Many of you know of my months long struggle to figure out my rebuilt D1's random misfires codes and many of you have graciously offered much help. Finally I can say it has been cured and hopefully this helps someone else in the future.

The codes were P1313, P1314, P0300 and occasionally P0304 and P0307, all relating to random misfires. The engine had just been rebuilt though and ran great. I tried everything I, anyone else, google, or GEMS manuals, etc suggested with no luck.

I'm adamant about doing as much work myself as possible, but in desperation decided to take it to a shop about 35 minutes away with an autologic system to see if it would reveal any clues my ultragauge hadn't. However, on the way there the engine starting cutting out intermittently and the cruise control shut off repeatedly. I immediately looked at the ultragauge and noticed the MPH was shifting erratically between 50 and 130 MPH so I immediately knew the VSS had gone faulty. When I barely made it to the shop we replaced it. Not only did it fix the immediate issues but it also fixed the misfire codes.

My guess is the VSS was starting to fail but only at tiny imperceptible intervals that I couldn't detect and no VSS code was set for.

So if you're having persistent unexplained random misfires, don't ignore the VSS!

EDIT: NEVER MIND. They're back

 

Also, Allmakes VSS suck. Buy genuine for this one. I was actually going to replace it for the hell of it months ago, but I dropped it from barely 3 feet and the casing split open and all the guts fell out. Then I could't bring myself to buy another when I doubted it would be of much value.

 

I'll keep your travails and fix in mind if I ever come across similar symptoms (several customers). Would love to further find out what exactly was going bad in it's circuitry. Your should now feel the complete difference in the motor rebuild. Do you still have the old VSS?

 

What codes would a VSS set? BTW ET, great job, as usual.

 

I guess I'll have to put a speedo guage on my UltraGauge. The regular speedo doesn't show anything unusual - I guess ? Good info, thanks.

 

Congrats on winning a hard-fought battle. Been reading about your struggles and happy to hear the VSS fixed it.

 

congrats ! on figuring it out !! the Rover Gods were on your side by having that happen BEFORE the guys at the shop were turned loose on it !

 

I also am glad to hear you finally resolved that issue.

Mine gave me similar but mostly 1336 code randomly until I did a thorough cleaning of the intake plenum. No codes since then.

I am down to fighting some gas seepage where I used rubber fuel injection tubing to connect to the replacement fuel pump that I got from RN a few years back. Tubing works fine for a while then either develops a rupture or swells just enough to get a little leakage.

It seems that each piece of tubing varies slightly, 5/16 is too big 1/4 fits but has a small blowby, the clamps that are available suck... the list goes on. I hate that straight piupe coming off the fuel pump and cannot seem to find a decent adapter.

I'm going to contact D&D and see what they may have. If that doesn't do it, then I am taking it to an industrial hose place in Pittsburgh and get something made up.

 

Someone please delete this thread

 

Spoke too soon eh.................

At this point it's important to ask; What hasn't been replaced? It should be a short list.

I have no Cats and I have zero problems with four O2's so I could make an educated guess that it's not that.

Is your ECU original?