Thanks, Jim. Your suggestions sound promising.

Would high or low voltage out of the TPS trigger a trouble code? (I haven't
had one with this problem.)

The igniter also sounds like a possible answer, especially given it's
closeness to the hottest part of the engine. But replacing it will be a
$130 gamble. Is there any way to test the igniter?


"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
> Maybe you should monitor the reference voltage going to the Throttle
> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
> dropping(it's source is the ECU),or the TPS output is changing (bad
> TPS)and
> telling the ECU to lower the idle....to a point where it will not run
> properly.
> Take a "cold" reading on the reference V,then another when the engine
> starts to stumble. You'll have to backpin the connector.
>
> Or maybe the igniter (in the distributor)is the problem;perhaps altering
> the firing of the coil once it warms up.
>
> --
> Jim Yanik
> jyanik
> at
> kua.net

 

Thanks, Jim. Your suggestions sound promising.

Would high or low voltage out of the TPS trigger a trouble code? (I haven't
had one with this problem.)

The igniter also sounds like a possible answer, especially given it's
closeness to the hottest part of the engine. But replacing it will be a
$130 gamble. Is there any way to test the igniter?


"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
> Maybe you should monitor the reference voltage going to the Throttle
> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
> dropping(it's source is the ECU),or the TPS output is changing (bad
> TPS)and
> telling the ECU to lower the idle....to a point where it will not run
> properly.
> Take a "cold" reading on the reference V,then another when the engine
> starts to stumble. You'll have to backpin the connector.
>
> Or maybe the igniter (in the distributor)is the problem;perhaps altering
> the firing of the coil once it warms up.
>
> --
> Jim Yanik
> jyanik
> at
> kua.net

 

Thanks, Jim. Your suggestions sound promising.

Would high or low voltage out of the TPS trigger a trouble code? (I haven't
had one with this problem.)

The igniter also sounds like a possible answer, especially given it's
closeness to the hottest part of the engine. But replacing it will be a
$130 gamble. Is there any way to test the igniter?


"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
> Maybe you should monitor the reference voltage going to the Throttle
> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
> dropping(it's source is the ECU),or the TPS output is changing (bad
> TPS)and
> telling the ECU to lower the idle....to a point where it will not run
> properly.
> Take a "cold" reading on the reference V,then another when the engine
> starts to stumble. You'll have to backpin the connector.
>
> Or maybe the igniter (in the distributor)is the problem;perhaps altering
> the firing of the coil once it warms up.
>
> --
> Jim Yanik
> jyanik
> at
> kua.net

 

John Smith wrote:
> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I haven't
> had one with this problem.)
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be a
> $130 gamble. Is there any way to test the igniter?

yes. it's written up at tegger.com. but if the vehicle runs at all,
it's unlikely to be the igniter.

bottom line, if working on the distributor scratched the itch, and it
seems to have, keep poking about with that. suggest removal, cleaning,
and thorough inspection. read all of tegger's write-ups on ignition
problems.

also, make sure you use denso or ngk plugs.

>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps altering
>> the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>

 

John Smith wrote:
> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I haven't
> had one with this problem.)
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be a
> $130 gamble. Is there any way to test the igniter?

yes. it's written up at tegger.com. but if the vehicle runs at all,
it's unlikely to be the igniter.

bottom line, if working on the distributor scratched the itch, and it
seems to have, keep poking about with that. suggest removal, cleaning,
and thorough inspection. read all of tegger's write-ups on ignition
problems.

also, make sure you use denso or ngk plugs.

>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps altering
>> the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>

 

John Smith wrote:
> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I haven't
> had one with this problem.)
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be a
> $130 gamble. Is there any way to test the igniter?

yes. it's written up at tegger.com. but if the vehicle runs at all,
it's unlikely to be the igniter.

bottom line, if working on the distributor scratched the itch, and it
seems to have, keep poking about with that. suggest removal, cleaning,
and thorough inspection. read all of tegger's write-ups on ignition
problems.

also, make sure you use denso or ngk plugs.

>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps altering
>> the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>

 

"John Smith" <jsmith@yahoo.com> wrote in
news:Pcici.55$Hl2.23@newsfe12.lga:

> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I
> haven't had one with this problem.)

the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
Reference input V went high(more than 5V),I suppose that could "set a
code",but I doubt it.
A code is probably generated if there's NO output V from the TPS.
Like if the ref V input failed or the TPS went open.

If anyone knew the value of the variable resistor in the TPS,one could sub
a pot for it and see if that fixed(steadied) the idle.
Maybe a 10K or 50K linear pot.
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be
> a $130 gamble. Is there any way to test the igniter?

Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
or erratic.
Since most people don't have those instruments,the only other way is to
swap it out with a good one.
>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps
>> altering the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>
>



--
Jim Yanik
jyanik
at
kua.net

 

"John Smith" <jsmith@yahoo.com> wrote in
news:Pcici.55$Hl2.23@newsfe12.lga:

> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I
> haven't had one with this problem.)

the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
Reference input V went high(more than 5V),I suppose that could "set a
code",but I doubt it.
A code is probably generated if there's NO output V from the TPS.
Like if the ref V input failed or the TPS went open.

If anyone knew the value of the variable resistor in the TPS,one could sub
a pot for it and see if that fixed(steadied) the idle.
Maybe a 10K or 50K linear pot.
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be
> a $130 gamble. Is there any way to test the igniter?

Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
or erratic.
Since most people don't have those instruments,the only other way is to
swap it out with a good one.
>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps
>> altering the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>
>



--
Jim Yanik
jyanik
at
kua.net

 

"John Smith" <jsmith@yahoo.com> wrote in
news:Pcici.55$Hl2.23@newsfe12.lga:

> Thanks, Jim. Your suggestions sound promising.
>
> Would high or low voltage out of the TPS trigger a trouble code? (I
> haven't had one with this problem.)

the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
Reference input V went high(more than 5V),I suppose that could "set a
code",but I doubt it.
A code is probably generated if there's NO output V from the TPS.
Like if the ref V input failed or the TPS went open.

If anyone knew the value of the variable resistor in the TPS,one could sub
a pot for it and see if that fixed(steadied) the idle.
Maybe a 10K or 50K linear pot.
>
> The igniter also sounds like a possible answer, especially given it's
> closeness to the hottest part of the engine. But replacing it will be
> a $130 gamble. Is there any way to test the igniter?

Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
or erratic.
Since most people don't have those instruments,the only other way is to
swap it out with a good one.
>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>> Maybe you should monitor the reference voltage going to the Throttle
>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>> dropping(it's source is the ECU),or the TPS output is changing (bad
>> TPS)and
>> telling the ECU to lower the idle....to a point where it will not run
>> properly.
>> Take a "cold" reading on the reference V,then another when the engine
>> starts to stumble. You'll have to backpin the connector.
>>
>> Or maybe the igniter (in the distributor)is the problem;perhaps
>> altering the firing of the coil once it warms up.
>>
>> --
>> Jim Yanik
>> jyanik
>> at
>> kua.net
>
>
>



--
Jim Yanik
jyanik
at
kua.net

 

jim beam <spamvortex@bad.example.net> wrote in
news:IvGdnS-fANS3Y-zbnZ2dnUVZ_vjinZ2d@speakeasy.net:

> John Smith wrote:
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>>
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will
>> be a $130 gamble. Is there any way to test the igniter?
>
> yes. it's written up at tegger.com. but if the vehicle runs at all,
> it's unlikely to be the igniter.

there's an IC and a switching transistor in there that could be affected by
heat or temperature sensitive.IIRC,there's white heat sink grease used to
help heat transfer from the ceramic substrate of the igniter to the metal
of the distributor.maybe that grease is missing?

>
> bottom line, if working on the distributor scratched the itch, and it
> seems to have, keep poking about with that. suggest removal,
> cleaning, and thorough inspection. read all of tegger's write-ups on
> ignition problems.
>
> also, make sure you use denso or ngk plugs.

Someone else mentioned using only OEM Honda distributor cap/coil and
rotor,that aftermarket parts caused him a lot of wacky trouble.

>
>>
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not
>>> run properly.
>>> Take a "cold" reading on the reference V,then another when the
>>> engine starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
>



--
Jim Yanik
jyanik
at
kua.net

 

jim beam <spamvortex@bad.example.net> wrote in
news:IvGdnS-fANS3Y-zbnZ2dnUVZ_vjinZ2d@speakeasy.net:

> John Smith wrote:
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>>
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will
>> be a $130 gamble. Is there any way to test the igniter?
>
> yes. it's written up at tegger.com. but if the vehicle runs at all,
> it's unlikely to be the igniter.

there's an IC and a switching transistor in there that could be affected by
heat or temperature sensitive.IIRC,there's white heat sink grease used to
help heat transfer from the ceramic substrate of the igniter to the metal
of the distributor.maybe that grease is missing?

>
> bottom line, if working on the distributor scratched the itch, and it
> seems to have, keep poking about with that. suggest removal,
> cleaning, and thorough inspection. read all of tegger's write-ups on
> ignition problems.
>
> also, make sure you use denso or ngk plugs.

Someone else mentioned using only OEM Honda distributor cap/coil and
rotor,that aftermarket parts caused him a lot of wacky trouble.

>
>>
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not
>>> run properly.
>>> Take a "cold" reading on the reference V,then another when the
>>> engine starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
>



--
Jim Yanik
jyanik
at
kua.net

 

jim beam <spamvortex@bad.example.net> wrote in
news:IvGdnS-fANS3Y-zbnZ2dnUVZ_vjinZ2d@speakeasy.net:

> John Smith wrote:
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>>
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will
>> be a $130 gamble. Is there any way to test the igniter?
>
> yes. it's written up at tegger.com. but if the vehicle runs at all,
> it's unlikely to be the igniter.

there's an IC and a switching transistor in there that could be affected by
heat or temperature sensitive.IIRC,there's white heat sink grease used to
help heat transfer from the ceramic substrate of the igniter to the metal
of the distributor.maybe that grease is missing?

>
> bottom line, if working on the distributor scratched the itch, and it
> seems to have, keep poking about with that. suggest removal,
> cleaning, and thorough inspection. read all of tegger's write-ups on
> ignition problems.
>
> also, make sure you use denso or ngk plugs.

Someone else mentioned using only OEM Honda distributor cap/coil and
rotor,that aftermarket parts caused him a lot of wacky trouble.

>
>>
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not
>>> run properly.
>>> Take a "cold" reading on the reference V,then another when the
>>> engine starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
>



--
Jim Yanik
jyanik
at
kua.net

 

Jim Yanik wrote:
> "John Smith" <jsmith@yahoo.com> wrote in
> news:Pcici.55$Hl2.23@newsfe12.lga:
>
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>
> the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
> Reference input V went high(more than 5V),I suppose that could "set a
> code",but I doubt it.
> A code is probably generated if there's NO output V from the TPS.
> Like if the ref V input failed or the TPS went open.
>
> If anyone knew the value of the variable resistor in the TPS,one could sub
> a pot for it and see if that fixed(steadied) the idle.
> Maybe a 10K or 50K linear pot.
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will be
>> a $130 gamble. Is there any way to test the igniter?
>
> Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
> or erratic.

if it is, it's unlikely to be the igniter. the igniter's just an
electronic power switch. like most other semicons, they usually either
work, or they don't.

kinda related to this, i'm a big fan of premium coiled core spark plug
leads. they suppress a lot electrical noise under the hood that the
rubber core leads don't. this means less noise for the sensor inputs to
filter and i think it makes the vehicle run much more smoothly all ways
around.


> Since most people don't have those instruments,the only other way is to
> swap it out with a good one.
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not run
>>> properly.
>>> Take a "cold" reading on the reference V,then another when the engine
>>> starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
>
>
>

 

Jim Yanik wrote:
> "John Smith" <jsmith@yahoo.com> wrote in
> news:Pcici.55$Hl2.23@newsfe12.lga:
>
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>
> the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
> Reference input V went high(more than 5V),I suppose that could "set a
> code",but I doubt it.
> A code is probably generated if there's NO output V from the TPS.
> Like if the ref V input failed or the TPS went open.
>
> If anyone knew the value of the variable resistor in the TPS,one could sub
> a pot for it and see if that fixed(steadied) the idle.
> Maybe a 10K or 50K linear pot.
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will be
>> a $130 gamble. Is there any way to test the igniter?
>
> Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
> or erratic.

if it is, it's unlikely to be the igniter. the igniter's just an
electronic power switch. like most other semicons, they usually either
work, or they don't.

kinda related to this, i'm a big fan of premium coiled core spark plug
leads. they suppress a lot electrical noise under the hood that the
rubber core leads don't. this means less noise for the sensor inputs to
filter and i think it makes the vehicle run much more smoothly all ways
around.


> Since most people don't have those instruments,the only other way is to
> swap it out with a good one.
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not run
>>> properly.
>>> Take a "cold" reading on the reference V,then another when the engine
>>> starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
>
>
>

 

Jim Yanik wrote:
> "John Smith" <jsmith@yahoo.com> wrote in
> news:Pcici.55$Hl2.23@newsfe12.lga:
>
>> Thanks, Jim. Your suggestions sound promising.
>>
>> Would high or low voltage out of the TPS trigger a trouble code? (I
>> haven't had one with this problem.)
>
> the OUTPUT is supposed to vary with throttle position,0-~4.5V.If the
> Reference input V went high(more than 5V),I suppose that could "set a
> code",but I doubt it.
> A code is probably generated if there's NO output V from the TPS.
> Like if the ref V input failed or the TPS went open.
>
> If anyone knew the value of the variable resistor in the TPS,one could sub
> a pot for it and see if that fixed(steadied) the idle.
> Maybe a 10K or 50K linear pot.
>> The igniter also sounds like a possible answer, especially given it's
>> closeness to the hottest part of the engine. But replacing it will be
>> a $130 gamble. Is there any way to test the igniter?
>
> Scope it's output,with an oscilloscope. See if the pulse train is too jumpy
> or erratic.

if it is, it's unlikely to be the igniter. the igniter's just an
electronic power switch. like most other semicons, they usually either
work, or they don't.

kinda related to this, i'm a big fan of premium coiled core spark plug
leads. they suppress a lot electrical noise under the hood that the
rubber core leads don't. this means less noise for the sensor inputs to
filter and i think it makes the vehicle run much more smoothly all ways
around.


> Since most people don't have those instruments,the only other way is to
> swap it out with a good one.
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns994E84BB4278Djyanikkuanet@64.209.0.87...
>>> Maybe you should monitor the reference voltage going to the Throttle
>>> Position Sensor(TPS)and the TPS output voltage.Perhaps the ref V is
>>> dropping(it's source is the ECU),or the TPS output is changing (bad
>>> TPS)and
>>> telling the ECU to lower the idle....to a point where it will not run
>>> properly.
>>> Take a "cold" reading on the reference V,then another when the engine
>>> starts to stumble. You'll have to backpin the connector.
>>>
>>> Or maybe the igniter (in the distributor)is the problem;perhaps
>>> altering the firing of the coil once it warms up.
>>>
>>> --
>>> Jim Yanik
>>> jyanik
>>> at
>>> kua.net
>>
>>
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