Did you replace fuel injector o rings?

 

You should only use RTV on the valley pan gasket around the water galleries and at each end of the rubber segments.
I use copper coat on any other gaskets, but no sealant.

 

I put new fuel injector orings on, and then the refurbs I got had new orings as well.

Is a vacuum leak at the plenum gasket common, or would it be an issues to re-use that metal gasket a few times?

Just trying to check off a few things.

 

I've reused the metal gasket in a pinch, but normally change it.

you can also put a thin film of RTV.

If you can tell a difference when spraying under the upper manifold it can only be upper to lower manifold gasket, injector o rings, or the valley pan gasket.

Do you recall any issues with that gasket, folded edge or the like?

 

Well my new O2 sensors came in. Swapped them out on my lunch break which cleared the pending P0130. I took it for another test drive and it felt good, acceleration was responsive.

Sure enough though, soon as I get back SES light is back on with the sticky P0308 code. At this point I must be performing one of the tests wrong. Unless anyone else has any other ideas? So starting over I'll recheck these:
1. Verify spark with inline checker
2. Inspect the plug for power washing/verify no coolant in oil?
3. Verify injector (any way to verify fuel is reaching chamber? smell the plug?)
4. Verify compression

What's really confusing me is the single misfire as opposed to multiples. Anyone know of a Rover shop in North Alabama?

 

There is a good one in bham if that's not too far away from ya. Here is the link to their page. They are a good independent shop n rover enthusiasts too. WELCOME. I would try swapping a plug wire around to make sure it isn't just a bad wire giving you fits or a crappy coil.

 

I replaced the coils and did the whole wire swap thing before replacing them. I took it for a little farther drive and the misfire gets worse the more its driven, but it still stays with cylinder #8.

I'm about ready to throw the towel in one way or another. The LR dealer in Huntsville is the closest to me as transport costs would probably be to much to Birmingham or Atlanta. I'd be sad to part with it, but I've got it get it running.

 

What type of wires and plugs are you using? Have you felt around on the injector wiring harness to make sure the number 8 is seated properly. I only ask from experience. It was a pia since I had lost the metal clip that secures it.

 

You can get a transport pretty cheap to either Birmingham or Atlanta, I just paid $350 to have mine shipped from Atlanta to St. Augustine FL. There's a lot of really good shops in the Atlanta area but I've got a guy in Dawsonville GA that you could call and I'm willing to bet he could help you figure out your issue, the guy is a wiz with D2's. The shop is called RoverLand and the owner's name is Skeeter, call him at (770) 873-2332 and tell himself Deven Rush told you to call him.

 

I have NGK plugs and STI wires. I did ensure the harness was connected to the injector when I checked voltage, but I don't recall messing with the injector itself.

So I got some ice cream and had a chance to think about things. The #8 cylinder is the only one misfiring. And when I spray carb cleaner in that back corner beneath the upper manifold, I hear a slight rise in RPMs. After replacing everything without resolve, it almost has to be a vacuum leak. The only vacuum leak that could affect a single cylinder would have to be the injector wouldn't it? As abran said, its got to be the plenum gasket, the injector o-ring or the valley pan gasket.

So I'm thinking about pulling the upper manifold one more time, really check the orings and seating of the #8 injector, and replace the plenum gasket while I'm at it. Is there any way to test vacuum besides a smoke/carb cleaner test with it running? After that I'm going to have to send it to a shop.