The Rover-Landers of BC

EDIT Decided to rename the thread (not sure if it worked) so it would be easier for others to search it and find the solution./EDIT

So here's an interesting one... The way my Rover is running, it idles funny (RPM stays consistent but the truck shakes and sputters) and not always at the same RPM... and it seems to have two modes while it's driving. It has one "normal" mode where it runs and drives perfectly fine and then it has a "bad" mode where it misses and backfires like mad and will barely even move forward under its own power. When it's in "bad mode" I can sort of half-solve it by letting off the throttle and then getting back on it.. That seems to clear it up and it will run normal for a few seconds (about 5 seconds or so) then start stumbling again at which time I let off the throttle again and then get back on it. Sometimes I'll have to do this on-off business for quite a distance and it makes it really difficult to maintain highway speed. I also don't imagine it's very good for the poor thing.

What's worse is it seems to switch between these "modes" whenever it pleases and it even idles much better when it's in "good" mode. I don't think it's any major mechanical component because if it was, it wouldn't have a "good" mode. It feels like an ignition problem.

I haven't had any luck with this one and of course I've changed all the obvious things. New plugs, wires and new coil. I haven't changed the cap or rotor but I opened it up to take a look and everything appeared to be in order. To be honest I don't really know what I'm looking for but it all seemed normal? Didn't look worn out. It does also have an exhaust leak in front of the O2 sensors somewhere which I've temporarily plugged up with orange high heat RTV. I doubt that would cause this issue though.

A friend of mine at work said to check the EGR valve as it may be sticking open/closed whenever it pleases and causing these sorts of troubles. But... it doesn't seem like it HAS an EGR valve. I don't remember coming across it when I did the head gasket change and both Lordco and JB parts said they have no information about an EGR for this truck. I also didn't see it on Rovers North.

So... My question is, do these engines even HAVE EGR valves? And if so can I either a) replace it for cheap or b) bypass the stupid thing? Also, has anyone else ever had this problem or even heard of something like this happening? It sure seems crazy. The check engine light isn't coming on so I don't think it will have any codes?

Not sure what vehicle you are talking about, but I have not seen an EGR valve on Disco 2 and earlier.

Have you checked on ECU codes? Have you done any ECU troubleshooting? I would go through the whole ECU troubleshooting guide in the workshop manual. This basically checks that all the sensors are reporting correct values back to the ECU. If it is not there, it could be an intermittent ignition problem.

I'm presuming you are referring to your RRC in your picture....
My RRC had similar symptoms when the air cond kicked in, it would pull down the rpm. Make sure it is all turned off and see if you still get the same thing.
Another possibility is the Stepper Motor which can play around with your rpm, normally just needs cleaning.

If you haven't found it yet this is a great resource for Range Rovers...
http://www.rangerovers.net/rremedies.html

Cheers,
Andy

I had found that before, yes. Thanks Andy.

I know for sure it's not the air conditioner because I took the belt off it and put it on the other side (needed a belt) and since I never really used the A/C anyway I've just sort of been too lazy to put a belt back on it.

I almost think it might be a bad rotor inside the dizzy but I don't like the idea of throwing parts at it. Any way I can know it's the rotor with a little more certainty? I'm also unsure if my dizzy is a stock/OEM type Land Rover unit. The previous owner swapped some parts on this thing and the distributor doesn't really look stock. I guess I'm going to have to take a good look at it and see if I can find a part number on it and go from there.

This one is a real head scratcher. I drove the truck to work today and from my place to the lake (where we do our morning military runs) it ran like crap. When it runs crappy not only does it sputter, miss and backfire it also smells strongly of fuel from the exhaust (to be fair, it has no cats). After the run, it ran perfectly from the lake to Subway where I had breakfast. No sputtering or missing, no backfiring, no smell and better idle. Then I drove it from Subway to the gas station and it seemed fine. After putting gas in it and starting again, it ran poorly halfway to work and then seemed to run fine for a while.

Now I'm at work and I'm just... totally confused about what it could be. I'm leaning toward it being an intermittent ignition problem but the cause of it, I have no idea. It probably isn't plugs/wires/coil because those are all new. The dizzy cap looks good so I don't think it's that but maybe it's the rotor? I just don't know at this point.

I'd put my money on a bad stepper motor. Try cleaning it with WD40, or carb cleaner. If that doesn't work, get one for a Chevy Astro van.

e.prevost94 wrote:I'd put my money on a bad stepper motor. Try cleaning it with WD40, or carb cleaner. If that doesn't work, get one for a Chevy Astro van.

I had previously cleaned (and then) replaced it with one that I bought of eBay but I don't know if I got a good one or not. Might be a crap one. This was back like when I first bought the thing, one day the stepper decided I was going to idle at 2000 rpm. Lordco had them but they were like 120 bucks. Might be worth asking JB auto. Ended up first borrowing one off my friend's Chevy truck.

I'm thinking it may also be the throttle position sensor.

So anyway last week I replaced the rotor and the dizzy cap. Cost me 30 bucks and they're normal tune-up items anyway so it's not a waste of money. So now it has new plugs, wires, cap and rotor. Some of my issues went away. The misfiring seems to have stopped but it still idles wicked rough and can't find idle when you first start it up (revs up and down on its own, feels like it might stall) but after a while it figures itself out. But then it still idles and shakes rough. And it still backfires like a SOB but at least it can now move under its own power I don't have to go on-off the throttle to maintain speed. Thought perhaps my exhaust leak might be causing that so I picked up some of that fiberglass exhaust wrap and wrapped up the area below the manifolds all the way down a bit past the O2 sensors. Now the exhaust isn't leaking into the engine bay and the cabin area so I've fixed the problem of myself inhaling fumes and that should reduce under-hood temps a bit but it still backfires a lot and has a rough idle. I'll clean up the stepper motor again and see if that does anything but do you guys know the symptoms of a faulty throttle position sensor? I thought I had a TPS problem before because my truck had some shuddering problems on the highway (felt like it was going on-off on its own) and I had removed the sensor and tried to test it with a multimeter, only to conclude that I couldn't tell if it was faulty or not. Put it back in and eventually the highway issue solved itself.

So yeah..

I guess it's not the EGR valve as the truck doesn't appear to even have one. So it may be the stepper motor and it may be the throttle position sensor. It's all a mystery but I must admit I'm having a lot of fun faultfinding and I'm learning a lot about vehicle maintenance. That's actually the reason I bought this truck, I figured things would go wrong with it and I could force myself to get my hands dirty.

Thanks for the advice so far, everyone. I'm going to check my stepper motor and blast it out with some WD40 and I'm going to look into getting another TPS if they're not too expensive, assuming that could cause my enrichment issues and backfiring/bad idle. I'm thinking it may have an intermittent "open" in the TPS circuit providing max voltage to the ECU and telling it to piss fuel into the cylinders like mad. That could very easily cause my rough idle and my backfiring, no?

Have you gone through and tested all of the EFI items? It takes an hour or two and you can stop guessing what might or might not be wrong.

It is also "fairly" easy to hook up a computer and monitor most of the items directly. If you are not aware of that option and are interested, I could dig up the links to the hardware and software information.

red90 wrote:It is also "fairly" easy to hook up a computer and monitor most of the items directly. If you are not aware of that option and are interested, I could dig up the links to the hardware and software information.

You can just hook up a laptop and monitor it directly? I do like the sounds of that as I'm more technologically inclined than mechanically. Comes with my youth, perhaps. I've got a good set of soldering and wire/connector repair tools here at work (avionics lab) if/when I have to make any sorts of adapter cables.

Sounds like fun. If it's not too much trouble I'd be interested in the links. I don't want to trouble you too much, though.

Rovergauge.

https://code.google.com/p/rovergauge/

Assuming you are fairly technically literate, it should be pretty simple. The only thing you need to buy is the USB/serial cable with an FTDI chip in order to setup the non-standard serial protocol. It is all explained in the link above.

My truck did the same thing just before it blew up the ignition module, then would die completely. Not sure if that is your issue but worth a look. Went to MSD dizzy and never looked back - till I went to diesel!

Thanks for the advice, all.

I'll take a look into that rovergauge program. The techie side of me gets excited at the thought of plugging a laptop into my 20+ year old truck. I wonder what I'll see. Hopefully my poor old green brick doesn't blow up the ignition module but I suppose that's a possibility. It could very well be fried, who knows. Only testing will reveal. I'm not opposed to replacing the distributor but.. I mean.. it's such a pain in the butt. You're like halfway or more into a head gasket job/top end rebuild at that point, aren't you? I just did that a few months ago. Dang it.

Will do more testing.

Thanks for answering my questions. I tend to have a lot of them. Inquisitive mind, first crack at hands-on vehicle maintenance, etc.

Removing the distributor is easy. Remove the 9/16th nut holding down the clamp, pop off the distributor cap, undo the connector going to the ignition module, and remove the assembly. Even the most simple minded of us shouldn't take more than 10 minutes to remove it. :lol:

Oh yeah, and mark where the distributor is pointing to get you in the ball park when you put everything back together. Unless you don't value your sanity...

Oh, you mean you can replace the distributor without yanking off all the intake parts and fuel rail and everything for access? If it's as easy as you make it sound, I'm not too worried. If I discover the problem to be in the distributor I'll just swap it out for something a little more meaty like the MSD unit. I changed my coil for an MSD blaster2 performance coil about a month ago and that seemed to improve things. Things improved slightly with all the ignition parts replacements I did.. but then again, most of those are "tune up" items anyway.

If you are looking into a Mallory Dizzy, make sure you get the tall one rather than the short one. The tall one will clear the upper rad hose. I recall I got mine through lordco for under $350 but it did take a bit as it came from Mallory in cali.
Pat

punkinracer wrote:If you are looking into a Mallory Dizzy, make sure you get the tall one rather than the short one. The tall one will clear the upper rad hose. I recall I got mine through lordco for under $350 but it did take a bit as it came from Mallory in cali.
Pat

Thanks for the heads up. It may end up being that my ignition amplifier is hooped and that will require a new dizzy most likely.

Anyhow here's an update. I gained access to the code reader under the seat and didn't find any codes showing. Thought it might be broken so I unplugged my ECU for a bit and plugged it back in. That threw code 02 like it's supposed to so I cleared it. I started it up and it ran the same as before. Idled it for a few minutes. Didn't see any codes come up and the check engine light didn't come on (It never does anyway, I actually think previous owner disabled it somehow.. what kind of idiot does that?) so I turned it off. I had/have a sneaking suspicion about the throttle position sensor so I just unplugged it and ran the truck without it plugged in. Took it for a drive and it runs/drives exactly the same as before I unplugged it. So I'm thinking that sensor is toast, even though I previously metered it for resistance and found it went through the motions best I could figure. I'll have to do it again now and see if it's changed. Got home and still no check engine light but it was throwing codes now. I have to cycle through them but the first one it showed was 44, for left O2 sensor. I'm going to cycle through them when I have more time and write them all down. I suspect it will throw both O2 codes as well as some misfire ones and who knows what else.. but then I'll go through and check the components that it points me toward. Looks like a lot of checks want me to meter sensors and things while they're still plugged in. I'm going to have to splice some multimeter test points into the wires I guess, that'll save me time in the future.

Strange Rover wrote:

punkinracer wrote:If you are looking into a Mallory Dizzy, make sure you get the tall one rather than the short one. The tall one will clear the upper rad hose. I recall I got mine through lordco for under $350 but it did take a bit as it came from Mallory in cali.
Pat

Thanks for the heads up. It may end up being that my ignition amplifier is hooped and that will require a new dizzy most likely.

If its the ignition module, which by the codes it's throwing sounds like the issue, why would you replace the entire distributor? You know you can replace the module separately, right? :roll: http://www.roverparts.com/Parts/STC1184.cfm

e.prevost94 wrote:

Strange Rover wrote:
Thanks for the heads up. It may end up being that my ignition amplifier is hooped and that will require a new dizzy most likely.

If its the ignition module, which by the codes it's throwing sounds like the issue, why would you replace the entire distributor? You know you can replace the module separately, right? :roll: http://www.roverparts.com/Parts/STC1184.cfm

Thank you, I guess I assumed it might have been integrated. I suppose the word "module" should have tipped me off that it was not. My mistake.

It certainly seems like my problem is ignition related and most of the components are new except that one and the dizzy itself. I was also thinking it could be a problem with the air gap but.. I'm going to try and test the ignition module first as I'd be leaning more toward that than the gap. Also going to test the throttle pot because the truck runs the same with it plugged in as it does when I unplugged it. To me that indicates a bad sensor but I guess I could be wrong.

I'll do some more testing when I get home after work. Girlfriend will be at work so I should have some time to myself.

I certainly hopped into the deep end of the pool with this Land Rover, having never really spun wrenches on a car before. I thought to myself, I fix aircraft electronics how hard can cars be? Kinda hard, as it turns out. I sure am learning a lot, though.

You can certainly just replace the module, but personally after replacing 3 in 2 years I changed over to the Mallory and never had a problem again. The nice part about the Mallory is should you need any parts for it Lordco always has them in stock.

If you do just replace the Rover module, there was a recall sometime in the early 90's that changed the mounting from the distributor to the fender well near the coil. The module is the same one but I guess the theory was that the dizzy mount got the module too hot, so it was moved. Just make sure the ground is super clean and it is heatsunk well.

Pat

Another update on this for curious parties, since I had some time to dig into it some more...

I checked my air gap and it was way too big... so I got out the brass feeler gauges (can't use ferrous ones apparently) and I fiddled it down into the proper range. Ran the truck for a bit, no noticeable difference. So I acquired a new ignition amplifier module but it came in a bag that essentially said "once you open this we won't take it back" which made me really not want to waste my hundred dollars... so I got out the multimeter and started chasing sparks and I couldn't find any glaring faults in the ignition system.

So I went to the code reader and figured out how to cycle through the codes (that plug that you have to unplug for 5 seconds was difficult to find) and it was throwing the code for BOTH O2 sensors (but still no check engine light? Does the damn thing even work? I know the bulb is good). Seemed unrealistic so I followed the book checks to see what was going on and found the heater coil in the left hand O2 sensor was goosed. I replaced it with a spare I had kicking around and now the truck isn't throwing codes any more but it's still running rich as all hell. I mean, it's driving kinda normal but it's idling rough and sputtering/backfiring because of all the damn fuel being put in. I run a pretty open exhaust so it's easy for it to backfire.

I checked the throttle pot and the resistance wasn't 5k ohms like it should be however it IS providing the correct voltage to the ECU. So I don't think that's the issue.

But now that all my ignition problems are solved and it's no longer misfiring, just running wicked rich, I'm going to take a look at the coolant temperature sensor to see if that's my culprit. It seems the most likely candidate at this point... it's running so rich the fumes make my eyes water. Good thing I don't have any cats or they would almost certainly be fouled by all this fuel.

So yeah I'll check the coolant temp sensor next and we'll see what we see. I think I'm getting close to having this poor old thing running right again.

BUY A DIESEL AND SAVE YOURSELF THE HEADACHE :mrgreen:

franko wrote:BUY A DIESEL AND SAVE YOURSELF THE HEADACHE :mrgreen:

Too much of a headache to acquire and figure out how to install in my driveway :lol:

So after driving it some to get it all warmed up, I came home to do the checks and when I went down to the ECU to access the pins and start testing I found the code reader was once again showing the codes 44 and 45 for both O2 sensors but it was also showing code 14 (coolant temp sensor) so I got all excited and did the test only to find out it tested perfectly fine. Damn it, that's not the result I wanted!

I suppose it may only work intermittently (which would explain why the truck works great sometimes and horrible others) or worse, I may have a problem with the wiring itself... I really hate wiring... a new sensor is only 30 bucks and I can have one tomorrow so I'll probably just do that. If that doesn't fix it I'm going to have to wring out the wires and I really don't want to :(

I have a spare efi harness if you need it. A lot of that wiring goes away when you run a diesel - only 3 wires run the whole motor!
Pat

Just an update on this since I haven't said anything in a while.. It's fixed (for the most part).

I finally ponied up and replaced both the oxygen sensors and now it runs/drives just fine. Still has a lumpy, kinda sloppy idle but it doesn't hunt around or idle really low and nearly die any more. Doesn't hesitate when you accelerate from a stop. No more insane backfiring. Can move properly under its own power and I don't even need to floor it everywhere... Basically a complete fix! Go figure it would be those stupid things, after all the time I spent trying not to have to replace them.

After the swap I kinda just eyeballed (earballed?) the idle screw adjustment until it sounded happy-ish and the revs were about right and then I took it for a drive. Drove it to the base gym and back without a hitch.

Still throws code 45 for the right hand O2 sensor even though it's new. I'm thinking there's an air leak or dirty injector on that side causing the code and the bumpy idle.. and it's throwing code 48 for the idle adjustment too. That's my fault I obviously didn't get it quite right. Will do the proper procedure soonest so it's actually set right. Will clean the idle air controller again and the throttle plate, too. Maybe run some injector cleaner through it as well.

So yeah. It's back to driving normally the way it used to with only the bumpy idle that it's had since Feb-ish. There's an audible chattering sound on the right hand side that I think may be lifter tick (though it may just as easily be an air leak and be causing that code).

She's a work in progress but at least it's back to reasonable function so I can drive it. Happy day! I missed my Rover :bounce: