My 2002 Discovery 2 started to have very poor idle and stalling about month ago. Engine does not get overheat. With the help from redrover and fery, I was able to get a diagnostic report on the condition of the engine. See attached report for your review.

Please let me know what you think. I need all the help I can get to have it back on the road again

Thank you

 

Have you tried unplugging the MAF and starting the car to check if the faulty idle + stalling is persistent?

 

Start with the maf plug and unplug etc like mentioned above. You should clean it too.

My order of diag would be.
1. Clean maf, check plug, make sure there are no air leaks after the maf (loose clamps etc)

2. Check for any vacuum leaks

3. if that’s good, check plugs and wires on those cylinders that are misfiring

 

Most of those are generic fault codes that aren't providing much detail except for telling you that you have misfires. The "Rough Road Signal Implausible" is often caused by wheel speed sensor issues, so that's not the cause of your misfires.

 

1) MAF was cleaned with MAF cleaner;
2) Plugs were clean and resistance checked and re-gapped.
3) IACV was removed and cleaned and put back.
4) Throttle body was removed,,cleaned and checked with multimeter and put back

After all the above work were done, Car still idled poorly and stalled

5) spark plug wires are to be replaced with brand new STI wires this Saturday

Will report back how engine is running with new plug wires this coming weekend.

Major concern: as pointed out by Redrover, two catalyst damaging misfire (indicated on the diagnostic report) on two adjacent cylinders could be a head gasket problem? eventhough engine is not overheating at this time?

 

Whenever you clean, MAF/IAC, or replace them I highly recommend resetting the Adaptions. It puts everything back to spec & then the engine will "learn" from the new or cleaned hardware.

 

TPS was never removed from throttle body. My car is an old 2002 D2. Do I need to reset it? If it needs to be reset, how would I do that?

 

On the misfires…. You COULD have a leaking injector or a leaking head gasket that is fouling those plugs.
But that alone wouldn’t stall the truck.

Your truck dies right?

 

You have two separate things going on there. The rough road signal is part of three amigos. Unplug the maf and see if 5&7 go away. If not, swap the plugs on 5&& with 1&3. If it does not follow, swap the plug wires with 8 and 6. If that does not cause it to move, swap coils left to right.

I think you likely have bad maf AND bad plug wires.

 

My truck has poor idle and stalls when foot on accelerator.

My new set of STI plug wires arrived but they tuned out to be all bad. I measured the impedance or resistance of each wire. One wire was over 13K ohm, and another one was 11K ohm. I ended up returning the STI wires. I am placing an order for a Bosch MAF but it wont arrive until next Monday because of the president day holiday. I am suspecting that the misfires came from both the bad wires and bad MAF. I dont have much data until a new MAF is arriived. I am going to use my other set of NGK wire and their impedance is very good. Each wire is below 1K ohm.

Questions:
1) Is there is a method and/or a special tool to remove and install new plug wires??? It is a super tight space to use my hands and fingers to remove and install plug wires to and from the coil packs.


2)I am thinking about relocating the two coil packs to somewhere else convenient and reachable on the engine
Where are the ideal locations on the engine for relocating the coil packs to? I believe the coil packs must be secured on the engine or manifold or plenum or valve covers and not on the inner fenders.

3) how to reroute coil pack wires in wire looms so that plug wires do not cross over from one bank to the other. I want plug wires for each bank stay on its own side, passenger or driver side.

4)Where can i get the the male plug for the existing male connector/ Or which vehicle model have this type of connectors (male and female) that I can get from in a pick-a-part wrecking yard

Thank you