03 Disco - Sputtering Idle/Low RPM

stonychavez

New member
Apr 10, 2019
2
0
Texas, USA
I recently purchased my first Land Rover as a project build I will be doing. It was an 2003 Discovery II, and I have full service records for the vehicle. It only had one owner from 2003 through 2017 and accumulated 118,500 miles. In 2017 through 2019 it changed hands with (3) dealerships and only accumulated approximately 600 miles in 2 years.

When I purchased it ($3,500.00) it had the service engine soon light on and I pulled codes on it which revealed (3) codes:

MAF Sensor Fault
Secondary Air Bank 1
Secondary Air Bank 2

I pulled MAF Sensor and cleaned it thoroughly, check compressor for secondary air to ensure it was operating properly (it was) and then began checking air lines. That is when I found that a previous mechanic had used an improperly sized coupling to attach the secondary line to the intake manifold causing the connection to slip in and out. I corrected that and then reset the codes. I ran compressed Sea Foam through the intake to clean out the system (not a lot of smoke came out the exhaust leading me to believe the system wasn't neglected and in good shape), I then was in the process of running my 3rd tank of seafoam conditioned fuel through the system (approximately 8-9 days later) when the service engine soon light came back on. During that time frame I started to notice an intermittent "sputtering" with the engine. It shows up after the vehicle has been driven for 5-10 minutes and only when the vehicle is in drive at low RPMs. If I put it in neutral, the sputtering stops immediately and it doesn't occur (or isn't noticeable) when I am driving or go over 1,500 RPMs. I pulled the codes and received the following:

N/A - Permanent Voltage Supply Fault
P1000 (62) - Emission relevant Misfire Multiple Cylinders
P1000 (56) - Emission relevant Misfire Cylinder 7
P1000 (80) - Secondary Air System Fault Bank 1
P1417 - Secondary Air System Fault Bank 2

My current plan is to service/inspect the following:

Pull sparks plugs and inspect/clean/replace as needed
Pull and clean idle control valve
Re-inspect all vacuum/air lines

Any guidance or previous experience/lessons learned would be appreciated. I have inspected the wiring to the plugs and they look brand new, leading me to believe previous dealer has already attempted diagnosing/fixing issues. Is it worth replacing fuel injector?

Any help would be great, I will update as I trouble shoot, thanks.
 

stonychavez

New member
Apr 10, 2019
2
0
Texas, USA
0 Responses?



I figured out the P1000 codes are more than likely related to me disconnecting the battery to wipe the codes. Once I changed the wires/plugs, everything has been running properly.