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The IACV bolts are tiny and loctited on. If you don’t heat the bolts before attempting to remove them, you will snap them. You may want to prepare yourself with some helicoils or timeserts.
Thank you Vee. I had already encountered these screws before your note. Yeah, they were tight. Are they 5.5mm? My 5mm was too small and my 6mm was too big. Ended up using a 7/16 WEHA nut driver. Backed them out very slowly when I noticed how tight they were. Interestingly the new unit was identical except that the screws they provided were too large for the existing mount holes. We ended up using the old scres again. Went in as slow as they came out.
Anybody know the size/thread of the exhaust manifold to downpipe studs part #EAC003823? Googling the part# hadn't yielded any details. Thinking of putting on brass nuts, but need to know what size.
Anybody know the size/thread of the exhaust manifold to downpipe studs part #EAC003823? Googling the part# hadn't yielded any details. Thinking of putting on brass nuts, but need to know what size.
Hi All, Just bringing you the latest... Here's where we're at. We replaced the O2 sensors (checked and double checked their positions vs color codes on the wire harness connectors, B1 S1 Green, B2 S1 Brown, B1 S2 Blue, B2 S2 Red., Replaced the IACV, Cleaned the MAFS. Sealed up a few exhaust leaks A lot quieter now. Thermostat sensor appears to be good. TPS did read .54V at idle last week, have to re read that. Was still sputtering this morning after it warmed up (original problem). Then replaced the crankshaft position sensor. The sputtering when accelerating seems to be gone, But there is still some light sputtering when idling. Also it appears to be idling high at about 800 in park, 650 in drive according to the on board tach. Unfortunately after about 30 minutes of running the car throws a BLINKING P0300 and P1314. I've looked these up and see may instances on these forums. P0300 is a misfire (unknown cylinder) and a 1314 Misfire Catalyst Damage Fault Bank 2. I double checked the o2 sensor locations again, should be good. We still suspect a coil issue and we're still waiting on some good coils. Might the P1314 point to a bank 2 problem (maybe a bank 2 coil issue)?
Haven't replaced EGR Valve, TPS of MAFS yet. I will try and get fuel trim numbers when I can.
Warm engine, idle should be at about 580rpm. I could see it at 650 when it’s cold. That’s in gear, by the way.
In Park, idle should be at about 700rpm. Warm.
Take a second look at your TPS. Should be at 0.60 volts. 0.54 seems very low. Not that it couldn’t have been reset to a different level at some point, but I’ve not seen it that low before.
You sure you have no vacuum leaks? The only one that’s really hard to find is at the intake manifold. I had a leak there that multiple garages (and me!) could not detect.
I did pick up a new ODB2 reader that I need to learn to use. I'm not certain how accurate the in dash gauge is. It's not an expensive unit but was recommended by that Scotty Kilmer fellow on YouTube. It should give us a more accurate reading than the dime store unit we have now that's basically just reads and clears the codes. We'll probably need to get the misfire corrected first as it may be throwing the idle off. My son says he can feel the rough idle (and misfire) from the drivers seat. Since it's his car he has a better feel for it. We did notice every minute or so the idle dips for a second and then returns to what it was before the dip. We weren't sure if this was part of the misfire issue or maybe the ECU trying to make an adjustment.. Or both. Once we get the misfire fixed I'll look into adjusting the TPS. Unfortunately I only have one day off a week to spend time on it, so it's been (and will be) slow going,
Vee, in another post you gave some voltages that should be seen at the MAFS. How did you access the wires to get those voltages? I think it was Lady P who earlier on gave the tip of nicking the green/yellow wire over the fuel rail to get the TPS voltage. Would I have to do the same for the MAFS?
Thanks all for the assistance. I may not always reply directly to hints and tips here, but we do appreciate and consider all of them.
The MAF sensor connector when installed will have a return to the ECU signal on the center wire on the connector of 1.2 volts DC at idle and since it is present in front of you you can but a needle in the connector as the wire goes in
You may observe different readings of the STFT with different throttle settings when there is a problem not resolved , you may see it go from a bad value to a good value on throttle up
With a "" tight "" regulation system operating correctly a perfect target value of 0.0 % can't be achieved because of the increments of fuel injector pulse width time are too many to store in the ECU maps or data arrays
An example would be a commanded pulse width of 1 /100 of a second and the next pulse width of 2/ 100 of a second when the perfect pulse width would be 1.7 / 100 of a second
This is why a good STFT of + or - 3.0 % during all engine ranges is the best you can get
A bad STFT at idle can get better on throttle up and this breaks down into 2 reasons
The supply of vacuum source increases overcoming a vacuum leak and negating a vacuums leak as a factor
The amount and consistence of exhaust gas pressure overcomes a leak drawing in fresh O2 between cylinder firing as a "plug " of exhaust gas travels down the exhaust line
The EVAP valve should be closed at idle and you can test by blowing into the vacuum line
On mine this one vacuum line was missing as well as a cracked manifold
One thing not discussed alot is leaking wheel brake booster diaphragm and a safe test
DR. appointment while I edit this
Fuel in the vacuum line from the fuel pressure regulator and the manifold ?
Bad fuel can be siphoned out with a 1/4 th inch tube , at least on mine
Someone recovered there idle with a new main fuel filter and another by cleaning the EGR
There is a PID of EGR- _ Error which has a target value of 0 % as it is commanded to be either open or closed but I wouldn't expect the in service engine EGR to be perfect
The EGR has a follow up position sensor unlike the IAC to know its position
The EGR has a temperature sensor that should modify the injector pulse width along with the IAT sensor and can be calibrated like on post # 17 with the Jaguar document S801 PDF
In the all encompassing theory of Parker ( or Lady Penelope in the car''s name in earlier postings ) these Thermister sensors are feed energy to operate and if they are insulated by stuff the actual temperature it would " see "is higher then the fluid that passes it
A dirty connector or bad wire connection would be higher resistance and this would bias the sensors reading to a lower temperature which is opposite of how a old school thermocouple would behave
In some examples of the X300 the wire bundle can have corrosion on the wire splice points and would have to look at the wiring guide if the spesific sensor in question has a wire splice to inspect . I think off the top of my head the CKPS does
You can read them at the ECU connectors
ECU connector clean and on close inspection the sockets have both pinching tabs present to ensure connection or gripping
We yould do a gripping pull test in the airlines on this matter but we had the parts and tools to do that
Dedicated and separate ECU case ground wire installed ? There are other ground wires in the wire bundles
Cleaning those other ground points including the large woven engine block ground is recommended
I had an epic issue with a dip in idle every 32 seconds. When the car was loaded, headlights, air conditioning, etc. It was more pronounced, occasionally stalling the engine out.
It turned out to be a leak at the intake manifold gasket. Took three shops and boatloads of thrown parts before it was found. Some of these thrown parts masked the problem for awhile, but it always eventually returned.
WOW. Thank you. It will take a while to absorb/check all this. The fuel pressure regulator was replaced two weeks ago. We can try removing that vacuum hose and temporarily plugging it to see if there's any difference. The pressure is about the same as the old one (stays close to ~40lbs average). We had the ECU out last year and is was corrosion free, but it may come to us checking the continuity of the wiring. I don't suppose anybody makes a test connector to extend the wires out a couple feet? I remember it being a bit tight to get into the main connector after the ECU was removed.
Some questions:
Where is the EVAP Valve on the X300?
Just upstream from the MAFS there is a sensor at the elbow of the intake manifold. What is this sensor?
We installed a new intake manifold gasket, but we did remove/install the manifold a couple times. It's possible there is a crack in the new one. We installed it dry (no coating of oil or gasket sealer) since that's how it appeared when we originally pulled it apart. Is dry correct?
There are two sensors on the drivers side of the engine block that appear identical but take different connectors. One is just behind the starter and the other is in the same location but more towards the front of the engine. I was guessing they're temperature sensors. Is that correct?
Is there a way to verify the EGR valve is working? It's still original to the car.
To make sense of the vacuum hose routing there is a diagram on page 60 of the Jaguar S801 PDF
A one vapor canister system will have only the one on the left side fwd of the rear tire
A two canister system will have one on each left and right side
The EVAP valve is under the engine air filter and you can use a 9 volt battery to hear it click but unpowered I think it was closed which is your interest
There is a short hose connecting it under the intake manifold
An easy way to check it without removing it would be a 3 foot 1/4 inch clear hose like on a fish tank but much cheaper by the foot at the hardware store , 7 foot would be a good length to siphon the fuel tank , the glass recycle bins have the 1 gallon glass wine bottles and they are very cheap when its dark
The TB butterfly has 2 engine coolant in and out hoses that can posibly gets mixed up in connection between the 3 hoses
The cruise control hoses are independent and isolated from the engine vacuum hoses . The cruise control has it's own vacuum pump
The sensor in the 90 degree bend is the inlet air temp and mine was covered with a thick layer of oil breather residue
on the left side of the engine block you have 3 sensors , 2 knock sensors and a oil pressure or temp ( can't remember )
There is a PID of EGR- _ Error which has a target value of 0 % as it is commanded to be either open or closed but I wouldn't expect the in service engine EGR to be perfect
The EGR valve has a position sensor inside and you can read it's position with a simple meter on the ECU connector but a better test would be the engine running and nick the wire insulation as it comes over the fuel rail . The wire is Red / Pink color and the value is 0.7 volts DC for a closed valve
There was a Jaguar TSB to change to a different part # EGR and updating the ECU software to control it
You may or may not see a sticker on the ECU identifying if it has been done
Some have repositioned the throttle return spring instead of replacing it with the revised spring part #
How this TSB effects your idle is a question but I believe the EGR replacement was to satisfy the emission regulation people like in California
You may ( and that is a question ) just leave it totally alone and not have a performance effect on your idle
09-20-2021, 07:24 AM
