mollydog10 Posted May 16, 2011 Share Posted May 16, 2011 Hi, I have a 2001 4.0 V8 with a Tartarini LPG system and understand that the sparkplugs need regular checking/changing and they have a smaller gap than those running on petrol.(for a stronger spark?) What quality plugs should I use and what is the recommended gap.(I have heared about 0.7mm )? And should I be changing the leads at the same time? I'm new to the P38, V8's, and to the forum, and would like a little reassurance before I start fiddling with it!! Petrol engines always seem far more delicate than a diesel to me!!!! My other car is a Td5 110 G4 LE. Hope to hear from you experts soon Many thanks Mollydog Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted May 16, 2011 Share Posted May 16, 2011 Hi mollydog, welcome to LR4x4. On older range rovers with distributor ignition it's common practice to use smaller spark gaps when running on LPG, but the spark on those is pretty marginal with petrol. Your wasted spark coil packs should give you a much stronger spark and you probably don't need to reduce the spark gap. Use good quality plugs, but you don't need anything fancy - stick to the standard specification for the engine and you'll be fine. Same with leads - only change them if they need it (might be worth it if you don't know the cars history and think they might be on the old side). You can splash out on fancy leads if you want, but avoid 'boy racer' bling which is likely to perform worse than the OEM leads - standard OEM leads will be fine, though, just avoid cheap pattern ones. Oh, and while the RV8 isn't necessarily the most reliable engine in the world it's easy to work on and very forgiving Quote Link to comment Share on other sites More sharing options...
Quagmire Posted May 17, 2011 Share Posted May 17, 2011 ^ What Geoff said, but further to the comment on the leads, use OEM keeping them nicely organised and separated and you'll be fine. Quote Link to comment Share on other sites More sharing options...
mollydog10 Posted May 17, 2011 Author Share Posted May 17, 2011 Thanks guys, I've had the car almost a year now, the leads look good (recent), Dont see a distributor-the leads disappear down the back of the engine. Really must read up on the engine and type of ignition system though!!! The LPG system is sitting on top of the engine so dont want to disturb that at the moment. I did have it serviced by a recognised agent a few months ago- he said fit good quality plugs and reduce the gap to 0.7mm !? Reading an on-line LR manual stated fit Champion RC11PYB4 plugs with 1.0mm gap, also not to adjust gap. I'm just going to change the oil/filter and check what the existing plugs are and what their gaps are at this time (unless I find any problems). One thing I have noticed is a misfire/juddering between 30-40mph when trying to accelerate (without kicking down)? Any thoughts on that? Once again, many thanks I'll let you know how I get on. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted May 17, 2011 Share Posted May 17, 2011 You have electronically controlled coil packs mounted at the back of the engine - no distributor. I'd go with what the experts say about the spark gaps - the authorised agent should know what he's talking about. Not sure about the judder - it could be a misfire, guess it could also be mechanical. Do you get it when running on petrol (if not, that would indicate that it's related to fuelling, maybe an incorrect mixture under those conditions, or spark which is good enough for petrol but not LPG). Quote Link to comment Share on other sites More sharing options...
mollydog10 Posted May 17, 2011 Author Share Posted May 17, 2011 You have electronically controlled coil packs mounted at the back of the engine - no distributor. I'd go with what the experts say about the spark gaps - the authorised agent should know what he's talking about. Not sure about the judder - it could be a misfire, guess it could also be mechanical. Do you get it when running on petrol (if not, that would indicate that it's related to fuelling, maybe an incorrect mixture under those conditions, or spark which is good enough for petrol but not LPG). Dont think it judders on petrol, Its a while since I ran on petrol!!!! Thanks for the info though, I'll see what plugs/gaps are currently fitted and fit the same again. (when the Mrs gets back from work in it!!) Thanks again Quote Link to comment Share on other sites More sharing options...
mollydog10 Posted May 18, 2011 Author Share Posted May 18, 2011 Just fitted NGK R BPR6ES standard plugs as recommended on another forum (cant remember which one now, but poster was happy with them in his 4.0 V8....). Gap is .75mm. Juddering between 30-40mph in top gear now gone!! The plugs I removed were NGK R PFR6N platinum, electrode very small and pointed. Changed the oil too, so now it roars like a tiger and runs smooth as a smooth thing....or maybe its psychological. Now all I have to do is remove the aerial for the remote, so the ECM doesnt stay awake all night and flatten the battery. Youve got to be mad to own any kind of landy. Cheers Quote Link to comment Share on other sites More sharing options...
Escape Posted May 19, 2011 Share Posted May 19, 2011 Just fitted NGK R BPR6ES standard plugs as recommended on another forum (cant remember which one now, but poster was happy with them in his 4.0 V8....). Gap is .75mm. Juddering between 30-40mph in top gear now gone!! The plugs I removed were NGK R PFR6N platinum, electrode very small and pointed. Changed the oil too, so now it roars like a tiger and runs smooth as a smooth thing....or maybe its psychological. Now all I have to do is remove the aerial for the remote, so the ECM doesnt stay awake all night and flatten the battery. Youve got to be mad to own any kind of landy. Cheers The second generation Range Rover (or P38a) has 2 different engine management systems, upto 99 it's GEMS, afterwards Bosch (with a different manifold as well). The BPR6ES is often used in GEMS, I use them as well, regapped to .6 for LPG. The PFR6N with the pointy tip are used in Bosch, because of the shape of the electrode they can't be regapped. Running on LPG you might be better of with the BPR, but for petrol I'd stick with the PFR. Greetz, Filip Quote Link to comment Share on other sites More sharing options...
mollydog10 Posted May 19, 2011 Author Share Posted May 19, 2011 The second generation Range Rover (or P38a) has 2 different engine management systems, upto 99 it's GEMS, afterwards Bosch (with a different manifold as well). The BPR6ES is often used in GEMS, I use them as well, regapped to .6 for LPG. The PFR6N with the pointy tip are used in Bosch, because of the shape of the electrode they can't be regapped. Running on LPG you might be better of with the BPR, but for petrol I'd stick with the PFR. Greetz, Filip Thanks Filip, mines an 01 model (02 registered) so its bosch, I set the gaps to 0.7mm. As I said it runs fine on LPG, I rarely use petrol now. (only a couple of mins for startup). The rough running at 30-40mph in top has gone now too. Thanks for info Mark Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted May 19, 2011 Share Posted May 19, 2011 Juddering between 30-40mph in top gear now gone!! Excellent news - it was a misfire caused by an inadequate spark then (whether due to worn out plugs or just that the type you had in weren't ideal with LPG we can't really say without putting new PFR6Ns in for comparison). Always satisfying when a worrying fault turns out to be dead easy to cure, isn't it? Quote Link to comment Share on other sites More sharing options...
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