I've been patiently chasing a phantom vacuum leak for weeks using every trick in the book short of an actual leak down test which I'm leaning towards. When I install a vacuum gauge it does have a strong steady signal but I cannot recall the value off hand. I recently installed head gaskets and at that time, I scrubbed and cleaned every part, in and out and took my time to be sure all mating/sealing surfaces were immaculate and properly assembled. (I spent most of my career working with UHV vacuum chambers and have a critical eye toward seal integrity, not to mention I've built about 20 different motors over the years with great success). This rig ran great for several months up to the point I did a good 400 mi trip which inluded about 150 mi off road and a solid 20mi of silty dusty nastyness..All hoses are new or carefully inspected for dry rot/ cracking. I pulled the flame trap and unrolled the steel mesh, cleaned it, rolled it back up and reinstalled it, also made sure the PVC T was clear as well as the little inlet on the driver side rear valve cover (poked a poker through it even). I have sprayed ether and carb cleaner all over the motor and any ancillary vacuum lines and components, also have
pinched/ capped/ plugged every line in my troubleshooting. Everything I've done tells me no vacuum leak, but my gut says I just can't find it...

The mill does eventually stabilize after about 3-4 minutes, and when it does, it is so smooth running at around 750 rpm that you can't feel it running. They must have balanced these motors pretty well.

It acts as though the ecu can't settle out in a timely manner.

I'm considering dropping a few bills into new o2 sensors and a new coil for piece of mind anyway, maybe one of them will be the culprit, mybe not. Truck has 130k, is a 92 model, parts are originals, can't hurt to refresh them anyway. The old ones I can keep on board for spares in case none of the parts improve the idle.

 

Perhaps attach old school vac gauge to aid the search. And clean IACV again, plus bore it goes into. It is a computer controlled vac leak....

And there is the connection between lower manifold and upper, which has no gasket on mine, just a little trace of something that looked kinda like varnish.

 

I went back and hit it again at idle with a can of carb cleaner, I sprayed the whole thing at every seam of the inlet sode of the motor......I dont detect any leaks..pulled the MAF connector, it died instantly..put MAF connector back, restarted. still hunting, pulled the connector of the IAC, no change at all (same as before, this I have tried..) still hunts, that whole assembly is immaculate, and the stepper is a new one as well. Occasionally I hear arcing, but have yet to see it..I need to spend a few hours letting at idle with the light out and see WTF that is..sounds like it's on the drivers side, like the coil wire or one of the left bank wires is arcing through..this is going to cost me as much beer as land rover parts..al the ignition parts are new (cap/rotor/wires), but not premium, justs the econo stuff...highly suspect.

I may pull the cap and rotor and clear coat them with laquer, works good on the dizzy of the old Cessna 195 (pretty much a mandatory fix to keep the cap from tracking..) Then I can put a set of kingsborn wires on it to be certain thet are rock solid.

after 5 minutes of running from dead cold (which is about 100deg ambient here in az right now), the coil was so hot after 5 min of running, that it was hotter to the touch than the coolant hoses. I think that is wrong. Pretty sure the coil over there on the fender should not get that hot...

 

Agree on the hot coil issue. Agree on watch for arcs in black of night. RAVE says normal for MAF to behave that way (if unplugged at cranking it may start, reach 500 rpm, then die). My PCV system had what looked like vaseline plugged up in the passage between hose entry on the throttle body and the "floor" of the butterfly valve area. If the PCV system has problems, it could look like un-metered air (vac leak) and the ECU is trying to compensate. Truck warms up and something seals up, and it goes away?

 

Well, I went ahead and ordered a coil. I'll see what that does.

In the mean time, I am going to circle back and double check my distributor to be sure something isnt loose or floating around at the pickup coil.

I noticed my vacuum advance seems pretty ineffective, its not leaking, but it acts like the diaphragm is locked up. I can draw a vacuum on it manually and not get it to pull in any advance at all. this could be the culpprit, maybe the pickup plate is just flopping around in there causing all the instability. I guess I overlooked it since It was all pretty much fresh just prior to my 400mi trip. maybe shook something loose in there is all..

It's got to be something stupid is my guess..I think my motor is in tip top shape in general. I just need to be humbled by it before I can become its master!



I have a Link ECU sitting in my gunsafe, if this thing really gets quirky, no more mister nice guy! Then I'll be all set for the SBC/700R4 swap when I'm done with all this cute little rover V8 guff...(just idle threats! I dont think I would actually defile this RRC, it's a nice one!)


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I really got off topic/relevance in this forum...

back to origanl topic, yeah, I like the landrovers fro thier ruggedness and off-road capability. I laugh at the 24in wheel ghetto cruising range rovers...I hate to be associated with that crowd, such a waste.

That and the whole yuppy elite land rover thing cracks me up.

Pretty sure my old RRC has enough AZ pinstripes and dirt and dents on it to ward off the white collar clowns, they see me as about as redneck as it gets...driving some old jalopy range rover jut because I cant afforsd a new one type thing!

fact is I woulnd own anything newer than maybe an LR3, but man they look vastly more complex than anything prior..

for me, I'll seek out older and older ones, I see a lot of decent but neglected RRCs around my neck of the woods...people with no haps cannot afford to resurect them, so they end up being really cheap (but needing a lot of work...)

I'm still on the uphill side of the learning curve, but I find these rigs to be substantially better overall than any other 4x4 I've had for out and out offroad use. They are comfortable, wheel great, and super rugged/strong. I've had multiple jeeps, landcruisers (FJ40), Broncos, blazers (Blazer is actually a tough act to follow)..and a variety of trucks..The Rovers are by far the most plush and easy to drive in extreme conditions...but they are needy...works for me though, I like staying up with my vehicles and keeping them up to par. This RRC is challenging me a bit, and I like that to a degree. I do trust it to push on...even if it has some quirks..

 

I joined this forum yesterday looking for some peace of mind and some affirmation that I am making a good decision. This particular thread has helped me realize what I have known for a long time. I have seen my feelings reflected in so many of these posts ($500 truck club, hoping to get home in the same car, snobby dealership people, etc.). We do not wrench on our rig; we have always maintained it at the dealership. I recently added up my costs, and since 2007 have put a ton of money into it ($9,700) for the 22,000 miles put on it in that timeframe. Some years have literally cost me dollars per mile driven. While we LOVE our 2002 Disco Kalahari edition (Borrego Yellow) and it is in excellent shape, it is just costing us too much to maintain. It is no longer a DD, and has low mileage (just over 72K). I am torn. Do I sell to CarMax, where it will just get auctioned off? That is hard...we have such an emotional attachment we want it to go to a good home...we want someone to love it and take care of it. KBB says it's worth about $6,300 for trade in, $8,400 for private party and $10,300 for retail. It does not, however, have a provision for the fact that it has so many extra things on it as a Special Edition vehicle. After spending hours on this forum yesterday I think these prices are a pipe dream. I was hoping to find an enthusiast to sell it to, as I don't want the uninformed saddled with the expense, only to come back to me angry. We are the original owners, and it has been our favorite vehicle we've ever owned, while simultaneously being the bane of our existence. It's wonderful off road, and when we get out there we are in heaven while also terrified of the expense of potentially needing a tow out of the sticks. We will be sad to see it go, but the time has come to simplify our lives. Any thoughts on this would be greatly appreciated, as I am very torn about the correct course of action. I know the correct thing to do is to take emotion out of it, but that's easier said than done when such a distinctive and beautiful vehicle are involved.

 

In the same boat. We love our 2010 LR4 but,,,WAy too many trips to the service department for only 32000 miles, have replaced the brakes, tires, fuel injectors, unresolved check engine light, unable to start periodically, brake squeal.
I am certain LR reads these posts - hey Tata you have a product that people really want to love but can't !! Get your act together.
The warranty on ours is about 4 months down the line which by no small coincidence will be when I get rid of this beast.

 

Those LR4's are vastly complex...You might as well drive a space shuttle.

 

Motivated by profits. Make money on initial sale, finance of the vehicle, all the dealer service calls, parts, and now the technology that ties the owner to a dealer for service for the life of the vehicle.