X-Type ( X400 ) 2001 - 2009
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Throttle position sensor

 
  #41  
Old 06-23-2018, 09:56 AM
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Patterson: Glad you discovered the damaged intake gasket. That would explain the misfires & rough idle.

The ECM tries for an optimal 14.7 pounds air / 1 pound gasoline, by measuring air intake and controlling the fuel injection accordingly. The damaged #6 intake gasket let extra air leak in, which the ECM didn't know about, so #6 was lean and misfired. Replacing the gasket should fix this, and since you're already cleaning the fuel injectors, that can't hurt.

When you reassemble the fuel rail & 2 lower halves of the intake manifold, stuff 6 small rags into the cylinder intake ports so nothing falls into the cylinder heads while you work. The fuel rail assembles like a jigsaw puzzle, with a some patience & persistence.
 
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  #42  
Old 06-24-2018, 07:38 PM
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Thanks again Mr. Clapp! On re-assembly of the fuel rail, certainly a jigsaw puzzle, a 3 space one to boot!

At first I thought I could place the lower intake manifolds, with the fuel injectors inserted, onto the motor then bring down the fuel rail and insert the injector tops into the rail ports, and, plug them all in after that. Not the case. You have to hold the fuel rail and plug the injectors in, then push the 2 manifolds onto the injectors, trying to get the thunk feel so they are seated correctly, Then, while holding this fuel apparatus with everything dangling around, push in all the plugs from the harness. Four out of my six connector clips broke upon dis--assembly, but they did hold okay after being plugged together.

Next, set the whole assembly down into place, making sure to land the bottom surface of the lower intake manifolds onto the motor w/out damaging the rubber gaskets (like I did the first time). Then torque everything down and make sure the fuel injectors seat on both ends, potential air leak here. You might think the compressing of the fuel rail on top of the injectors, and, the injectors sitting in the manifold would be enough pressure to seat them after tightening the manifold bolts and fuel rail mounting bolts, but even with everything tight I poked a flashlight into the intake hole and saw some light coming up around one of the fuel injectors where it seats into the manifold. It's kind of a Peter or Paul thing, if you push the injector down to seat good in the manifold, it unseats a little from the fuel rail.

That's where I am now, I'm about to attach the retaining clips that secure the injectors to the fuel rail, and put the rest back together. Finding that I need a new battery too, so will have to get one b4 starting the car this evening.
 
  #43  
Old 06-24-2018, 09:51 PM
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Speaking of needing a new battery, the one I had and just returned was only 10 months old. When I removed the battery for this repair I noticed that the clamp for the negative side had white crusty corrosion on it. The positive side was clean. Wondering how to check for an electrical grounding problem.
 
  #44  
Old 06-24-2018, 10:55 PM
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Autozone ended up giving me a new battery. I got everything back together and tried to start the car. It would not kick over. I got out of the car and smelled gas under the hood. At first I thought the fuel injectors were leaking, but then I found the leak pictured below. Is this the fuel pressure regulator? Looks like I need a new one.
 
  #45  
Old 06-24-2018, 11:37 PM
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Yup
 
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  #46  
Old 06-25-2018, 02:22 AM
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Bought it. Thanks!

What else can I do? This is getting a little bit hilarious.
 
  #47  
Old 06-25-2018, 05:13 PM
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Mod light your car like I have, lol
 
  #48  
Old 06-25-2018, 05:56 PM
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Well, there was about to be light under the hood in the form of flames. As bummed as I was to have put everything back together and find the fuel pressure sensor spraying fuel, I'm lucky it didn't happen when I was driving in the Phoenix heat. It's about 108 today. Spraying fuel vapor on a hot engine in the summer in traffic could have started an engine fire.

For sanity I'll look at this as if I'm counting my lucky stars
 

Last edited by Patterson; 06-26-2018 at 01:35 AM.
  #49  
Old 07-17-2018, 01:44 AM
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The chronicle continues. I pulled the intake and replaced the leaky gasoline jet spray sensor. The car started, and runs a little rough, with an almost periodic misfire. It's as tho the engine has a hiccup in there somewhere. It does what might be like a weird shake every once in a couple seconds. It's actually gotten a little better for driving it, maybe the injectors are seating.This could also be an illusion, but it has power when I hit it at higher RPMs. Not going into Limpmode at this time, but, I'm waiting for a new engine light.

I've cleared the codes for cylinder 6 misfire. It still stalls (sometimes) after warming up. I suspect the clocking of the TPS. It may be interpreting idle as a different value than does the ECM.

Fuel Trims! The graphic below is what I've screenshot so far using the Torque app. I'll have to set this display up tomorrow so I can see it while driving and take live screenshots. I pulled this screen together to show the best of what I could glean from the app. I'd like to better define the headings.

 

Last edited by Patterson; 07-17-2018 at 02:05 AM.
  #50  
Old 07-17-2018, 02:01 AM
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Fuel pressure on the low side.
 
  #51  
Old 07-17-2018, 02:10 AM
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Really good explanation of short and long term fuel trims and their relationship to each other (where they should be normally, etc.)=

https://www.jaguarforums.com/forum/s...estion-144975/

For a different Jag but still applicable.
 
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  #52  
Old 07-17-2018, 02:21 AM
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Another (Different Jag once again, but still applicable) sort of a white paper on fuel trims. How/why they increase and decrease. This sometimes helps you look for the most common cause(s) =

https://www.jaguarforums.com/forum/a...rimer-rev2.pdf
 
  #53  
Old 07-17-2018, 02:57 AM
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I looked @ my torque log on 150 mile round trip. Fuel pressure was 54-56 constantly. Flat road, up/down a Mountain pass, freeway speed, in town speed.
 
  #54  
Old 07-19-2018, 12:20 AM
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Hi Dell, the fuel pressure reading shown was with the car off. I was just getting a feel for the Torque app. posted a screenshot. Anyway, there must be a logging feature in the app, but I've not found it.

Anyway, the Jag stalls now and again, and it has a weird miss in the electrical timing, most apparent at idle. The weird miss symptom actually seems to fade with acceleration. At 4K rpm or higher the motor performs good. I adjusted the TPS tonight because the engine still stalls. I found that on the yellow wire where I should read 1.65 V, I was reading 1.61 V. I corrected this reading by moving the TPS about its slots, but I was unable to check the other side of the equation. That would be the pink wire noted below.

quote:
Originally Posted by dwclapp Patterson: Those elongated holes in the TPS are to position it at the proper angle for correct output / signal voltage from the pink and yellow wires. With the ignition key in the run position and engine off, here are the DC voltages specified by Jaguar:

orange / yellow wire: 5 V reference input from the ECM
black / green wire: ground
pink wire: 0.74 V at idle, 3.97 V at full throttle
yellow wire: 1.65 V at idle, 4.20 V at full throttle
 
  #55  
Old 07-19-2018, 01:52 AM
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I could check the pink wire but I would need to check the high and low voltages on each wire, pink and yellow. That amounts to reading and adjusting 4 data points at once. It can be done, but you need to have really good access to the TPS and some leverage to rotate it and center it at will, then lock it down. In order to make this easier, I replaced the 5 point security bolts on the TPS with regular cap screws. They are M4 x 14mm. This way I can get a hex key into the bolt and tighten it at will when I get the right readings.
 
  #56  
Old 07-19-2018, 04:52 PM
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I just hooked up two volt meters to the TPS and grounded them on the battery. One reading voltage for the yellow wire, and the other reading for the pink wire. For the life of me I couldn't get them both to read 1.65V and 0.74V at the same time. It was either one or the other no matter how I turned the TPS. I even tried pushing/biasing it upwards, and to one side, which there's not that much slop in the mounting to get very far with the biasing effort.

This is my old TPS, came with this throttlebody that I bought new in 2012. I have a new off brand TPS at home, may try that tonight.

When is it okay to cry?
 
  #57  
Old 07-19-2018, 05:58 PM
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  #58  
Old 07-26-2018, 01:05 PM
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Is the TPS different for 2.5L vs 3.0 L engines?
 
  #59  
Old 07-26-2018, 06:02 PM
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No
 
  #60  
Old 07-30-2018, 11:45 PM
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