Mechanics

HELP NEEDED PLEASE

2003 Jaguar X-Type • 68,000 miles

I need some help

I have a Jaguar x-type 2.1LT petrol

for two weeks theres been a problem with my car,
when the car is cold for 14 hours and I start, it starts slow.

What I have checked and What I have done and replaced to the car in the last ten months is in the list below:

Brand New battery
The starter is good it has good voltage, alternator is good and voltage is good.
fuel pressure is fine 4.5bar as it should be
vaccum is not leaking and neither is oil leaking from anywhere
spark plugs were changed 6 months ago in perfect gap. Coils are fine, cables are fine.

ps for a few days I have noticed that if before starting the cold car I press on the gas pedal and release it and start up, it starts normal

then I thought it might be the throttle position sensor, I then changed the whole throttle body that I bought on ebay. But the problem is still there

I think there might be a problem in Crankshaft

what do you think it could be? What advice can you give me please

The ECU is not giving me a code, when I attach the laptop to ecu everything is normal.

I have had jaguars for some years and have basic knowledge but some things one can get stuck

my 735-rpm in idle and ignition timing 3-degrees

i have spent too much money and am sick of it


Thankyou


Avatar
Zibby
July 16, 2012.



Did you monitor the fuel pressure when it is cold and starting slow? If it is not retaining the correct pressure, it will have an extended crank.

Roy


ASEMaster6371
Jul 16, 2012.
Hi thanks for quick reply

first of all I have a permanent fuel pressure gauge and if theres any leakages with in a hour the pressure goes down. It takes overnight for the pressure to go down.

When I put the ignition in on position but dont switch on engine the pressure is perfect. I do not think there is a issue pump.

What I dont understand is when I release gas pedal before start the it starts up fine. It means that after I open and close the throttle body and start the engine its fine but why?

The throttle body is new so what can be the problem,
thank


Tiny
Zibby
Jul 16, 2012.
Check the idle air control valve. The passage may be carboned up.

Roy


ASEMaster6371
Jul 16, 2012.
Air control valve is new as you can see in pic attached.


Tiny
Zibby
Jul 16, 2012.
Ok. Back to my request, what about the actual passage?

Roy


ASEMaster6371
Jul 16, 2012.
Sorry for late reply
this pictures maybe help you?


Tiny
Zibby
Jul 16, 2012.
Hi
i have attatched photos so you can look at the ecu info at idle. The throttle body and air control valve, I replaced them last week after cleaning them so they are carbon free. Please help, ive had jaguars for some years and do have basic knowledge but here im stuck thankyou


Tiny
Zibby
Jul 16, 2012.
Only problem is engine (slow cranking about 3 seconds then start) every first time start only


Tiny
Zibby
Jul 16, 2012.
The last thing I can think of without testing the car myself is the coolant sensor readings.

Roy


ASEMaster6371
Jul 16, 2012.
Hi thanks for reply, the reading for the coolant sensor is after about 20minutes drive and is normal. The reading is in F not in celsius

one thing I dont understand and its the reason I am chatting to you is: on a cold engine before I start, if I press the acceletator once and then start the engine, it starts up fine. Why is this happening? The throttle body butterfly is completely clean and never gets stuck. I have checked the vaccum, break boot and its all fine. The rpm above is that right?
Could you reply in detail please, thankyou


Tiny
Zibby
Jul 16, 2012.
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