Good day distinguished gentlemen (and any lurking ladies),

Previously on FML, my friend who WAS watching my car in back in the States cracked the infamous crank case breather hose and melted my MAF Connector: MAF Wiring Harness Melted - Jaguar Forums - Jaguar Enthusiasts Forum.

Currently on FML (FMJ?), a more capable friend has been working to fixed what turned out to be a much more complicated issue. New wires were spliced in and a new(used) MAF was fitted just in case. Put it all back together and very rough idle and supercharger making clunky noises. Good idle with MAF disconnected. Did a Battery Terminal Hard Reset. No change. Tried the other (original) MAF. No change; rough idle. Checked spark plugs. Minor oil leak and some decent fouling(6 year old Denso Iridium Twin Tips). Replaced with NGK 96457 Ruthenium Spark Plugs. No change; still rough idle with either MAF connected. Cleaned MAF. Reconnected. No change.

I'm not sure if there is a relay or fuse we need to check, order a new ECU, or perhaps both MAFs were bad this whole time,... I'm sure melted wires aren't good, but if anyone has any good ideas, they would be greatly appreciated!

Engine Code was read as P0112 which I believe is the following:

• Faulty Intake Air Temperature (IAT) sensor
• Dirty air filter
• Intake Air Temperature (IAT) sensor harness is open or shorted
• Intake Air Temperature (IAT) sensor circuit poor electrical connection

Should I buy a brand new DENSO MAF or could the wires still be causing a problem?

Cheers!

 

Have you gotten any codes?...please list if so.
Check the pins on the MAF, there have been issues of them pushing out.
Have you checked the breather connection at the cover for any obstruction?
Did you splice in that harness that xalty recommended?...I would check the splices and verify connection. I like using these because all you need is a heat gun... ...a lighter will work, but can burn the seal ability and is not consistent.

 

If this started as the temperature turned cold, might be a bad temperature sensor: new cross over pipes come with new sensors.

 

My buddy pulled a connector from a junk yard X308. I think it was N/A, but he said the wires and pins lined up,... He soldered them in and wrapped in elecrical tape. To be honest it looked like crap, but should've still worked. I can post a pic,...

 

Dis gud?

 

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I don't think it was the temp as it doesn't change much where the car is.

 

The code was P0112 as stated in the original post.

 

My bad on the code inquiry, ...habit to do so since so many don't.

Some heat shrink would of been nice, way better shielding than tape. But at least he soldered them, kudos on that effort. Here's a cheaper version of what I posted earlier for solder joints...
By chance, was that new (used) MAF from the same place he got that new connector? If so, then yeah, I'd be looking at a new one (not used)...if you can't find Denso, ..Delphi makes some descent components.

 

I think I would change the temperature sensor! Solve P00112 first. Most of the time that plastic crossover pipe is pretty close to failure -- new ones come with a new IAT sensor. They are cheap too.

 

My apologies. I'm not sure what part you are referring to. I thought the air temp sensor was in the MAF.

 

The temp sensor is in the crossover pipe in front of the thermostat; from those wires at the MAF, follow one back towards the radiator and thermostat, it will be coming from the temp sensor in the crossover pipe.

 

Google X308 IAT sensor and crossover pipe; you will see a picture of the piece. I

 

Jim, the IAT is the intake air sensor, located in the MAFS. The water temp sensor is located in the crossover pipe.

 

Oh yeah, my buddy has been awesome. I was referring to the wires looking like crap. They look old and brittle. Thank you everyone for helping me try to figure this out. I think I'm going to get both a new connector and a new MAF. I think that's probably the best bet, but one other thing I'm questioning is whether or not it's possible I'd need a new ECU,... If the MAF wire's shorted, could that have fried anything else?

Thank you!

 

Code P0112 points to a problem related to IATS. As the second MAF shows the same problem, it is unlikely that the fault is in the IATS itself. I would check the continuity of the wires (Black/Green and Blue/Purple) to the relevant ECU pins (see the attached PDF engine management diagram). The code suggests an open circuit in one of these wires.

 

Back-fed shorts can toast many things, one of the only ways to tell is metering.

 

What's thr best way to test this? If the circuit is open, what will I need to replace? The ECU?

 

I have the coplete engine (and rest of vehicle) wiring harness in my garage as well as a S/C MAF and even ECU. PM me if you need anything

 

First, verify that the wires to your MAF connector are as shown on these pictures:

 

Buddy tested the wires and sent the following:

Running continuity: between UP and BG Abt 3k ohms. So no opens in those wires. GY-WU 186k. GY-BY 186k. BY-WU 182 ohms. So no opens or shorts. Black wires connected to ground. With the power on UP has 5 volts. WU-12v and GY-21miliv. Not sure what the numbers are supposed to be but certainly no opens or shorts in the wires. Strange.

So I guess I should buy an ECU and/or MAF?