84 VW Rabbit GTI - Hard to start when hot

Replace the fuel accumulator (near the fuel pump by the tank). The
accumulator holds pressure in the system and prevents vapor lock.

"SFC" <SF-CILLARI.DeleteThis@HETNET.NL> wrote in message
news:44f80c30$0$2014$ba620dc5@text.nova.planet.nl...
> Again a typical case of vapour lock. Fuel pressure drops off too quickly.
> The fuel system should hold the pressure (about 14psi) for at least
> 20..30min. Check for leaks and if it's a cis injection replace the o-rings
> of the fuel pressure regulator located in the fuel distributor.
>
> SFC
>
> "JH" <zrt_100100.DeleteThis@yahoo.com> schreef in bericht
> news:1156978519.182771.163680@p79g2000cwp.googlegroups.com...
>> Regarding my recently aquired 84 VW Rabbit GTI - manual trans - 8
>> valve.
>>
>> I have read posts regarding topics relating to hard, hot starts but
>> have some additional questions.
>>
>> The car starts fine when it's completely cold, but takes quite a lot of
>> cranking in order to get it to start when the engine is hot. I checked
>> the cold start injector and found that it is working as it should on a
>> cold start (sprays for about 8 seconds, then stops). However, the cold
>> start injector does not operate at all on a hot start. The car does a
>> "hot start" when I manually put 12 volts to the cold start injector for
>> a few seconds while a helper starts the car.
>>
>> The other posts suggest that the failure is in the "hot start relay".
>> I can not find a hot start relay on the car, or referenced as a part
>> for this car. The only thing close is the CIS/Lambda relay. Is that
>> it?
>>
>> I am about ready to add 12 volts directly to the cold start injector
>> via a switch or, timer relay.
>>
>> Any suggestions?
>>
>> Thank you in advance!
>>
>> Jeff
>>
>
>
 >> Stay informed about: 84 VW Rabbit GTI - Hard to start when hot 

TEST TEST TEST
It is best to purchase some tools to monitor fuel pressure
Before just throwing parts at your problem, unless price is no object.

So many items could cause your problem and it could cost you over $600 just
in parts with injectors, fuel distributor, fuel pump or it's check valve or
relay, fuel accumulator, plus whatever else I have forgotten about like
slightly leaking fuel lines.
I had to do this with a Scirocco saved from the junkyard and it needed
almost everything. Started up instantly at all times though.
--
JMHO
later,
dave
(One out of many daves)

"Erik Dillenkofer" <lifeguard1974.RemoveThis@hotmail.com> wrote in message
news:9YGdndvOOO160WTZnZ2dnUVZ_radnZ2d@adelphia.com...
> Replace the fuel accumulator (near the fuel pump by the tank). The
> accumulator holds pressure in the system and prevents vapor lock.
>
> "SFC" <SF-CILLARI.RemoveThis@HETNET.NL> wrote in message
> news:44f80c30$0$2014$ba620dc5@text.nova.planet.nl...
>> Again a typical case of vapour lock. Fuel pressure drops off too quickly.
>> The fuel system should hold the pressure (about 14psi) for at least
>> 20..30min. Check for leaks and if it's a cis injection replace the
>> o-rings of the fuel pressure regulator located in the fuel distributor.
>>
>> SFC
>>
>> "JH" <zrt_100100.RemoveThis@yahoo.com> schreef in bericht
>> news:1156978519.182771.163680@p79g2000cwp.googlegroups.com...
>>> Regarding my recently aquired 84 VW Rabbit GTI - manual trans - 8
>>> valve.
>>>
>>> I have read posts regarding topics relating to hard, hot starts but
>>> have some additional questions.
>>>
>>> The car starts fine when it's completely cold, but takes quite a lot of
>>> cranking in order to get it to start when the engine is hot. I checked
>>> the cold start injector and found that it is working as it should on a
>>> cold start (sprays for about 8 seconds, then stops). However, the cold
>>> start injector does not operate at all on a hot start. The car does a
>>> "hot start" when I manually put 12 volts to the cold start injector for
>>> a few seconds while a helper starts the car.
>>>
>>> The other posts suggest that the failure is in the "hot start relay".
>>> I can not find a hot start relay on the car, or referenced as a part
>>> for this car. The only thing close is the CIS/Lambda relay. Is that
>>> it?
>>>
>>> I am about ready to add 12 volts directly to the cold start injector
>>> via a switch or, timer relay.
>>>
>>> Any suggestions?
>>>
>>> Thank you in advance!
>>>
>>> Jeff
>>>
>>
>>
>
>
 >> Stay informed about: 84 VW Rabbit GTI - Hard to start when hot 

I think a different control pressure regulator fixed the problem in my
84 GTI. Test pressure guage was not reading correctly.

On 30 Aug 2006 15:55:19 -0700, "JH" <zrt_100100 DeleteThis @yahoo.com> wrote:

>Regarding my recently aquired 84 VW Rabbit GTI - manual trans - 8
>valve.
>
>I have read posts regarding topics relating to hard, hot starts but
>have some additional questions.
>
>The car starts fine when it's completely cold, but takes quite a lot of
>cranking in order to get it to start when the engine is hot. I checked
>the cold start injector and found that it is working as it should on a
>cold start (sprays for about 8 seconds, then stops). However, the cold
>start injector does not operate at all on a hot start. The car does a
>"hot start" when I manually put 12 volts to the cold start injector for
>a few seconds while a helper starts the car.
>
>The other posts suggest that the failure is in the "hot start relay".
>I can not find a hot start relay on the car, or referenced as a part
>for this car. The only thing close is the CIS/Lambda relay. Is that
>it?
>
>I am about ready to add 12 volts directly to the cold start injector
>via a switch or, timer relay.
>
>Any suggestions?
>
>Thank you in advance!
>
>Jeff
 >> Stay informed about: 84 VW Rabbit GTI - Hard to start when hot 

The post alluding to vapor lock is probably correct. The CIS system is
very sensitive to having sufficient residual pressure in the system
when the vehicle is hot. Often the cuprit is the check valve at the
fuel pump. If the smallest speck of rust gets caught in the check
valve it will not close, and the fuel will return to the tank, ergo a
loss of pressure. Often this can be heard, when the engine is turned
off, it sounds like a series of pings coming from the area of the gas
tank outet. It sometimes is immediate and other times very slow
depending on the size of the speck of rust or debris.
One can check this by loosening one of the bolts that seure the
banjo fittings to the fuel filter --- if the check valve is faulty,
there will not be a sudden release of pressure. if the check valve is
ok you will get a spray of gas. One should be careful in doing this as
one can get a facefull of pressurised gas if the check valve is ok.
On my 81,82, and 83 rabbits there is a hot start pulse relay that
is not integrated into the fuse panel --- it is in its own separate
holder, usually affixed to the fuse box by tape or a tie fastener -- i
have also seen them merely stuffed behind the box or dangling loose.
Since i do not have a 84, i'm not sure where its located, but when
functioning property, it causes fuel to be injected on an intermittant
basis in very short squirts during the initial cranking. Its called a
hot start pulse relay and Bentley shows its location on page 49 of
section 4, above the fuse box and say it is identified by its three
terminals and part no 813 906 064. Every post 1980 rabbit has the
relay.
 >> Stay informed about: 84 VW Rabbit GTI - Hard to start when hot 

Bad cpr will cause a loss of residual pressure.

On 10 Sep 2006 20:02:27 -0700, rothring.TakeThisOut@peoplepc.com wrote:

>The post alluding to vapor lock is probably correct. The CIS system is
>very sensitive to having sufficient residual pressure in the system
>when the vehicle is hot. Often the cuprit is the check valve at the
>fuel pump. If the smallest speck of rust gets caught in the check
>valve it will not close, and the fuel will return to the tank, ergo a
>loss of pressure. Often this can be heard, when the engine is turned
>off, it sounds like a series of pings coming from the area of the gas
>tank outet. It sometimes is immediate and other times very slow
>depending on the size of the speck of rust or debris.
> One can check this by loosening one of the bolts that seure the
>banjo fittings to the fuel filter --- if the check valve is faulty,
>there will not be a sudden release of pressure. if the check valve is
>ok you will get a spray of gas. One should be careful in doing this as
>one can get a facefull of pressurised gas if the check valve is ok.
> On my 81,82, and 83 rabbits there is a hot start pulse relay that
>is not integrated into the fuse panel --- it is in its own separate
>holder, usually affixed to the fuse box by tape or a tie fastener -- i
>have also seen them merely stuffed behind the box or dangling loose.
>Since i do not have a 84, i'm not sure where its located, but when
>functioning property, it causes fuel to be injected on an intermittant
>basis in very short squirts during the initial cranking. Its called a
>hot start pulse relay and Bentley shows its location on page 49 of
>section 4, above the fuse box and say it is identified by its three
>terminals and part no 813 906 064. Every post 1980 rabbit has the
>relay.
 >> Stay informed about: 84 VW Rabbit GTI - Hard to start when hot