Hey guys,

I’m having a problem with my 1998 Discovery 1 4.0.
I have replaced the following:
TPS
Mass air flow sensor
fuel filter
plugs and wires

The truck runs pretty good, but after I drive it for a while and try to crank it back it runs rough for a little bit. It seems to clear up, but I would love to find out why it’s doing it.

I received this information from my cheap scanner.

Cold crank
Short term B1=-8.59
Long term B1=1.56

Short term B2=-6.25
Long term B2=1.56

Warm crank
Short term B1=-4.69
Long term B1=2.34

Short term B2=-2.34
Long term B2=2.34
Long term B2

I’m getting the following code:
P1193

Is there a way to tell if it’s a cat or 02 sensor?

Thanks in advance!

 

P1193 is a downstream sensor fault. It does not change the air fuel mix but simply reads whether or not the upstream sensor is functioning.

Try to get some eyes on the crankshaft position sensor and the wiring to it. Wires and sensor are often found to be compromised by heat damage. This could be the cause of your trouble. The sensor is on the drivers side of the engine where it connects to the bell housing. Basically the mirror image of the starter motor on the driver side.

 

wow that is a lot of parts to replace - that is $2k in parts

hope you get it sorted out before it bankrupts you

 

I'd also yank out the ECU and check it inside/outside for corrosion.

 

Does your code reader give you pending codes?

 

Thanks for the help guys. I have already replaced the crankshaft position sensor. I will give the wiring a better look to make sure it's good and clean. As for the money spent it really hasn't been that bad I enjoy doing all the work myself. I was just doing a really good tune up before I started ventured out too far. It seems to do great around town. It's just after a 30-45 min trip it has the stumble when I try and crank it back.

It seems to run really (strong) after I run some seafoam through the intake, but then it starts to sorta bog back down again. No bad, but it seems to be noticeable. Maybe I'm being too picky.

 

Throw some more grounds on it. Block to frame, body to frame, frame to battery. Use a decent gauge. I added one from the left front shock tower area to the p/s area on the block. Cured a few, wee gremlins.
How are your vacuum lines?
I replaced the crank sensor on mine (it was quite the saga) the wiring was toast. Ended up rewiring from up top all the way to new connector. Put some of that fancy shielding used on thermocouples over the wires even.

Kinda sounds like you have a heat-soak issue.