[DeTomaso] Unhappy motor - looking for suggestions
Charles McCall
charlesmccall at gmail.com
Mon Nov 3 08:48:02 EST 2014
Thanks Jeff. It isn't unusually humid here and the car is always stored
indoors. As I was writing this, however, it occured to me that it isn't
imposible that some wáter may have entered the air cleaner and dropped into
the carb while washing the car. I'm usually pretty careful with where I aim
the hose, but I couldn't swear that the engine stayed dry, or when opening
the decklid when wet, some wáter may have run off near the cleaner...
I will take the air cleaner off and see if I see a healthy squirt from the
acclerator pump. I don't think it would be fuel pump or clogged fuel
filter, as it stumbles under trailing throttle as well, it it can provide
enough fuel for sustainted 115mph running
Could it be electrical? My last MSD 6AL gave some really weird symptoms
that I thought were carb-related before I changed the box and all my
problems went away. I'll go step-by-step
On Mon, Nov 3, 2014 at 12:55 AM, <jgkrenton at comcast.net> wrote:
> Charlie:
>
> How's the weather??
>
> Your problem sort of sounds like it could be water in the fuel to me.
> Just a drop can be a problem and once you get it in there, it can hang
> around a long time.
>
> As already mentioned, do the usual things to make sure you didn't
> "introduce" the problem during the recent tuning. Take the air cleaner off
> and see if that makes any difference. Check the timing (yes, a pain on the
> Pantera). Make sure the accelerator pump is squirting. Check the fuel
> pressure/fuel pump etc. I have also been recently bit by a bad coil and a
> bad fuel pump. Don't rule anything out.
>
> Then dump some "fuel dryer" in the tank and run it a bit to see if that
> helps. Here in Seattle, water in the fuel is a common problem.
>
> The fuel dryer should help, but there is also the tried and true "rag
> tune".
>
> You have to be careful with this one, but the idea is to rev the engine a
> bit by hand with the air cleaner off. Then when the engine is reving a
> bit, maybe 2500 RPM, shove a big rag over the carb for just a second. (The
> air-horns, choke, secondary venturies will keep the rag from being sucked
> into the engine). The rag acts like a massive choke and the engine will
> smoke and die if you leave the rag there for more than a few seconds. But
> what this does is raise the full engine vacuum up above the throttle plates
> and jets/ bleeds to the air-horn/rag level. This "extra" vacuum will draw
> any water out of the jets/bleeds where the "normal" vacuum often is not
> strong enough to pull any water out of the jets.
>
> If your carb is a Holley, you can pull the float chambers off too and make
> sure they don't have water in them....
>
> Good luck.
>
> Jeff/2467
>
>
>
>
>
> ------------------------------
> *From: *"McCall, Charles" <charlesmccall at gmail.com>
> *To: *"Mark Charlton" <pantera01826 at rogers.com>
> *Cc: *"DeTomaso Mail List" <detomaso at poca.com>
> *Sent: *Sunday, November 2, 2014 11:46:48 AM
>
> *Subject: *Re: [DeTomaso] Unhappy motor - looking for suggestions
>
> Thanks Mark, but I used 3 full tanks of gas in the past 2 days :-o
>
> The problem has gotten slowly worse, I think.
>
> -----Original Message-----
> From: Mark Charlton [mailto:pantera01826 at rogers.com]
> Sent: domingo, 2 de noviembre de 2014 20:43
> To: Charles McCall
> Cc: DeTomaso Mail List
> Subject: Re: [DeTomaso] Unhappy motor - looking for suggestions
>
> Charlie,
>
> I had a very similar experience with my car during a long tour in western
> Canada. We checked everything and concluded it must be a carb issue. After
> a
> full tear-down of the carb revealed nothing wrong at all, I filled the car
> (it was 3/4 empty) and the car ran fine again. We concluded that a stale
> batch of 94 octane gas (not commonly available) caused the issue. With any
> luck that will be your case too I hope.
>
> Mark Charlton
> pantera01826 at rogers.com
>
>
>
> On Nov 2, 2014, at 2:20 PM, Charles McCall <charlesmccall at gmail.com>
> wrote:
>
> > I haven't checked timing, but wouldn't that make the engine run hot?
> >
> > Would that explain the stumble? It might explain why it doesn't feel as
> > crisp as it should
> >
> > -----Original Message-----
> > From: thomas [mailto:thomas at hax.se]
> > Sent: domingo, 2 de noviembre de 2014 20:18
> > To: Charles McCall
> > Cc: <detomaso at poca.com>
> > Subject: Re: [DeTomaso] Unhappy motor - looking for suggestions
> >
> > The distributor gear pin?
> >
> > Checked timing?
> >
> >
> >> 2 nov 2014 kl. 20:13 skrev Charles McCall <charlesmccall at gmail.com>:
> >>
> >> Hi all
> >>
> >>
> >> I just got back from a Supercar event in northern Spain with 35 cars
> >> attending - Lambo, Ferrari, Viper, Porsche, and, as usual, a lone
> >> DeTomaso!
> >>
> >>
> >> The highlight for me without a doubt was an 8-minute burst on the
> >> highway with the police clearing the way for us, cruising at a steady
> >> GPS-indicated 180 k/hr in a 35 car convoy... the people out for a
> >> Sunday drive must have had their minds boggled...
> >>
> >>
> >> Anyway, my engine is not happy. This morning in the hotel parking lot I
> >> really thought that we'd have to skip today's event because it wouldn't
> >> start and didn't sound like it was even thinking about starting. Took
> >> probably 5 minutes of crank-wait-crank-wait before it fired. Yesterday
> >> at the gas station it took 2-3 minutes to start, something that has
> >> never, ever happened before. It is really hard to describe the problem
> >> so much of it is "feel", but I'll do my best.
> >>
> >>
> >> A few weeks ago I noticed that the engine would tend to stumble if I
> >> would floor the throttle, then clear its throat and pull. For example,
> >> I like to heel-and-toe, just because, and when blipping the throttle it
> >> would stumble instead of rev. The engine also felt a little rougher, as
> >> though it vibrated more than I remembered it. I don't remember if this
> >> was before or after I did a short tune-up, by adjusting the valve lash
> >> (I have mechanical lifters), and cleaning the K&N air filter by
> >> applying K&N filter oil, etc. or if it is irrelevant. So I was messing
> >> around in the engine bay recently...
> >>
> >>
> >> This weekend the engine felt considerably worse. It felt like it would
> >> stumble under partial throttle as well. It would stumble a little bit
> >> under trailing throttle going downhill as well, so I don't think it is
> >> a clogged fuel filter.
> >>
> >>
> >> Oil temp is perfect. Oil pressure is perfect. Water temp is perfect.
> >> The engine idles perfectly. But if you floor the gas from idle, it'll
> >> stall. The engine doesn't feel crisp, it feels bloated and soft, if
> >> that makes sense. It feels rough, and it feels like it occasionally
> >> stumbles under constant throttle at highway speed. It pulls hard when
> >> accelerating, but I don't think as hard as it used to, or as high (I
> >> have a 6500 rpm limiting chip in the MSD that it used to pull very
> >> easily to).
> >>
> >>
> >> Suggestions for where to begin looking? And other info that would help
> >> in troubleshooting?
> >>
> >>
> >> !DSPAM:54568258260291209923907!
> >> _______________________________________________
> >>
> >> Detomaso Forum Managed by POCA
> >>
> >> DeTomaso mailing list
> >> DeTomaso at poca.com
> >> http://poca.com/mailman/listinfo/detomaso_poca.com
> >>
> >>
> >> !DSPAM:54568258260291209923907!
> >
> >
> > _______________________________________________
> >
> > Detomaso Forum Managed by POCA
> >
> > DeTomaso mailing list
> > DeTomaso at poca.com
> > http://poca.com/mailman/listinfo/detomaso_poca.com
>
>
>
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> DeTomaso mailing list
> DeTomaso at poca.com
> http://poca.com/mailman/listinfo/detomaso_poca.com
>
>
-------------- next part --------------
Thanks Jeff. It isn't unusually humid here and the car is always stored
indoors. As I was writing this, however, it occured to me that it isn't
imposible that some wA!ter may have entered the air cleaner and dropped
into the carb while washing the car. I'm usually pretty careful with
where I aim the hose, but I couldn't swear that the engine stayed dry,
or when opening the decklid when wet, some wA!ter may have run off near
the cleaner...
A
I will take the air cleaner off and see if I see a healthy squirt from
the acclerator pump. I don't think it would be fuel pump or clogged
fuel filter, as it stumbles under trailing throttle as well, it it can
provide enough fuel for sustainted 115mph running
A
Could it be electrical? My last MSD 6AL gave some really weird symptoms
that I thought were carb-related before I changed the box and all my
problems went away. I'll go step-by-step
On Mon, Nov 3, 2014 at 12:55 AM, <[1]jgkrenton at comcast.net> wrote:
Charlie:
How's the weather??
Your problem sort of sounds like it could be water in the fuel to me.A
Just a drop can be a problem and once you get it in there, it can hang
around a long time.A
As already mentioned, do the usual things to make sure you didn't
"introduce" the problem during the recent tuning.A Take the air
cleaner off and see if that makes any difference.A Check the timing
(yes, a pain on the Pantera). Make sure the accelerator pump is
squirting. Check the fuel pressure/fuel pump etc.A I have also been
recently bit by a bad coil and a bad fuel pump.A Don't rule anything
out.
Then dump some "fuel dryer" in the tank and run it a bit to see if that
helps.A Here in Seattle, water in the fuel is a common problem.
The fuel dryer should help, but there is also the tried and true "rag
tune".
You have to be careful with this one, but the idea is to rev the engine
a bit by hand with the air cleaner off.A A Then when the engine is
reving a bit, maybe 2500 RPM, shove a big rag over the carb for just a
second. (The air-horns, choke, secondary venturies will keep the rag
from being sucked into the engine). The rag acts like a massive choke
and the engine will smoke and die if you leave the rag there for more
than a few seconds.A But what this does is raise the full engine
vacuum up above the throttle plates and jets/ bleeds to the
air-horn/rag level.A This "extra" vacuum will draw any water out of
the jets/bleeds where the "normal" vacuum often is not strong enough to
pull any water out of the jets.
If your carb is a Holley, you can pull the float chambers off too and
make sure they don't have water in them....
Good luck.
Jeff/2467
__________________________________________________________________
From: "McCall, Charles" <[2]charlesmccall at gmail.com>
To: "Mark Charlton" <[3]pantera01826 at rogers.com>
Cc: "DeTomaso Mail List" <[4]detomaso at poca.com>
Sent: Sunday, November 2, 2014 11:46:48 AM
Subject: Re: [DeTomaso] Unhappy motor - looking for suggestions
Thanks Mark, but I used 3 full tanks of gas in the past 2 days :-o
The problem has gotten slowly worse, I think.
-----Original Message-----
From: Mark Charlton [mailto:[5]pantera01826 at rogers.com]
Sent: domingo, 2 de noviembre de 2014 20:43
To: Charles McCall
Cc: DeTomaso Mail List
Subject: Re: [DeTomaso] Unhappy motor - looking for suggestions
Charlie,
I had a very similar experience with my car during a long tour in
western
Canada. We checked everything and concluded it must be a carb issue.
After a
full tear-down of the carb revealed nothing wrong at all, I filled the
car
(it was 3/4 empty) and the car ran fine again. We concluded that a
stale
batch of 94 octane gas (not commonly available) caused the issue. With
any
luck that will be your case too I hope.
Mark Charlton
[6]pantera01826 at rogers.com
On Nov 2, 2014, at 2:20 PM, Charles McCall <[7]charlesmccall at gmail.com>
wrote:
> I haven't checked timing, but wouldn't that make the engine run hot?
>
> Would that explain the stumble? It might explain why it doesn't feel
as
> crisp as it should
>
> -----Original Message-----
> From: thomas [mailto:[8]thomas at hax.se]
> Sent: domingo, 2 de noviembre de 2014 20:18
> To: Charles McCall
> Cc: <[9]detomaso at poca.com>
> Subject: Re: [DeTomaso] Unhappy motor - looking for suggestions
>
> The distributor gear pin?
>
> Checked timing?
>
>
>> 2 nov 2014 kl. 20:13 skrev Charles McCall
<[10]charlesmccall at gmail.com>:
>>
>> A Hi all
>>
>>
>> A I just got back from a Supercar event in northern Spain with 35
cars
>> A attending - Lambo, Ferrari, Viper, Porsche, and, as usual, a lone
>> A DeTomaso!
>>
>>
>> A The highlight for me without a doubt was an 8-minute burst on the
>> A highway with the police clearing the way for us, cruising at a
steady
>> A GPS-indicated 180 k/hr in a 35 car convoy... the people out for a
>> A Sunday drive must have had their minds boggled...
>>
>>
>> A Anyway, my engine is not happy. This morning in the hotel parking
lot I
>> A really thought that we'd have to skip today's event because it
wouldn't
>> A start and didn't sound like it was even thinking about starting.
Took
>> A probably 5 minutes of crank-wait-crank-wait before it fired.
Yesterday
>> A at the gas station it took 2-3 minutes to start, something that
has
>> A never, ever happened before. It is really hard to describe the
problem
>> A so much of it is "feel", but I'll do my best.
>>
>>
>> A A few weeks ago I noticed that the engine would tend to stumble if
I
>> A would floor the throttle, then clear its throat and pull. For
example,
>> A I like to heel-and-toe, just because, and when blipping the
throttle it
>> A would stumble instead of rev. The engine also felt a little
rougher, as
>> A though it vibrated more than I remembered it. I don't remember if
this
>> A was before or after I did a short tune-up, by adjusting the valve
lash
>> A (I have mechanical lifters), and cleaning the K&N air filter by
>> A applying K&N filter oil, etc. or if it is irrelevant. So I was
messing
>> A around in the engine bay recently...
>>
>>
>> A This weekend the engine felt considerably worse. It felt like it
would
>> A stumble under partial throttle as well. It would stumble a little
bit
>> A under trailing throttle going downhill as well, so I don't think
it is
>> A a clogged fuel filter.
>>
>>
>> A Oil temp is perfect. Oil pressure is perfect. Water temp is
perfect.
>> A The engine idles perfectly. But if you floor the gas from idle,
it'll
>> A stall. The engine doesn't feel crisp, it feels bloated and soft,
if
>> A that makes sense. It feels rough, and it feels like it
occasionally
>> A stumbles under constant throttle at highway speed. It pulls hard
when
>> A accelerating, but I don't think as hard as it used to, or as high
(I
>> A have a 6500 rpm limiting chip in the MSD that it used to pull very
>> A easily to).
>>
>>
>> A Suggestions for where to begin looking? And other info that would
help
>> A in troubleshooting?
>>
>>
>> !DSPAM:54568258260291209923907!
>> _______________________________________________
>>
>> Detomaso Forum Managed by POCA
>>
>> DeTomaso mailing list
>> [11]DeTomaso at poca.com
>> [12]http://poca.com/mailman/listinfo/detomaso_poca.com
>>
>>
>> !DSPAM:54568258260291209923907!
>
>
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> DeTomaso mailing list
> [13]DeTomaso at poca.com
> [14]http://poca.com/mailman/listinfo/detomaso_poca.com
_______________________________________________
Detomaso Forum Managed by POCA
DeTomaso mailing list
[15]DeTomaso at poca.com
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References
1. mailto:jgkrenton at comcast.net
2. mailto:charlesmccall at gmail.com
3. mailto:pantera01826 at rogers.com
4. mailto:detomaso at poca.com
5. mailto:pantera01826 at rogers.com
6. mailto:pantera01826 at rogers.com
7. mailto:charlesmccall at gmail.com
8. mailto:thomas at hax.se
9. mailto:detomaso at poca.com
10. mailto:charlesmccall at gmail.com
11. mailto:DeTomaso at poca.com
12. http://poca.com/mailman/listinfo/detomaso_poca.com
13. mailto:DeTomaso at poca.com
14. http://poca.com/mailman/listinfo/detomaso_poca.com
15. mailto:DeTomaso at poca.com
16. http://poca.com/mailman/listinfo/detomaso_poca.com
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