My Disco has an issue with stalling at low rpms especially when cold but also stumbles when hot. At highway speeds it runs normally (above 1500 rpm).

The code reader is printing out 1316 and 1447 along with a 0300 randomly.

I know the fuel pressure, vacuum pressure, throttle position sensor, idle air control valve, mass air flow sensor, fuses and purge valve are in normal working order.

Any input would be great!

 

Today the rover wouldn't maintain steady acceleration. The tach danced and the engine lost power and then momentarily gains it back. I'd really appreciate any help, otherwise its off to the stealership.

 

When is the last time you have tuned it up? Spark plugs AND wires? If you have a short, you will have intermittent issues. This can normally be identified by "misting" the wires in a darkened location. You will see the short.

 

I haven't checked the plugs or wires, I'll do that today. Is there anything else that could cause something like this though? Has anyone had an experience with a bad fuel pressure regulator or thermostat and symptoms like this? BTW its a 99 disco 1 with 100,150 miles.

 

I believe it is an issue with the wires causing mis-fires and raw fuel being dumped passed.
Has your fuel pump been replaced?
When was the last time the fuel filter was replaced?

I would start with the wire and plugs (check for fouling etc....) replace wires with MINIMUM of 7mm wires, the "standard" ones you get from Autozone, Advanced, Pep Boys etc.... are not capable of handling the charge for any period of time. They WILL cost you more, however, the PLUGS you use can be the $2 Champion standard plugs. I had MANY problems trying to use "split fires", the "quad tops", Platinum etc...
Get good 7mm/8mm wires, standard plugs - and ONLY premium fuel 90+ Octane (92, 93 Octane) <-- this is one thing that WILL kill your Rover slowly, but definitively. Many will disagree, some use only 89 - but the PO for my used 89 - and bumping up to Premium and getting good wires and plugs eliminated the "rebuild" HE was getting ready to do - as it was unnecessary.

 

BTW - reading your initial post, I thought the Fuel Pressure was already checked and found to be running well, so I didnt not even give the regulator a thought as I assumed it was eliminated based on the pressure findings.

 

The wires all check up based on a simple resistance test. I might end up checking the alt this weekend if I get a chance - easy enough job with the time. And I just changed the fuel filter today - the fuel pump is newish too. It started spitting black smoke when I started it up.

 

I still think you have a mis-fire occurring. They might pass the resistance test, however, lower level wires cannot handle the charge that these engines take - and they short right through thinner wires. could be a fouled plug as well.
Good luck!

 

One cheap thing to try is the coolant temperature sensor. If you really wanted to test it, there is a way by checking the resistance at different temps, although I don't have the values. Or you could replace it for a few bucks and 5 minutes. The plugs and/or wires sound like a possibility, but it seems like you would get a specific cylinder number misfiring. Have you looked at the plugs ? I'm assuming they are all the same shade of carbon black from running rich ? Have you tried cleaning the MAF with MAF cleaner ? It's easy and cheap. Just use MAF cleaner spray. I think CRC makes it.

 

If I haven't had the ecu reset at the stealership after my fixes, would that be a reasonable cause to a continuation of the issues? By not reseting the computers' stored sensor values will it continue to run on my previous "limp" mode?