Audi 80 splutters after cold start?
#21
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
On 13 Aug, 10:51, "Tim.." <the.farm...@spam.btinternet.com> wrote:
> "Redwood" <n...@home.net> wrote in message
> Thermo time switch will only apply power to the cold start injector under
> about 7 deg C.
>
> Tim.
> .
My 5th injector is controlled both by a thermo switch and by the ECU
on cold start for warm-up enrichment. But since the OP said he doesnt
have a 5th inj. I guess it makes no odds.
> "Redwood" <n...@home.net> wrote in message
> Thermo time switch will only apply power to the cold start injector under
> about 7 deg C.
>
> Tim.
> .
My 5th injector is controlled both by a thermo switch and by the ECU
on cold start for warm-up enrichment. But since the OP said he doesnt
have a 5th inj. I guess it makes no odds.
#22
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
OK the cold start injector is either not there or very hidden, but I think
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
#23
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
OK the cold start injector is either not there or very hidden, but I think
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
#24
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
OK the cold start injector is either not there or very hidden, but I think
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
#25
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
OK the cold start injector is either not there or very hidden, but I think
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
the engine starts fine.
I also understand that the engine runs fine after it warms up.
Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump off
= 02 power off. Not sure on this though!
Now the engine could be running either very lean or very rich and a quick
smell of the exhaust will tell you if it is running rich when you first
start it. If it is rich then it could have a weak spark and the plugs are
fouling out.
When it is at normal operating temperature has the CO been adjusted?
You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see if
that makes a difference.
I still think it could be a vacuum leak(s) at the intake manifold boot or
the injector seals which would cause a lean condition until the rubber warms
up and expands.
Now I did not mention that the timing could be off too. Timing belt and/or
ignition.
I guess I would start at the basics and check the timing belt, ignition
components including distributor timing, fuel delivery, etc.
Did you do the major engine service?
--
later,
dave
(One out of many daves)
#26
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
"dave AKA vwdoc1" <vwdoc1@hotmail.com> wrote in message
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
#27
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
"dave AKA vwdoc1" <vwdoc1@hotmail.com> wrote in message
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
#28
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
"dave AKA vwdoc1" <vwdoc1@hotmail.com> wrote in message
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
#29
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
"dave AKA vwdoc1" <vwdoc1@hotmail.com> wrote in message
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
news:AVXvi.414$Oo.179@newssvr17.news.prodigy.net.. .
> OK the cold start injector is either not there or very hidden, but I think
> the engine starts fine.
> I also understand that the engine runs fine after it warms up.
>
> Power to the 02 sensor might be from the fuel pump circuit. Fuel Pump
> off = 02 power off. Not sure on this though!
>
> Now the engine could be running either very lean or very rich and a quick
> smell of the exhaust will tell you if it is running rich when you first
> start it. If it is rich then it could have a weak spark and the plugs are
> fouling out.
> When it is at normal operating temperature has the CO been adjusted?
> You could try adjusting the CO bolt 1/2 turn CW to richen mixture and see
> if that makes a difference.
>
> I still think it could be a vacuum leak(s) at the intake manifold boot or
> the injector seals which would cause a lean condition until the rubber
> warms up and expands.
>
> Now I did not mention that the timing could be off too. Timing belt
> and/or ignition.
> I guess I would start at the basics and check the timing belt, ignition
> components including distributor timing, fuel delivery, etc.
>
> Did you do the major engine service?
The local garage who are generally very good did the yearly service
(filters, oil & plugs) but I also replaced the dis cap & rotor arm and a
bottle of petrol treatment in the tank. I saw the old plugs and they all
look ok with no obvious signs of incorect mixture and it also passed it's
yearly MoT emissions test with no problem. I think CO is all
controlled by the ecu. Owner says it drives smoother but still has that
initial hickup from a cold start. I'm tending to lean towards no power
going to the inlet manifold pre-heater being the problem. Here's a pic I
found on a German parts site: http://tinyurl.com/3bql9w
I found this posted in reply to someone with a similar inlet pre-heater on
their VW fitted with carburettor & manual choke.
"...The 'hedgehog' as it is affectionately known prevent vaporised fuel from
condensing on the inside of the inlet manifold at low temperatures. This
reduces the amount of choke needed, improves emissions and gives better
drivability when the engine is cold..."
The Audi has SPi and no choke but if the inlet heater works on the same
principle could this be the cause of the stumble on cold starts?
#30
Guest
Posts: n/a
Re: Audi 80 splutters after cold start?
"Redwood" <not@home.net> wrote in message
news:5iaq4kF3oenuvU1@mid.individual.net...
> "Tim.." <the.farm.no@spam.btinternet.com> wrote in message
> news:ZsydnaHOq61Ft13bRVnygAA@bt.com...
>>
>> "Redwood" <not@home.net> wrote in message
>> news:5ianguF3omc0kU1@mid.individual.net...
>>> "dave AKA vwdoc1" <vwdoc1@hotmail.com> wrote in message
>>> news:ghGvi.309$%Y7.74@nlpi069.nbdc.sbc.com...
>>>> Coolant Temperature Sensor for the Fuel Injection
>>>> Loose clamps on the Intake Manifold Boot.
>>>> Bad Fuel Injector Seals allowing air by them until they warm up and
>>>> expand.
>>>> Possibly a fuel pressure problem.
>>>> To name a few possibilities.
>>>>
>>>> Did it have this problem BEFORE the full service?
>>>
>>> Thanks Dave, yes according to the owner it has been a bit stuttery on
>>> initial start off for some time. I checked the ecu temp sensor which is
>>> giving normal readings (300ohm hot & 3000 cold) But I did notice there
>>> is no voltage at the Inlet manifold heater terminal. Can anyone confirm
>>> if this should show battery voltage on ignition? I'm not sure how this
>>> operates, if it only comes on under a certain temp or should be on
>>> permanently.
>>
>> Thermo time switch will only apply power to the cold start injector under
>> about 7 deg C.
>
> I'm not sure this baby has a cold start injector, in fact it doesn't seem
> to have much at all compared to engine pics I've seen of other Audi 80's.
> It's the 2.0 SPI Mono-Motronic and it all seems very sparse underneath.
> I've now had a look on Autodata and the only engine temperature related
> items I can see on this model are the coolant temp sensor (one for ecu &
> one for gauge), Intake air temp, manifold heater & O2 heater.
Ahhh, not a K /KE jet then!
Scrap all the above..
Either you have a failed intake heater, or the injector is gummy and
sticking. The latter would be my bet.
Get it in an ultrasonic bath for a good clean to start with.
Tim.
..