Cheap and easy way to check for air leaks: elm327 or other cheap OBD tool with live data and look at fuel trims.

 

I hope you don't see any more problems. It seems that when it rains it pours, so to speak.
Batteries do go bad sometimes as do coil packs. I wanted to be sure you understand what might be causing your problem and how to check for a fuel supply issue. Best of luck...

 

I had the 0174, 0171 codes and cleared them and got a p1000 code. I cleared that one as well. Haven't driven much since then but I think it will come back as I haven't found the leak yet! What is the p1000 code?

2005 3.0 stype

 

Exactly what forum Search is for!

Also, the codes PDF / JTIS.

 

This link should help

Link http://www.jagrepair.com/JaguarSTypeElectricalOBDIIcodes.htm

 

Hi everyone,
(2004 Jaguar VDP, 4.2, 8 cyl)

I am having engine fault for Bank 1 too lean P0171 and P1111. a year ago I got the same massage and it was resolved after cleaning MAF sensor. This time that did not help. Someone on another thread still suggesting to replace the MAF sensor and I am keeping that in mind. My question is, if MAF sensor (or any other common parts like fuel filter) is bad, wouldn’t I get faults for both Bank 1 and Bank 2? What should I not look into if only one bank fails?
No visible air leaks, cracked hose or hissing sound. (no smoke or vacuum test is done yet)
To further investigate this problem and making sure my injectors are working correctly I tested them and got myself confused. Using universal NOID light, I get the light pulses on bank 2 injector connectors and when I disconnect any of them to test naturally the engine runs rougher. But, I get no light blinking when testing any injector connectors on bank 1 and disconnecting any of them does not affect the engine performance.
At the same time, with the stethoscope, I can hear all bank 1 and bank 2 injectors with the same audio frequency. So, if I get no light blinking on bank 1 injector connectors wouldn’t that mean there should be no firings on bank 1? That is where I get confused!
A separate question I have is how to reset engine faults on this Jaguar. I can reset engine faults on my Toyota and Lexus via my handheld code reader or by disconnecting battery terminal but neither of these techniques are working on the Jaguar!
I appreciate any comments. When commenting, please keep in mind that I am somewhat mechanically inclined and often fix my own cars but I am not an auto mechanic.

 

P1111 is a good one!

If the car is operating correctly that code should be present and shows the emission readiness monitors are all in the ready state.

You should pass inspection.
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Look at fuel trims on both banks. Hot engine, parked, at idle & 2500rpm.

If they're similar then you can have a leak that hasn't managed to flag P0174 as well.

If they're unalike then it's not the MAF or anything else that's common to both banks.

Any working OBD tool can clear the codes. P1111 will change to P1000 and you'll have no OBD monitors set. Any tool that won't is broken, simple as that. You probably should NOT clear them till you know what's wrog and have fixed it.

 

Friend had this issue with his 02 325i. It started to just throw codes then it started to run very very poorly if at all. With bmw it also throws transmission codes and puts it in limp mode. I'd say replace the maf amd clear tje codes. there is a good chance it is the issue.

 

There's a good chance that costs a lot and won't fix it. This is not a 325i.

OBD is cheaper and gives useful data. Swapping parts is a crapshoot and way more expensive.

 

While not a bmw there are similarities between the issues. We confirmed by looking at live data on the fuel trims it was low causing the issues. You can also unplug the maf and see if you notice any idle differences. Had a volvo do the same was the maf as well. I'm not saying go buy a maf but it's where I would start looking. Do you have an indy shop close?

 

Why would using OBD not be a much better and cheaper idea as I suggested? elm327 starts at about $10 and you get a tool for many cars over many years.

 

Found the culprit! Under the engine cover is it the crankcase vent hose? Had to take the hose off and look underneath, see photo.

 

My check engine light is on and I get the performance restricted warning occasionally as well. I recently got on OBD and here is some of the information I got out of it. I don't really know what I should be looking for but the codes I have are 0171,0174.

Performance restricted message not indicated.

Bank 1

Stft idle/750 rpm = 0 to -1%
Stft 2000rpm = jumps to 20 and comes back down over time. Will even go negative.
Ltft idle = 0%
Ltft 2000 rpm = 14%

Bank 2

Stft idle/750 rpm =0%
Stft 2000 rpm =jumps to 20 and comes back down over time. Will even go negative.
Ltft idle = 0%
Ltft 2000rpm =15%

FP

Idle= 55.7

Intake man pressure

Idle=9.4 to 9.7Hg
2000rpm =7.7 Hg

Intake air temp

127.0 f

Maf flow rate

Idle=.5lb/min
2000rpm =1.1lb/min

 

Attached is a list of all the codes and what would cause them.

Link http://www.jagrepair.com/images/Auto...tos/P20003.PDF

The codes are lean codes on both banks so I would first look for an air intake leak between the TB and the MAFS. Have you done any work on your car?

 

Do you have any suggestions for where and how to check for leaks? Haven't done anything major to the car and nothing recently. Do the fuel trims suggest that there is a leak?

 

See if this helps

Link http://www.jagrepair.com/images/Auto...otos/P0171.pdf

I use Throttle Body cleaner. When you spray it near a vacuum leak you will see a change in the idle of the car.

 

For me, those are very odd fuel trims!

Air leaks usually show far more at idle (there's not much air getting past the MAF so the leaking air has more effect).

I'm tempted to a non-air leak cause. You've similar effect on both banks so something in common - like a misreading MAF. It might clean.

I don't know why the STFTs change during the revving. Cats heating up... sure... but not sure the relevance.

I wonder if fuel issues (blocked filter, lazy pump) could cause this? Anyone have ideas?

 

First of all, an engine running lean does not mean that you have an intake or air leak. It means the mixture does not have the proper ratio of fuel to air. I spent hours hunting for leaks, when in fact my fuel pump was failing...for about a year ! I highly recommend going to Autozone and borrowing their fuel pressure gage. You can screw the gage on to the shrader valve on the fuel rail and check the fuel pressure in their parking lot. It should read about 34lbs on idle and increase a bit when you race the motor. My fuel pressure was 24 lbs. This caused the computer to try to add more fuel...which caused high fuel trims until finally a problem code was sent and my car went into restricted performance mode. I could drive 500 miles sometimes before my car would throw a code...other times , only 100 miles. One of the problems with the Jaguar fuel pump, is that the electrical connector is poorly designed. It is barely large enough to handle the current. My fuel pump connector was melted where the wires plug to the pump. The replacement fuel pump connector had pins twice as large, which means a lesser chance of heating. This may not be your problem, but it only takes 5 minutes to check fuel pressure. I wish I had tried this before spending all that time looking for leaks. Also, one mechanic I spoke with wanted to pull the intake manifold and replace the gasket...never let someone do any repair until they confirm that is the cause of your problem.

 

Yes it is a fuel to air ratio and we can only go by the codes. We presently have P0171 & P0174 lean codes that is related most of the time to a vacuum leak or MAFS we do not have a P300 or a P1316 leading me to a fuel issue.

My first step would be to check for a vacuum leak, clean the MAFS reset the codes and see what takes place. No harm in testing the fuel pressure if you wish but for now you need to let the codes guide you.