So thanks to help from JagTechOhio and Brutal I was able to find a couple of O ring problems and changed the #6 injector and I have not gotten the P0306 or check engine light in weeks.

I suppose I thought it was related, but when I was having the injector problems I was also having hard start problems. Well I think I've got the injector piece fixed but I'm still having trouble with the hard start.

The symptoms:

1) first the ing in the morning the car starts perfectly 98% of the time
2) if I drive somewhere and shut off the car for less than 15 or 20 minutes it starts normally 99% of the time
3) If I shut off the car for more than a half an hour I have to hold the gas pedal down or pump the pedal to get the car to start. Otherwise it cranks and cranks and won't seem to start.
4) if the car sits for several hours it "almost starts", like it will sputter and choke and if I gas it quick enough it will tke off, but sometimes it just dies.
5) if it sits over night and I come out in the morning, we're back to 1, it starts just right almost every time.

Other things that may or may not be helpful:

1) while swapping injectors I would sometimes not get any fuel to come ut the schrader valve (or whatever you call the tire fill valve like thing on the fuel delivery rail). Fuel always drained out of the line when I disconnected it, but sometimes it didn't seem to be under as much pressure.

2) I've tried just turning the key on before trying to start thinking maybe the fuel pump needed to kick on and pressurize the line, the results have been mixed so I can't say if it helped or not.

3) The problem isn't 100% anything. Sometimes it hard starts after a short drive. Occasionally it starts perfect all day. I'd say 98 to 99% of the time it's like I described above though.

So now my question is what should I look at / test / inspect? As always any help is appreciated. Thanks.

 

That sounds like you're going to have to test with a fuel pressure gauge to identify whether the pump is not coming on every start-up, or whether it is not maintaining pressure in the fuel rail when shut down.

 

I didn't go so far as to do as Brutal suggested to someone and tape the pressure guage to my windshield, but I took one with me as I drove around different places this week. I'm sure I'm not the only guy that's ever been caught working on his jaguar in a parking lot in the middle of the night or on any random afternoon.

Anyway, what I found is that when I turn the key on, I get around 44 psi and when the car runs, even rough idle or hard start, I get 36 to 38 psi.

So, now what?

 

we just had a big meeting with the regional Jaguar tech rep on this very problem. And its been determined that this is an injector problem from dirty injectors. And no an on board cleaning or tank additive will not fix(maybe temp). they even showed video of what happens. The injector is basically leaking. the fix Ultra Sonic cleaning. So much so that Jaguar is considering pushing a $8k dollar machine to do it and flow check. But that will probobly not happen due to cost. But you can send your injectors to Chris
who has this machine and has been doing this for awhile..he'res a link
http://injectorrx.com/

 

So that's interesting, because that's the issue mechanic 1 was trying to solve, he said he ultrasonic cleaned the injectors and flow tested them. The problem just never celared up. Is it possible it just needs multiple cleanings? Mechanic 3 did an on board clean which did help temporarily.

What about contaminants in the fuel tank, I don't know the previous owner of the car and I don't know what gas they put in it.

So assuming I can get a good ultrasonic clean is there anything I can do to keep the problem from comming back? I use 91 or better octane fuel and I try to get it at the same place all the time.

Are there fuel or fuel additives recommendations? What about gas stations? Around here people try and avoid a certain station because all their gas has ethanol blended, is this a rational fear? What about the cheveron stations with the "special blends"? In fact most gas chains claim to have one additive or another.

Thanks for the help.

 

Well and that brings up another point, were they checked for rust? Cause now we're also finding that with the amounts of ethanol(alcohol absorbs water) the inside of the injector which is not stainless is rusting. And then there are issues with crub in gas, tank, and stations that lead to the problems all over again. When the mechanic said he had them sonic cleaned, did they have the machine? Send them out or lied

 

does this one sound like a leaky injector issues also? :
1) 98 xjr - 1st start of day (after 5-8hr sit) it will not start. When I try to start again with pumping gas pedal, usually starts (sometimes takes 3-4 tries) - priming may or may not help, it's hard to tell
2) the rest of the day, it fires up right away. Problem only occurs after 5-8hr sit.

I would think leaky injector issues would be more likely to be problematic after the car has been running (as with xj8johnny), but who knows. I've posted about this issue several times - replaced many parts, still not resolved.

 

I'm not actually sure they cleaned all the injectors, maybe just the one bank. The mechanic that did it had to send them out and may not have sent them all. I found a guy that has an ultrasonic clean / flow test machine locally. He wants $12 an injector if I bring them in. Since one is brand new, I'm going to take them in and see what he says and how they compare.

While I'm at it, can you tell me where the fuel filter is located. I haven't actually looked for it yet, but I'd prefer to start looking in the correct location (2000 XJ8 VDP) I'm sure I've got enough pressure, maybe not enough flow? I can't say for sure when or if the filter got changed. Thanks.

 

the filter is over the left rear axle. it takes a common GM can fuel filter avail at any autoparts store. Theyre NOT special

 

It's funny that you say it's not special, because I stopped by the Ford dealership for something yesterday and asked (out of curiosity) what they wanted to change the fuel filter on "the jag", he told me around $75 to $100 and I said "wow, is there that much labor involved?" to which he replied, no, it's just an expensive filter.

I bought a Fram for $14 and just like you said, it's a common canister type. I'll probably change it tomorrow night when I pull the injectors to take them in for the cleaning. It looks like it hasn't been changed in a while, but I suppose being up under the car it gets dirty and rusty faster than if it were elsewhere. You probably can't tell by looking at the outside. I'll be interested to see what the filter has in it.

 

I had a freind 1 time(i still have friends.. ) and he did a rough in estimate to build a $25k car in parts purchased seperatly......was over $300k

 

I changed the fuel filter, it didn't seem too bad once I actually got it out.

I had the injectors cleaned. $12 per injector plus the cost of new "o" rings on the top and bottom. They said that they ran a long time on the clean cycle. I guess it has some pressure / flow diagnostic as it runs that lets you know when they are done.

I got everything back together with minimal hassel and I took the car on it's maden voyage. I only drove about a mile and started and stopped the car a few times. I'll give it a real road test this weekend. Keep your fingers crossed... I know I will.

Sometimes I wonder how many other guys drive around with the code reader connected... Just in case....

 

did they flow check them or just clean? cause if they didnt flow check they have no way of knowing if they leak, flow too much or crappy pattern....
go here a see and read
http://injectorrx.com/
This is the friend of mine I work with on injection systems and hi po work

 

Yeah they did a flow check before and after the procedure. They also said the repeat the process if any fail. In the end the mechanic said the spray pattern looks good and have good even flow.

 

Just a side note, but I wouldn't leave a generic reader connected when driving. I had an Actron hooked up to a 2000 XJ8, and it would repeatedly throw the car into limp mode after about 5 miles of driving while it was still connected. There wasn't a single thing wrong with the car, it just kept trying to spit out the scanner.

 

So... The good news is the car is running FANTASTIC. It's responsive and accelerates better than it ever has. I really can't beleive the difference.

The bad news is that it hard starts every time now. It's a strong hard crank, and now it will eventually start without me depressing the gas pedal, but it never turns right over. If I depress the gas pedal slightly when I turn the key it will fire right off most of the time though.

As for ther code reader, it's plugged into the OBDII port but powered off, the car is running so well I'm afraid to disconnect it. Owning a Jag has made me superstitious

 

Hey Johnny, as long as it's not a black cat, go ahead and unplug it.

 

Since the injector clean, no missfire, no rough idle, no issues whatsoever on that front. That really did seem to fix the problem. The car purrs like a kitten and performs fantastically.

Sadly though my troubles aren't over, I've left the code reader plugged into the OBDII port because the P0121 "Throttle position sensor" error is back with a vengance. I get the error two to twelve times a day while driving, I reset it and the car runs flawlessly.

Per JagtechOhio, I thought maybe the code reader was inducing the problem, so I left it home one day. Instead of being able to reset it on the fly, I had to stop the car, shut it off and restart it to clear the "Engine Failsafe, ASC / trac not available"

So I guess at this point I'm a throttle body replacement canidate, unless anyone else has any ideas. Thanks for all the help and moral support.

 

Oh and as a side note, I've just decided to live wit hte hard start, because the car runs great but the hard start still hasn't gone away.

 

Well Johnny, I guess you have learned something about the particular guy at the particular Ford dealer.