OK, I just got the Disco back on the road after replacing the crank Pos'n sensor as described in the 98 Disco sudden no start thread. I took the opportunity while it was in the shop to replace the shocks with KYB's and the front shock mounts with galvanized ones from Rovers North. There is another thread's worth in that job but I digress. Pulling it out of the shop, it was running like a bag of doodoo, and misfiring like crazy. It was running so badly that I only made it a 1/4 mile before turning back. It is now showing the P1314 misfire code. Strangely, it is also showing *pending* codes for P1447 Evap.can valve perf., P0451 Fuel Tank Pressure Sensor Performance, and more strangely, P1317 ABS rough road signal ground or open. That is strange because the ABS never worked and I have both ABS fuses removed.
I dunno if it's pertinent to the Evap codes, but I just sealed around the fuel pump mounting ring with silicone. It never fit right and was letting water into the fuel tank if you drove through a lot of water. I was trying to avoid that.
I'm not sure where to start here, because it was running perfectly before the crank sensor went. I put new plug wires and plugs in it a few months ago.

Any suggestions welcome. Thanks all!

Phil

 

The rough road code suggests that looking into your camshaft position sensor might be worth a shot. It might actually relate to the misfire as well.

 

I don't quite get the connection, but I'll try anything once. I know I bought a spare cam pos'n sensor last year, now I just have to find it. Thanks Walt!

Phil

 

I changed the cam position sensor and the truck still runs like doodoo. I'm starting to wonder if there is some sort of fault with my new crank position sensor. I just can't think of what else, it was running perfectly before. This is going to take some further investigation. And likely several ,

Cheers

Phil

 

Maybe loose wires or fuse? Capping off the vapor canister tube is easy to do as a test. Did silicon plug up the fuel tank pressure sensor? Some here have posted about bad crank sensors out of the box.

 

Thanks John. I don't know the vapor canister trick. I will check my silicone job on the top of the fuel pump, but I was careful not to go crazy with it. I've ordered another (different brand) crank sensor from Rock Auto and will try that. The new sensor I put in is an NTK.

Cheers

Phil

 

I'm talking about the vapor tube entering the intake plenum. Slide (pry) it off then put a cap on the plenum entry port.

A while back I put together a kit of small spare parts for when I take off into the wilderness. For one, I removed my working CKP sensor and put in a new one, NTK brand ordered from ngksparkplugs.com. The new one fit and works great. Now I have a known good spare.

 

Well, I seem to have a new problem that may have caused my misfire issue. I likely had an intermittent fuel pump relay causing inadequate fuel flow. The fuel pump relay is now kaput, no fuel pump at all. I have checked the wiring, and the FP relay (in the three relay black module next to the vapor can) has constant power, switched, and ground, but does not close. I took the cover off the module and can see the relays clearly.
It looks like I have to replace this relay module, but I can't find it listed anywhere. The Rock Auto listing just shows regular 4 terminal relays, and my usual suppliers (Rovers North, Rovah Farm) don't list it at all.
Does anyone have a source for this, even (perhaps preferably) used?

Thanks

Phil

 

Correction: I found the relay module at Atlantic British. $225 US shipped. I really hope this is a plug and play fix. Fingers crossed!

Phil

 

Well, new fuel pump relay module, still no fuel pump. The relay is not clicking, even though I have power where it's supposed to be. I'll have to dive into checking more of the wiring, but I'm rather flummoxed (and frustrated!) at this point.

Cheers

Phil