Guys, I have another problem, which is really making me insane, any
ideas would be appreciated.
When ever I get in the car and try to start it, It wont start at
first, it cranks for over 10 second to start, however, If I crank
it for 1 second, and let go off the ignition and try it for the
second time, it starts right up. Once it starts if I turn the
ignition off, wait for like 5 mins, then I try it starts quickly
again. If I wait over 6 to 10 minutes or over night, or couple of
hours, I have to crank it over 10 seconds or crank it twice to
start it. I already replaced the fuel filter thinking it would
solve the problem it didnt. Replaced the Spark plugs didnt make a
difference. Checked disributor and seems clean and no sign of wear.
While its running there is no rough idling. acceleration is pretty
smooth. I didnt check the fuel pressure, but I listened the gas
tank and when I turn the key on, fuel pump turns on for about 2 3
seconds as usual and stops, then as soon as I start cranking pump
starts as well, I assume pump is operating right . But what else
could it be?
Is there a cold start valve on these cars? or do you think Camshaft
position sensor might cause this?–
siktir
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You have a fuel pressure loss. Most likely because of
a bad check valve. One in the pump, one in each fuel
regulator and the fuel injectors work as fuel pressure
check valves.
When ever I get in the car and try to start it, It
wont start at
first, it cranks for over 10 second to start,
however, If I crank
it for 1 second, and let go off the ignition and try
it for the
second time, it starts right up.
I didnt check the fuel pressure.
You must to find the problem.
I assume pump is operating right .
But what else
could it be?
You are correct about the pump. It’s OK but the
system looses pressure. One try at starting only
begins to pressurise the system and the injectors will
not open until the pressure reaches the ammount needed
to force open the injector. This pressure is reached
durring the second cranking. Attach a fuel pressure
guage and you will see what I state.
I could be that the fuel rail is not holding pressure as it should
after shutdown. You need to put a fuel pressure gauge on the rail
to see. this could be caused by either a bad non-return valve (integrated
with the inlet pressure regulator on HE cars, or on the fuel
pump on preHEs), or leaky injectors, or a bad regulator.
When ever I get in the car and try to start it, It wont start at
first, it cranks for over 10 second to start, however, If I crank
it for 1 second, and let go off the ignition and try it for the
second time, it starts right up. Once it starts if I turn the
ignition off, wait for like 5 mins, then I try it starts quickly
again. If I wait over 6 to 10 minutes or over night, or couple of
hours, I have to crank it over 10 seconds or crank it twice to
start it. I already replaced the fuel filter thinking it would
solve the problem it didnt. Replaced the Spark plugs didnt make a
difference. Checked disributor and seems clean and no sign of wear.
While its running there is no rough idling. acceleration is pretty
smooth. I didnt check the fuel pressure, but I listened the gas
tank and when I turn the key on, fuel pump turns on for about 2 3
seconds as usual and stops, then as soon as I start cranking pump
starts as well, I assume pump is operating right . But what else
could it be?
Is there a cold start valve on these cars? or do you think Camshaft
position sensor might cause this?
I’d love hear any ideas. My XJ6 does the exact same thing…although never
to the point of cranking as long as 10 seconds…that’s quite a long time,
really.
Five or six spins, no start. Release key. Try again…motor running before
the starter gives even one full spin.
Or, go to eight or nine spins and it’ll start anyway.
It is very consistent. After many fruitless experiments to “cure” the
problem I gave up. Thinking, at one point, it was fuel drain-back I even
went so far (get a load of this, guys) to divine a fuel rail primer which
operated the fuel pump for 10 seconds whenever the driver’s door was opened
so that there was always pressure at the rail …before I even had the key
in the ignition. No help, but it was fun rigging it up.
Doug Dwyer
Longview, Washington USA
1987 Ser III XJ6
1988 XJS V12
Guys, I have another problem, which is really making me insane, any
ideas would be appreciated.
When ever I get in the car and try to start it, It wont start at
first, it cranks for over 10 second to start, however, If I crank
it for 1 second, and let go off the ignition and try it for the
second time, it starts right up.
// please trim quoted text to context onlyFrom: “sta” s_t_a@msn.com
Not sure if that’s quite the same symptom, Keith. …though they may well
be related.
What I am referring to, and what I think the other fellow is referring to,
will happen on any start-up, any time of day, hot or cold.
A) Either hold the key and the let 'er spin 'round a few times till she
fires OR B) let it spin just briefly, release the key, then turn it back
to “start”…and the engines fires instantly. And I mean instantly
Weird, huh ?
Doug Dwyer
Longview, Washington USA
1987 Ser III XJ6
1988 XJS V12
I’m experiencing the same condition. Any start after the first happens
immediatly anytime the same day.
I’m also on an odesey to get to the bottom of this problem. If I sit in the
driveway and start it immediatly after the initial start it starts right up.
Which seems a little like fuel as Doug suggests. But I’m not convinced.
Keith Morris
Seattle
'87 XJS
“Doug Dwyer” <@Doug_Dwyer3>
I’d love hear any ideas. My XJ6 does the exact same thing…although never
to the point of cranking as long as 10 seconds…that’s quite a long time,
really.
Five or six spins, no start. Release key. Try again…motor running before
the starter gives even one full spin.
Or, go to eight or nine spins and it’ll start anyway.
In reply to a message from Doug Dwyer sent Sat 23 Jul 2005:
I had a 93 Cadillac allante last year, it had the same symtoms, it
took 3 dealership to find out, 2 injectors were leaking inside the
pistons causing engine to choke and long cranking times, Does
anyone knows jaguars have the same particular problem? leaking
injectors or its not very common? I will check the fuel pressure
first, which one should I suspect first? pressure regulator on fuel
rail or check valve on the fuel pump? If it turns out to be the
fuel pump check valve, do I need to replace the whole assembly or
replacing the electric motor would do just fine? thinking cost is
over $700.
Thanks for all your help guys.–
The original message included these comments:
Not sure if that’s quite the same symptom, Keith. …though they may well
be related.
What I am referring to, and what I think the other fellow is referring to,
will happen on any start-up, any time of day, hot or cold.
I’d love hear any ideas. My XJ6 does the exact same thing…although never
to the point of cranking as long as 10 seconds…that’s quite a long time,
really.
Five or six spins, no start. Release key. Try again…motor running before
the starter gives even one full spin.
Or, go to eight or nine spins and it’ll start anyway.
// please trim quoted text to context only
In reply to a message from sta sent Sat 23 Jul 2005:
I was wondering, if I turn the ignition on pump turns on, and I
turned the ignition off, then turn it back on to pressurize the
system more, do you all think this will pressurize the system
enough to start at first ignition? or will the injectors stay
closed at first ignition and open up the at the second ignition?–
siktir
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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If you install a fuel pressure guage it’s easy to see
what is happening.
The fuel pressure bleeds off over time. An additional
second problem is heat boils the fuel. This boiling
increases at a lower fuel pressure.
So… The same starting problem occurs at different
temps, sit times, and starting fuel pump run times.
It can be very confusing to figure out unless you can
watch a fuel pressure guage over the course of a few
days.
Allowing the pump to run for the few seconds of
pressurization time at first key turn to ignition then
off and turn again to ignition will pressurize the
rail and decrease spin time before starting.
However if the fuel has boiled you will have to crank
to purge the system of vapor before the liquid fuel
will pass through the injectors and the engine will
start.
You cannot check FI psi by cracking open a fuel
fitting and watching the “gasoline” spray out. It’s
dangerous because of ease of ignition to fire and you
get the same “spray” of fuel when you have 5 psi or 50
psi. The minimum injector opening pressure is about
35 psi. Any less than this will not cause the
injector to be forced open even though the electrical
pluse has “opened” occured.
I understand there is an inline check valve that would
work if the fuel pump check valve is bad. Anyone done
this?
Not sure if that’s quite the same symptom, Keith.
…though they may well
be related.
It is very consistent. After many fruitless experiments to “cure” the
problem I gave up. Thinking, at one point, it was fuel drain-back I even
went so far (get a load of this, guys) to divine a fuel rail primer which
operated the fuel pump for 10 seconds whenever the driver’s door
was opened
so that there was always pressure at the rail …before I even had the key
in the ignition. No help, but it was fun rigging it up.
Definitely signs of geek with too much time on his hands
Not sure if that’s quite the same symptom, Keith. …though they may well
be related.
What I am referring to, and what I think the other fellow is referring to,
will happen on any start-up, any time of day, hot or cold.
A) Either hold the key and the let 'er spin 'round a few times till she
fires OR B) let it spin just briefly, release the key, then turn it back
to “start”…and the engines fires instantly. And I mean instantly
I had a 93 Cadillac allante last year, it had the same symtoms, it
took 3 dealership to find out, 2 injectors were leaking inside the
pistons causing engine to choke and long cranking times, Does
anyone knows jaguars have the same particular problem? leaking
injectors or its not very common?
I don’t know the frequency, but I imagine any injector can leak if
it gets dirty. At any rate, rail pressure will drop if that’s happening.
It will be hard to tell from leaky regulator/check valve though.
I will check the fuel pressure
first, which one should I suspect first? pressure regulator on fuel
rail or check valve on the fuel pump? If it turns out to be the
fuel pump check valve, do I need to replace the whole assembly or
replacing the electric motor would do just fine? thinking cost is
over $700.
I don’t know myself, but someone needs to clarify where the
check valve function is implemented on the HE. A while back someone
here said it was in the inlet regulator.
Given we often hear of HE regulators failing, usually with fuel
leakage into the intake manifold through the vacuum connection,
I would be inclined to replace the regulators first if the
rail pressure is not holding. After that, I’d have the injectors
refurbished.
In reply to a message from Ed Sowell sent Sat 23 Jul 2005:
I am going to buy a fuel pressure test kit to see if the pressure
goes down after I park it overnight or couple of hours. Now I saw
there are couple of advises, 1- check valve which is on fuel pump
is not holding the pressure, I found this part on the internet for
$46 something http://www.carpartsteam.com/JA_XJ6_Fuel+Delivery_Fuel+Pump+Check+Val
ve_019.html
2 pressure regulator on Fuel rail
which one is more likely to go out? I am asking you guys all these
questions since you all know how hard its going to be, to pull the
tank out the trunk and disconnect convertible top motor and
hydraulics and work on the fuel pump. Yesterday I changed the spark
plug gaps to .40mm since then It got worse now I have to crank it
at least 3 times to get it going. I assume this problem is
happening because of the miles of the car its a 94 with 49K miles
on it, last four years car was only driven 7000 miles, probably
check valve or pressure regulator cant hold the pressure anymore.–
The original message included these comments:
I don’t know myself, but someone needs to clarify where the
check valve function is implemented on the HE. A while back someone
here said it was in the inlet regulator.
Given we often hear of HE regulators failing, usually with fuel
leakage into the intake manifold through the vacuum connection,
I would be inclined to replace the regulators first if the
rail pressure is not holding. After that, I’d have the injectors
refurbished.
Ed Sowell
76 XJ-S http://www.efsowell.us/ed/myJag.html
On my car, at least, it is not a fuel pressure issue. I checked, checked,
and triple checked pressure readings and, as I mentioned, even rigged up a
fancy fuel rail priming system.
I think it is a glitch of some sort in the ECU where there’s a delay in
triggering the injectors…but that’s just guessing. I gave up long ago
tried to find the root cause. It’s more of a curiosity than a problem,
really.
Thanks
Doug Dwyer
Longview, Washington USA
1987 Ser III XJ6
1988 XJS V12
The fuel pressure bleeds off over time. An additional
second problem is heat boils the fuel. This boiling
increases at a lower fuel pressure.
// please trim quoted text to context onlyFrom: “Geoffrey Green” geoffgreen@yahoo.com
Yes that is different. My symptom is occurring just at the very first
initial start - any initial start, doesn’t have to be morning or night -
just the first start in any given day. Any other start and the car starts
at it’s first opportunity.
The only similarity is that I can (trying to test different theories) crank
the engine over once and quickly let go of the key. Then even though it then
become the ‘second’ start she starts right up. I can hear the pump prime
(just like every other start).
I used to think that it had something to do with a warm engine and when cold
it took a second or two to fire. It doesn’t spin and spin when cold it just
doesn’t fire immediately like all other times.
Keith Morris
Seattle
Not sure if that’s quite the same symptom, Keith. …though they may well
be related.
What I am referring to, and what I think the other fellow is referring to,
will happen on any start-up, any time of day, hot or cold.
A) Either hold the key and the let 'er spin 'round a few times till she
fires OR B) let it spin just briefly, release the key, then turn it back
to “start”…and the engines fires instantly. And I mean instantly
Weird, huh ?
Doug Dwyer
Longview, Washington USA
1987 Ser III XJ6
1988 XJS V12
In reply to a message from Keith Morris sent Sun 24 Jul 2005:
This is one of these posts that I’m glad to see…
I’ve been sitting with this issue now for a couple of months. When
I first brought my car home from the dealer it started perfect
within seconds everytime. Then, after about two months, it started
doing this 4-5 second cranking thing…and usually only after
overnight. I shrugged it off hoping it wouldn’t get worse…it
hasn’t but seeing these posts sure took me out of feeling alone
with the problems. I’ll lurk on and see who finds out what. Thanks.
In reply to a message from ixtlan22 sent Mon 25 Jul 2005:
I added a check valve on the fuel rail and problem is gone, turn
the ignition on, at first crank before a full spin finishes car
starts. better than buying a fuel pump assembly.–
siktir
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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In reply to a message from sta sent Thu 28 Jul 2005:
You should post a part #, cost, where to buy and how to install.
I’ve read LOTS of posts on this and on the old ‘‘moderns’’ list of
the fuel pump check valve problem, and you are the first person who
has solved it. And you didn’t even have to remove the tank!!
My in tank check has always been reliable (starts first crank), but
if it ever starts to leak, I’ll be looking to you for advice.
Good to see some innovation,
Richard–
The original message included these comments:
I added a check valve on the fuel rail and problem is gone, turn
the ignition on, at first crank before a full spin finishes car
starts. better than buying a fuel pump assembly.
