Trying to track down one of those every now and then issues. Our 98 Disco sometimes acts funny upon restart after its sat for a few minutes. If I drive it for a while, park it and then get in to leave shortly after it runs really rough upon restart. After about 30 seconds its smooths out and goes on down the road. Only does it every now and then but it drives me nuts, usually happens after I drive for a while then park for a quick bite to eat or to run in the store. Never does it if I wait more than 15 minutes to restart. Any ideas what it may be? It doesnt overheat, compression is where it should be and it was recently tuned up. 99% of the time it runs perfect. Also no codes popping up. Never given me any other issue than just being annoying but I'd like it to go away.

 

get one of these Buy Lisle Spark Tester In LIS19380 at Advance Auto Parts_____ and hold to spark plug wire when this happens, check for spark when cranking. No spark that comes back when engine cooled is usually CkP, the crank shaft position sensor. If it fails while engine off (heated up from block) it won't throw a code. Can also pour cold water on it to reset sooner. What is happening is sensor has become heat sensitive, and block heats up when switched off. PITA to swap, Rock Auto has them in the $35 range, be sure every nut and spacer comes off and goes back exactly the same order. Easier if plug in and let it dangle. Here's what it looks like inside, and what it triggers from (slotted disk on front of flywheel). Nose is carefully spaced from those slots flying by.

BTW - it will get worse usually and eventually not crank cold.

 

I've had the same issue going on for a while...if you want to read even more about troubleshooting check out Biernut (? I think) thread and you will see alot of things looked into trying to track down this hot-restart issue.

FYI - I think mine might be the fuel pump going out...but I'm really not sure. One is in the mail and we'll see. I thought it was leaky injectors, but couldn't get the fuel pressure gauge to confirm this, my pressure held great.

 

I put my reading glasses on and I think DIIB has a better point, since you actually get it to crank; see:

Engine fuel temperature sensor (EFT Sensor)

This is another resistive sensor. Located on the fuel
rail it measures temperature of the rail rather than the
fuel. The resistance varies with changes in
temperature. The signal is used to increase the
injection pulse time when undergoing hot restarts.
When the fuel is hot, vapourisation occurs in the rail
and bubbles can occur in the injectors. Increasing the
pulse time flushes the bubbles away, and cools the
fuel rail with fuel from the tank. The fault may not be
evident to the driver, there may be a hot restart
problem. The fault is indicated by illumination of the
malfunction indicator light (MIL) on North American

specification vehicles.

So if the fuel temp sensor is not doing the job, the injectors are not being cycled to remove the bubbles. Not sure about fuel temp on a D1 showing up on the OBDII port.

Sorry for wasting your bandwidth on the first post.

 

Fuel temp sensor.
Drivers side on the fuel rail, takes 10 min to swap out.
I had the same problem, it came and went, I finally got a trouble code for it, replaced it and no problems since.

 

Right on thanks guys I was worried it may have been more serious. It's only done it a few times but it always seems to act up at the worst possible moment. Looks like their about $120 new, would I be taking a risk snagging one from the junk yard? All sensors at the place I go are only $7 so I might grab two and hope one works. Is there any way to tell for sure if one is good or bad?

 

Salvage yards are a great resource if available, you may find some other parts that are worth putting on the spares shelf.

It is a simple resistor sensor. Will most likely be open or good, take a meter, should be able to probe before removal. If you see a nice looking MAF (check prices on a new one of those for a D1 and it will get your attention)....

Here's a page from one of the overview manuals that has a resistance spec, note that the original type up was not reviewed by an electrical person and used a capital W instead of the omega symbol for ohms. We don't need many 23 kilowatt sensors on Rovers..... would take a honkin' battery.

 

Get 2 from the junk yard.

 

Cool I'll be making a junkyard run soon so I'll grab a couple. I find it so tempting to stock up on things considering the prices, radiators are a whole $30 and the MAF are under $20 IIRC. Went last week and got a factory brush guard, hood release cable and a few other misc things. Was expecting a nice bill from the guy at the checkout and was surprised when my cart full of stuff only cost me $30.

 

Be sure to flush old radiators, which may have set up with dried gunk in the bottom - some yards cut hoses and drain antifreeze, so they start drying out from that day. Also be sure the oil cooler on a D1 radiator is not obstructed (I have a T shirt for that one).