Well, here goes...

2003 Discovery II 82k mi.

I knew my crankshaft position sensor was failing due to my truck being almost impossible to start. Fine. I correctly replaced it (triple check orientation of the plug, etc.) tonight and I sit here and type this will still greasy hands.

After replacing it, the truck fired right up and ran at idle like a dream. In fact, better than I can remember. I cut it on and off a few times and forced it to hold a rev between 3 and 4 thousand rpms. No problems there.

So I throw her in drive and take out for a quick roll around the block.

[:@]

Once I get to the shift point in second gear, the engine starts pulsating. It felt a lot like hitting the top of a rev limiter. I back off it and slowly creep back to the house.

I tinkered around with and inspected a few things then gave it another go. This time, I manually shifted from 2nd to 3rd. At the top of each range I was experiencing the same thing, but it did shift without problem.

It doesn't seem like a transmission problem. In fact, oh God don't let it be a transmission problem. The shifts are fine, not hard or jerky. It also doesn't reach the shift point and then rev up really high before shifting.

I just had my buddy come by with his OBD II scanner. He has a good one (he's a mechanic) and it didn't pick up any stored codes. None of the dash lights are on. There was no puddling or excess fluid underneath the truck and it has been sitting in the same place for 4 days.

Any ideas? Any suggestions?

Add: For those of you getting ready to change your crankshaft sensor, pick out a few choice words to yell. It's a pain in the ace to get to.

 

I LOVE your signature. Thats all I got.

Have you checked your battery and alternator for proper voltage? The transmission is computer controlled and low voltage can mess with it.
Just a shot in the dark there, doesnt sound like that is the problem but who knows.

 

I ruled them out, since both have been replaced within the last 6 months. I also payed very close attention to the lights, which do not dim with the pulsing.

I figured as much, but the problem consists whether in regular or sport transmission modes.

 

Well good luck to you and let us know what you find out.

 

On to plan 2:

My friend the mechanic called me back and told me that sometimes cars store "soft" codes about the engine. Those being something the engine doesn't consider a problem, but more like a hiccup. The codes are erased once the problem ceases to exists or they are escalated if it blows out.

His thoughts were that my replacing the crankshaft sensor has messed with the injection timing. The engine hasn't "learned" that a new one is in there yet. So right now, it's sitting outside with the battery disconnected. I guess it's a long shot, but worth trying.

Anyone with a replaced CKP had to get their computer reset or other?

 

You might need to just drive it until it resets itself. Ask your friend what he thinks about that.
Others have replaced it but I do not remember hearing about any problems, not that there may not have been any.

 

No go. It's still pulsating.

HELP!

 

I was thinking that it needed to relearn the new input also.
I see that your friend was thinking the samething.
I hope thats it give a day or two.

 

I also think that you are going to need to drive it for a few days.

 

Update:

I drove it to my mechanic friends house and we took it around for a spin. It never cleared up.

When we got back to his house, I could smell it. This b!tch is running rich.

I had him re-scan the ol' girl and I *finally* got some codes.

P0103
P1590
P1884

P0103 & P1884 are related. The first is the MAS and the second, transmission. Apparently the MAS needs to be replaced (will clean it tomorrow) because it's forcing the engine to run rich right at 2k rpms, or the natural shift point.

P1590, I'm sorry to say, will probably never leave me. Fugging TC.

I'll update when I've flushed all the gremlins out.