[DeTomaso] Unhappy motor - looking for suggestions
jgkrenton at comcast.net
jgkrenton at comcast.net
Sun Nov 2 18:55:50 EST 2014
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
----- Original Message -----
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
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>>
>>
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>
>
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>
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>
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-------------- next part --------------
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
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