[x300] Won't start, narrowed down to the injectors (I think)

X300
1

First, sorry to ask this because I’m certain the info is on
here somewhere. But, I have now looked at so many threads
that they’re starting to blur together and I still can’t
seem to find the information I think I need.

Here’s the problem: '96 4.0 VDP. No problems at all, then
it just wouldn’t start one morning. I turns over freely,
but it just refuses to even attempt to fire.

I have checked and swapped the fuel pump relay. I have
confirmed that the fuel pump is at least providing some
pressure as I can hear it engage, and when I barely cracked
open the line between the pressure regulator and the fuel
rail, it spewed a nice, fine stream of gasoline.

The car will fire and run for a second or two with a shot or
two of starting fluid, so I know I’m getting spark and
timing. That seems to rule out crank or camshaft position
sensors.

Therefore, since there is fuel in the fuel rail that is
apparently not getting into the cylinders, I believe I have
some issue that is keeping the injectors from firing. I
have seem numerous suggestions in similar cases to check
that they are getting a signal, but I don’t know how to do
that. Some have suggested a test light is insufficient
because of the small amount of voltage and the brief period.
And anyway, I am at this point fairly certain that the
injectors are not getting the proper signal based on the
other tests.

So, IF the injectors are not firing, THEN what should I look
at next? Is there yet another relay or fuse hiding
somewhere besides the obvious that might cause such a
problem? I have one book that shows an injector relay
behind the right headlight, but it says that is only on the
V12. For the 4.0, it says it’s an ‘‘ECM Controlled Relay.’’
Nonetheless, I have swapped it with another close by to no
effect. (I have FINALLY ordered my repair CD’s, but they
may be in the mail for a few days.)

Thanks to EVERYONE for ANY suggestions at this point. I’m
going to go scratch my head now and keep thinking.–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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2

In reply to a message from jeremywatson sent Thu 23 Jun 2011:

Jeremy,

For what its worth, here goes what happened to mine.

Drove in the driveway, got dressed and primed to take spousy out
for dinner, X300 turned over, NO fire. MMMM, bloody Jaguar, all
dressed up, so took ‘‘her’’ XJ-S V12 and heard all about my ‘‘new’’
Jaguar being unreliable for way too long over dinner, Bugga.

Next day, sober, well sort of.

Tested all and sundry, almost identical to your list.

The relay {Blue} in the RH under hood (bonnet) fuse box was
suspect, as it is the primary ‘‘ignition relay’’. Dissmantled and
cleaned the contacts, they were grubby.

Still no start.

Probed the wires TO the crank angle sensor and established that it
had voltage with ignition ON, and since that voltage is supplied by
THAT relay, sweet.

Still NO start.

Got fuel, same test as you.

Stole a crank angle sensor from the neighbours car, started
straight up, double Bugga. Put my sensor on his car, NO start.
Fault established. New sensor sourced and all sweet.

I still have the old sensor and see no reason for its failure, as
there are NO moving parts. I am now hearing that they die at about
100k miles, and mine was 163k kms (just over 100k miles), so who
knows???.–
The original message included these comments:

First, sorry to ask this because I’m certain the info is on
here somewhere. But, I have now looked at so many threads
that they’re starting to blur together and I still can’t
seem to find the information I think I need.
Here’s the problem: '96 4.0 VDP. No problems at all, then
it just wouldn’t start one morning. I turns over freely,

–
Grant Francis 85 XJSV12 (Hers), '96 X300 XJ6 3.2l (My Cat)
Adelaide South Austarlia, Australia
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1 Like
3

In reply to a message from jeremywatson sent Thu 23 Jun 2011:

When you turn the key on and all dash lights come on, abs, battery
etc. Does the check engine stay on or go off? If it goes off prior
to start it MAY be a problem in the ECU. I recently bought a 96XJR
that had that symptom. It was a broken pin in ecu.–
The original message included these comments:

Here’s the problem: '96 4.0 VDP. No problems at all, then
it just wouldn’t start one morning. I turns over freely,
but it just refuses to even attempt to fire.

–
Nick 67 E-Type 67 S-Type 65 S-Type 96VDP 95XJR 96XJR
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1 Like
4

In reply to a message from Nick Hand sent Fri 24 Jun 2011:

Jeremy

Favourite for a non-start does seem to be the crank sensor.
It should have a resistance of 1.25Kohm and inductance of 1
henry - but even if it has, may not work properly.

Let’s face it, how would you enjoy being stuck on the front
of a vibrating engine, subject to many cycles of cold from
the front and hot from the back and still be expected to
give an accurate pulse every revolution for 15 years ?

I know you’ve checked some of this already but see my page
http://tinyurl.com/66ckn2v and also
http://tinyurl.com/6awrvtp which may give you many more
ideas and/or concerns.

Best wishes from Jim Butterworth
http://www.watchet.dolphins.btinternet.co.uk/

I never Fail, I just succeed in finding out what doesn’t work–
The original message included these comments:

it just wouldn’t start one morning. I turns over freely,
but it just refuses to even attempt to fire.

–
1995 3.2 Sport - http://www.jag-lovers.org/v.htm?1262090878
Somerset, United Kingdom
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1 Like
5

In reply to a message from sfj642 sent Fri 24 Jun 2011:

Thanks to you all for your help.

In response, yep, the check engine light stays on. One of
my first thoughts too was the immobilizer (although I have
yet to hear a definitive answer on whether the U.S. cars
were fitted with them).

I would think that starting with starting fluid sprayed in
the breather would rule out just about all causes other than
a fuel issue, but then again I have been wrong once or twice
before. I should perhaps have mentioned that I do not smell
any fuel in the exhaust even after very lengthy cranking.

As I have the '95 parked right next to her (with all those
useful parts) I’ll try swapping the crank sensors this
weekend and see what happens.

Will report back. Thanks again.

P.S. Got my JDHT disk in. Haven’t had a chance to pick
through it much yet, but hoping to find a section that says
‘‘Hey, dummy: if your car won’t start, try the following in
this order.’’ Keeping my fingers crossed.–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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6

In reply to a message from jeremywatson sent Fri 24 Jun 2011:

Walking the dog a thought sprang to mind on these models, if
the ECU thinks that you have set a WOT whilst turning over
if cuts off the injectors to clear any flooding. I’d look in
the area of the TPS inputs to the ECU. It’s something like
Fig. 04.2 in the Electrical Guide of the JTIS.–
The original message included these comments:

a fuel issue, but then again I have been wrong once or twice
before. I should perhaps have mentioned that I do not smell
any fuel in the exhaust even after very lengthy cranking.

–
Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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1 Like
7

In reply to a message from sfj642 sent Fri 24 Jun 2011:

So, here’s the update so far:

I have swapped the crank sensor from the car that was
running fine to the one that won’t start with no change.
The good one still starts and the dead one is still just
cranking. Checked both sensors before I swapped them and
the known good showed 1445 ohms while the suspect one showed
1356. Close enough I guess since the good car started fine
with either. Both seemed to flutter and change quite a bit
when I waved them across (or stuck them to) something metal.
So cross off the crank sensor.

I also went back and re-checked all the fuses and relays
mentioned on Jim’s site (great resource by the way). Pretty
sure I had checked them all before, but it was worth another
look. I also checked the white multi-pin connector behind
the right headlight, but it was clean as a whistle. I
cleaned all the contacts anyway, but still no change.

I am running out of ideas, so my next planned tests are these:

First, I’m going to throw a test light on the ‘‘controlled by
ECM’’ relay on the good car to see how it should be acting.
Then I’ll check the non-starter and compare.

Second, I’m going to pull the ECM from under the dash and
check for corrosion, etc. Not quite sure how to check it
for anything else, but I saw some suggestions on Jim’s site
so I’ll go back and check that again (again, great resource).

Third, I’m going to pick up a fuel gauge and actually check
the fuel pressure rather than just cracking open the
connection at the rail to confirm the presence of fuel as I
have done thus far. I was thinking about trying to put a T
in right after the pressure regulator where the metal line
screws on. Anyone know exactly what size/type that fitting
is? I also considered just replacing the fuel pressure
regulator with one of those pretty, anodized adjustable ones
with the gauge built in. If anyone has any thoughts on the
advisability of either option, please speak up.

So thanks for the suggestions so far, but I’m still trying
to locate the problem. Will update later if for no other
reason than logging it all here will make it easier for me
to track down next time I have a no-start.–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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8

In reply to a message from Neil Maldon sent Sat 25 Jun 2011:

Thanks for the suggestion. If I just disconnect the TPS, do
you think the computer will realize it’s getting no signal
and compensate? That would undoubtedly throw a check engine
light, but if it stated it would help locate the problem.
Or do you think disconnecting the TPS will just keep it from
starting anyway?–
The original message included these comments:

the ECU thinks that you have set a WOT whilst turning over
if cuts off the injectors to clear any flooding. I’d look in
the area of the TPS inputs to the ECU. It’s something like
Fig. 04.2 in the Electrical Guide of the JTIS.

–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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9

In reply to a message from jeremywatson sent Sat 25 Jun 2011:

Jeremy,

I believe the fuel line connections to the fuel rail will
be M14 x 1.5mm, the same as on the AJ6 engines - but if you
want to check the pressure you need to fit the gauge in the
feed line before the fuel rail, not downstream of the fuel
pressure regulator.–
The original message included these comments:

Third, I’m going to pick up a fuel gauge and actually check
the fuel pressure rather than just cracking open the
connection at the rail to confirm the presence of fuel as I
have done thus far. I was thinking about trying to put a T
in right after the pressure regulator where the metal line
screws on. Anyone know exactly what size/type that fitting

–
Bryan N, '91 Sovereign 4.0 L, RHD
Cambridgeshire, United Kingdom
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10

In reply to a message from jeremywatson sent Sat 25 Jun 2011:

Hopefully pulling out the ECU will find it, it could be a
broken or shorted pin on the connectors. Not sure if it is
feasible, but is it possible to take out an injector and
actually check that it is squirting fuel, as the car is
being cranked?

As Jack might say: ‘‘just a thought’’, spark, fuel and motion
plus suck/blow (compression) are the only components needed
to make it run! Throwing parts at it won’t cure it neither
will money, although it’s generally one and the same thing!–
The original message included these comments:

So thanks for the suggestions so far, but I’m still trying
to locate the problem. Will update later if for no other
reason than logging it all here will make it easier for me
to track down next time I have a no-start.

–
Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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11

In reply to a message from jeremywatson sent Sat 25 Jun 2011:

Jeremy, the TPS is a pot and sends a voltage to the ECU,
what that expects to see whilst cranking with no throttle I
have no idea, though I suspect it maybe 12+ volts,
disconnecting may or may not give a floating input which may
work but I think not. You need to use the JTIS and it’s
Electrical Guide to compare the inputs on that line when
starting up on both the good car and the problem one, use a
voltmeter and a pin to pierce the insulation to see what you
are getting.–
The original message included these comments:

Thanks for the suggestion. If I just disconnect the TPS, do
you think the computer will realize it’s getting no signal
and compensate? That would undoubtedly throw a check engine

–
Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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12

In reply to a message from Neil Maldon sent Sat 25 Jun 2011:

I THINK the ''pull the TPS lead reference is to rule out the
possibility that the TPS is falsly indicating WOT. On the X308,
anyway, the WOT signal inhibits the fuel injection as a means to
clear a flooded engine. I dunno if the X300 has a similiar control
strategiy–
Ross - 89 XJS, 98 XJR, 99 XJR, 02 XJ8
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13

In reply to a message from sparkenzap sent Sun 26 Jun 2011:

Ross, it does, hence the thread.–
The original message included these comments:

clear a flooded engine. I dunno if the X300 has a similiar control
strategiy

–
Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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14

In reply to a message from Neil Maldon sent Sun 26 Jun 2011:

Update # whatever I’m up to:

Disconnected the TPS on the known good car. It still
started just fine. However, if you press on the
accelerator, the car tries to flood and die. But it WILL
start with the TPS disconnected.

The bad car will NOT start with the TPS disconnected.

I swapped the ECM from the good car with the one from the
bad car (more detail in another thread). The bad car still
did not start with the known good ECM installed. However,
while the good car did start with the suspect ECM, it ran
horribly: rough idle, hesitation and surging while driving,
check engine light for P0300 ‘‘multiple misfires,’’ etc.

Don’t know what that means. Maybe the ECM’s aren’t
interchangeable.

I have NOT removed an injector or pulled the line off the
fuel rail to check the fuel pressure again yet. I had to
order a fuel pressure gauge since there weren’t any
immediately available. Figure I’ll plum it in before the
fuel rail when it comes in and check the pressure at that time.

Will update more later, but running low on patience.–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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15

check your coil packs, just under the cover that says “Jaguar” on the engine. just a thought since the rough idle happened to me and the error code was the same.— On Mon, 6/27/11, jeremywatson jeremy_watson@yahoo.com wrote:

From: jeremywatson jeremy_watson@yahoo.com
Subject: Re: [x300] Won’t start, narrowed down to the injectors (I think)
To: x300@jag-lovers.org
Date: Monday, June 27, 2011, 2:38 PM
In reply to a message from Neil
Maldon sent Sun 26 Jun 2011:

Update # whatever I’m up to:

Disconnected the TPS on the known good car. It still
started just fine. However, if you press on the
accelerator, the car tries to flood and die. But it
WILL
start with the TPS disconnected.

The bad car will NOT start with the TPS disconnected.

I swapped the ECM from the good car with the one from the
bad car (more detail in another thread). The bad car
still
did not start with the known good ECM installed.
However,
while the good car did start with the suspect ECM, it ran
horribly: rough idle, hesitation and surging while
driving,
check engine light for P0300 ‘‘multiple misfires,’’ etc.

Don’t know what that means. Maybe the ECM’s aren’t
interchangeable.

I have NOT removed an injector or pulled the line off the
fuel rail to check the fuel pressure again yet. I had
to
order a fuel pressure gauge since there weren’t any
immediately available. Figure I’ll plum it in before
the
fuel rail when it comes in and check the pressure at that
time.

Will update more later, but running low on patience.

'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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[forums.jag-lovers.org]–
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16

In reply to a message from fd sent Mon 27 Jun 2011:

Sorry if I wasn’t clear. I have two cars, one won’t start.
When I took the ECM out of the car that wouldn’t start and
put it in the car that was running well, the car that had
been running well started the lumpy idle, etc. When I
swapped the ECM’s back, everything smoothed out. So,
definitely not a coil problem.–
The original message included these comments:

check your coil packs, just under the cover that says ‘‘Jaguar’’ on the engine. just a thought since the rough idle happened to me and the error code was the same.

–
'96 VDP 4.0, '95 XJ6 4.0, and '96 XJS 4.0
Dallas, Texas, United States
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