
> can clearly see a metal rod that goes through each chamber, but the
> bottom of it is really caked up with a hard black material. 




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Message: 2
Date: Fri, 02 Apr 2004 16:43:29 -0000
From: "content22207" <brobertson_at_dml_carolina.net>
Subject: Re: carbon deposits in combustion chamber

Can't see inside the combustion chambers from either an injector bung
or an intake port. Only way to see what's going on in there (short of
pulling the heads) is to examine your spark plugs.

That rod you're seeing is a valve stem.

Some discoloration of intake valves is normal from PCV and EGR (for
cars so equipped). If you see any oil on them, time for new valve
seals. Of course the valve train itself swims in oil (hopefully). But
you do need to keep it changed regularly, and ensure that PCV works
properly, otherwise crud will build up under the valve covers.

Bill Robertson
#5939

>--- In dmcnews_at_dml_yahoogroups.com, "supermattthehero" <supermatty_at_dml_p...>
wrote:
> 
> Anyway, getting to the point, when I pulled the fuel injectors, I saw
> quite a bit of carbon buildup in the combustion chamber.  I mean, I
> can clearly see a metal rod that goes through each chamber, but the
> bottom of it is really caked up with a hard black material.  Is this
> normal?  Should I try to scrub it out?  Let me say that I did not have
> any running problems with my engine before I did this, but I like to
> fix things before they break.  
> 





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Message: 3
Date: Fri, 02 Apr 2004 16:31:40 -0000
From: "David Teitelbaum" <jtrealty_at_dml_webspan.net>
Subject: Re: carbon deposits in combustion chamber

You could try a "Top End Cleaner". It is either something you add to
the gas or the better kind, if you can find it, is poured through the
intake while the motor is running. In the "good old days" before
catalytic converters we used to pour diesel fuel in the intake or
sometimes spray water in to blow out the carbon. Today with the cats
you have to be careful what you introduce into the motor so you don't
damage the cat or the O2 sensor. The ultrasonic cleaner may do a good
job on the outside of the injectors but the only way I know to clean
then inside is to use the injector tester-cleaner as shown in the
Workshop Manual. I use mineral spirits, it has the same viscosity of
fuel and dissolves the deposits.
IMHO I would leave the carbon alone, if large chunks come loose all at
once they could damage the spark plugs, plug the cat, hang up a valve,
etc. If you are running a good brand of fuel there should not be much
carbon.
David Teitelbaum
vin 10757

--- In dmcnews_at_dml_yahoogroups.com, "supermattthehero" <supermatty_at_dml_p...>
wrote:
> Hello,
> 
> I pulled off my intake manifold last weekend to clean things up, and I





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Message: 4
Date: Fri, 2 Apr 2004 17:59:40 +0200
From: "Johan Anelius" <dmc_at_dml_tranceponder.se>
Subject: Re: Re: sudden death

Hi Andy.

I think it can be that, I replaced my main GND bolt with a stainless bolt.
My tachometer was very unstable before the GND upgrade,  but now its
completely stable.
The car was also hard to start sometimes and had to be jumpstarted, but now
it's very easy to start.

The minus cable on my car goes over the right trailingarm, so it would move
in bumps and corners.

Regards
Johan
5425

----- Original Message ----- 
From: <Soma576_at_dml_aol.com>
To: <dmcnews_at_dml_yahoogroups.com>
Sent: Friday, April 02, 2004 3:47 AM
Subject: Re: [DML] Re: sudden death


> List,
>
> Today i did the following to try and fix this:
> 1. checked inertia switch again.  I removed it and found that the housing
was
> cracked so i temporarily by-passed it.
> 2. replaced fuel and ignition related fuses and put dielectric grease on
them
> 3. added 5 gallons gas.
>
> I drove about one mile before the car shut off after taking a normal
corner,
> but it immediately restarted as i coasted and turned the key.  i noticed
that
> the rest of the way home, my Tach would stutter every now and then, like
make
> a single jerking motion as if the car died for a split second.  it didn't
shut
> off the rest of the way home (another mile).
>
> I then checked my negative ground on the battery and was able to turn it
> about 3/4 of a turn.  i didn't test drive after that because it was
getting late.
> could that be the problem?
>
> any other suggestions?  ALL parts in the fuel tank are less than 2 years
old.
>
> Andy
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> To address comments privately to the moderating team, please address:
> moderators_at_dml_dmcnews.com
>
> For more info on the list, tech articles, cars for sale see
www.dmcnews.com
>
> To search the archives or view files, log in at
http://groups.yahoo.com/group/dmcnews
> Yahoo! Groups Links
>
>
>
>
>




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Message: 5
Date: Fri, 02 Apr 2004 23:11:00 -0000
From: "content22207" <brobertson_at_dml_carolina.net>
Subject: Re: sudden death (Bad Battery Ground)

Without a complete circuit all the way back to the battery, none of
your car's electricals will work. No tach. No fuel pump. No ignition.
No nothing.

Start with that cable and work backwards:
- Ensure cable clean & tight to battery
- Ensure other end of cable clean and tight to passenger TAB mount
(factory location)
- Ensure engine to frame ground strap clean & tight behind passenger
engine cradle
- Ensure all other ground locations intact (some that come immediately
to mind: driver intake rail, passenger side of radio braket, fans on
crumple extension)

Have you ever noticed both David T and I sound like broken records Re:
automotive electrical problems? That is likely to be the most common
engine problem you will ever encounter. The only time my DeLo ever put
me walking, the cause was electrical (lost ground from the fuel pump). 

Bill Robertson
#5939

>--- In dmcnews_at_dml_yahoogroups.com, Soma576_at_dml_a... wrote:
>
> I then checked my negative ground on the battery and was able to
turn it 
> about 3/4 of a turn.  i didn't test drive after that because it was
getting late.  
> could that be the problem?
> 





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Message: 6
Date: Fri, 2 Apr 2004 18:10:49 -0600
From: "John Hervey" <john_at_dml_specialtauto.com>
Subject: RE: Re: sudden death

Andy,
The fuel pump to the car is like your heart beat, If it misses a beat your
going to feel a major jerking motion. How could it miss a beat, either it
starved a sec for gas or it was shut off a second. Since the rpm relay is
the electrical safety for the system, if you have one I would replace it and
see what happens. The contacts in the relay could be burnt real bad and
losing contact or the coil could get hot and open. I have also seen the
relay loose on the PC board.
If it's ok then your loosing a hot or gnd wire somewhere to the pump since
you said your getting that jerking motion. If it just dies then that's
another problem.
John Hervey
www.specialtauto.com



-----Original Message-----
From: Soma576_at_dml_aol.com [mailto:Soma576_at_dml_aol.com]
Sent: Thursday, April 01, 2004 7:48 PM
To: dmcnews_at_dml_yahoogroups.com
Subject: Re: [DML] Re: sudden death


List,

Today i did the following to try and fix this:
1. checked inertia switch again.  I removed it and found that the housing
was
cracked so i temporarily by-passed it.
2. replaced fuel and ignition related fuses and put dielectric grease on
them
3. added 5 gallons gas.

I drove about one mile before the car shut off after taking a normal corner,
but it immediately restarted as i coasted and turned the key.  i noticed
that
the rest of the way home, my Tach would stutter every now and then, like
make
a single jerking motion as if the car died for a split second.  it didn't
shut
off the rest of the way home (another mile).

I then checked my negative ground on the battery and was able to turn it
about 3/4 of a turn.  i didn't test drive after that because it was getting
late.
could that be the problem?

any other suggestions?  ALL parts in the fuel tank are less than 2 years
old.

Andy



[Non-text portions of this message have been removed]




To address comments privately to the moderating team, please address:
moderators_at_dml_dmcnews.com

For more info on the list, tech articles, cars for sale see www.dmcnews.com

To search the archives or view files, log in at
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________________________________________________________________________


Message: 7
Date: Fri, 2 Apr 2004 22:13:54 -0800
From: "Roland Smith" <roland_at_dml_dnai.com>
Subject: Hit a pavement depression

I couldn't see the pavement depression and went over it with the left front
tire.  It really jarred the car and after the encounter, the car pulled hard
to the right.

I went around the city block in order to see what I had hit.  As I did so,
the steering returned to the normal feel and tracked straight ahead.

What happened that the steering would pull to the right and then seem to
find a correction to the problem?

Roland Smith
Oakland, California
VIN 6667





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Message: 8
Date: Sat, 03 Apr 2004 08:30:31 -0000
From: "supermattthehero" <supermatty_at_dml_psu.edu>
Subject: Broke frequency valve line fitting

While removing the frequency valve, I broke off the barb on the 
connector that threads into the top of it.  Is it possible to repair 
this without buying a new fuel line?  Is there a cross reference for 
this particular part I can get somewhere local?

thanks,
Matt
#1604




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Message: 9
Date: Fri, 2 Apr 2004 23:23:01 -0500
From: "Palatinus, Joe" <jopalatinus_at_dml_davidson.edu>
Subject: Questionable Optima Battery and voltage problem

Last Thanksgiving I installed an El-Glo dash kit (from Ryan on the list) and a new optima battery from Pep Boys
 in my daily driver.  I started driving the car and after leaving it for 3-4 days at a time the car battery would be dead, and i could only start it with a jump. I ran the car for a while to charge the battery, but this problem kept repeating. I was convinced that the problem was I had miswired the dash kit somehow and it was somehow draining the battery.  After I would run it for a while it would start right up, so I was under the impression that the battery was still good.  This problem persisted for several months, and I finally decided to take the battery in for a test.  I took the battery to Pep boys and they tested it and within 2 minutes their analyzer said battery bad.  I hadn't even had this battery for a full year!  Luckily Pep Boys exchanged the 130$ battery for free and I have had no problems starting since then.  
I have noticed however that my voltage seems to drop to exceedingly low levels randomly (lower than the first red mark).  (The battery light remains off, and the car still seems to operate fine, but I worry that this is due to the battery being fresh and new.  I have one of 105 amp delco alternators, so I wouldn't immediately suspect the alternator.  If the battery light remains off the alternator should still be ok right?  
Thanks
Joe P.
VIN 17167 6808



[Non-text portions of this message have been removed]




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Message: 10
Date: Sat, 3 Apr 2004 13:27:07 EST
From: Soma576_at_dml_aol.com
Subject: Re: Re: sudden death (Bad Battery Ground)

List,

in my investigation of this problem, i need to know where exactly the fuel 
pump ground is located, so i can check and clean it.  where do i find it?

Andy


[Non-text portions of this message have been removed]



________________________________________________________________________
________________________________________________________________________


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