Hi all,

So I'm having a problem which appears to have been a problem that others have had in the past. But, I've tried some of those tricks, and my car seems to be doing something a little different.

Here's the issue: if I drive my S-type, and say I go get lunch, by the time I'm leaving the restaurant, it has a long cranking time (usually it seems to take 5-10 seconds, between two attempts). This only seems to happen if I let it sit for 30 minutes or more. If I go home and park it overnight, and try to start it the next morning, same thing: hard to start. BUT if I let it sit for 2-3 days, it starts up the first time no problem, but as the day goes on, it's hard to start again. So it's strange to me that letting it sit for 2-3 days offers a perfect start on the first start of the day, but no other time.

The first thing I tried was the key-cycling suggestion (where you turn the key 3-5 times to let the pump prime itself). No change. Also, on suggestion of one other topic in the forum, on a separate occasion I primed the pump one time, and depressed the schraeder valve to see if air or fuel came out, and it definitely had fuel.

I checked the fuel pressure with both my OBDII and a manual gauge on the fuel rail, that seems fine and within spec (I don't recall the spec as I checked that over 2 weeks ago, but at the time it matched what the manual says).

What should I check from here, given my symptoms?

Thanks in advance!

 

I'd check the vital temperature sensors (ECT, IAT, and I suppose CHT). It will fuel to what they say so if any is wrong then so is the fuelling.

 

2001 Jaguar S Type 4.0 V8 99,700 miles

Hello, Pilotmanitalia , thanks for the thread I am having the exact same issue, with the. Starting it does the same thing, have you figured out what was causing this?? If so please respond as I am lost on this one.

Also JagV8 where are these sensors ( ECT, IAT and CHT located), please detail description so I can check these possible issue

 

Just read each with OBD.

Otherwise it's much much more effort but see JTIS.

 

Excessive cranking time is indicitive of the Fuel pump or transfer pump beginning to fail - also, when was the last time the fuel filter was changed? They should be changed yearly or 10K miles - this is a filter that is often overlooked...

To add, one turn of the key should be sufficient to prime the pump and fuel lines - if you have to cycle the key 3 - 5 times - this is NOT normal and is not going to get you very far. I suggest if you don't know when the fuel filter was changed just go ahead and do it - it's rather simple (under driver's side plastic inner wheel well liner)

When changing if you find dark brown or black fluid/materials coming out the filter - odds are your fuel, transfer or both pumps are shot or close to death and will require replacing.

If the fuel filter checks out - then focus on fuel injectors but my money is on a clogged fuel filter or fuel/transfer pump intermitient failure.

 

OK everyone. Sorry about how long it took to get this updated! Since my first post, I've been mostly driving my other car and only occasionally driving this one so I just lived with it. It was finally getting worse about a week ago, and since I want to drive the car more now that summer is here, I decided to go ahead and start checking some things. Finally today, I checked what I suspected was the issue, and what I found confirmed that.

I pulled the fuel rail off and found several leaking fuel injectors. I'm ordering the new ones (getting re-manufactured units off of ebay).

Basically, you pull the fuel rails (but leave the injectors in), and turn the key to the on position but DO NOT start the car. If any of them drip (mine were actually pouring out), that's your problem.

The checks I'd done up to this point were I checked the fuel pressure and confirmed that it was leaking. This made me suspect the fuel pump, regulator, or leaking injector(s). A while back, I removed the pressure regulator and bench tested it with a mightyvac. Prior to that, I'd checked it on the car by removing the vacuum lines and checking for fuel odor/fuel itself. All of that checked out.

I'm a PhD student, so I apologize that I got so busy that I haven't been able to really review this for all this time until now!

Once I get the new injectors in, I'll confirm whether this fixed the issue or not.

 

Good luck and we're always pleased to get a follow-up, even a late one. In case you don't know, injectors can be flow tested and I think the firms can also supply replacements - but ebay may well be good enough. There are likely O rings or the like, which ought to be renewed when you refit the injectors.

 

Thanks for the update, I've marked the title resolved, so hopefully you are right, sounds likely I think.