Happened again tonight so it's definitely not the fuel pump connectors. Can anyone advise where the ECU is? I think I'm going to take Disco-Mike's and Danny Lee's advise and see if my seals are bad on it.

 

P0340 - Camshaft Position Sensor Signal Error Fault

P1316 - Misfire Excessive Emissions Fault


Get the CPs wiring/connector ironed out and your misfires should abate.

Grab a new connector for the fuel pump preferably a GM style waterproof.

 

The ECU is on the inner fender, passenger side near the washer fluid bottle. You should have a black cover over it, and a piece of weather strip on the lip of the fender that the hood closes against. The strip was put in to help shed water away from the ECU. Do not seal the ECU completely, it has a breather that must remain open to keep it from forming condensation. Don't go there yet.

The RAVE states that a faulty CPS would likely go undetected if not for the code. If you look at the schematics you'll notice the CKPS is closely tied to it. The CKPS has no code. What you are describing sounds more like a CKPS going south to me. Very difficult to diagnose unless you are 100% sure the CKPS is good. Autozone sells the OEM Lucas in their Duralast box for under $60.

Have you taken a good look at the coil pack and ignition wires? Start it up and take a look in the engine bay on a dark night with no lights on, if there is spark jumping to ground through a wire or a bad coil you will see it, if you see nothing use an old windex bottle to spray the coil pack and wires to see if you can get it to faulter.

The emissions code means nothing and will stay away once you fix the misfire. The fact that it stops misfiring after running for a few minutes makes me wonder if the engine heat isn't drying out moisture from the coil pack and stopping the misfire.

 

What year is yours , if it is Pre-AEL you can get a whole fuel pump assy for around a hundred bucks! If you really need one, have you checked your fuel pressure at the schrader valve?

 

Just got the ECU out after a struggle with the washer reservoir (one of the nuts would not come off of the bolt). Opened up the ECU and everything looked good on it. There were no signs of moisture ever being inside the unit (looked brand new). Going to pick up a CPS and hope to God I can install it myself. Tried to test the coil packs and got nothing. It should be noted that the first thing I did when all of this started was replace all of the plugs and wires... no dice.

98 Discovery I LSE