I'm going to have my little misfire sorted. When Simon did the LPG he reckoned there could be a dodgy injector.

i thought i'd have New coil packs, New HT leads (8mm), New spark plugs.

And it seems a bit of a waste to go in for just injectors so what's your thoughts for replacing parts while its all in bits???

I'd appreciate a shopping list of gaskets and such that would be worth doing. I figure to just have everything done at once whether it needs it or not rather than having to strip it back down at a later date costing twice the cash.

Rockers, upper inlet manifold, valley gasket etc.

thanks very much

I wouldn't go as far as the valley gasket unless there's a reason to suspect it needs it. You'll need an upper manifold gasket as that will have to come off anyway. Rocker cover gaskets would be a good idea while in there and you'll also need injector O rings too.

Thanks. I don't suspect anything wrong with the valley gasket. Just thought while it's all out, would make sense to go the extra mile and do it. If you reckon leave it, then I will.

I don't like the look of the price of new bosch injectors. Can I send mine away to be tested? By all accounts, there should be 1 iffy one.

Unless you're removing lower inlet manifold, you don't need valley gasket. Just get complete injector O ring set and remove injectors in situ.
Why not just get the existing injectors cleaned and tested rather than just replacing them?
EDIT- blimey, 2 more posts while I was typing this :)

This is the right gasket isn't it?

http://www.paddockspares.com/err6621-gasket-inl-manifold.html?gclid=CNDUxOytvtQCFdeRGwodckELVA

The one that's in.2 parts is for the gems engine?

That's the one. It's only a bit of stamped tin though. I've reused the same one quite a few times with a quick spray of blue Hylomar for luck.
BTW The MrInjector that I linked to above did a good job a while back cleaning and testing a set of TR6 injectors for me.

Orangebean wrote:

That's the one. It's only a bit of stamped tin though. I've reused the same one quite a few times with a quick spray of blue Hylomar for luck.
BTW The MrInjector that I linked to above did a good job a while back cleaning and testing a set of TR6 injectors for me.

Thanks for all of that. Are the injectors a quick turn around?

Few days I think, but I didn't need a rush job.
You could just get Blue Peterish with a battery, large can of carb cleaning spray, some fuel hose and a clear jar and clean and test your own injectors, then when you know how many duff injectors you have, buy some of these:
http://www.ebay.co.uk/itm/Range-Rover-P38-Discovery-2-Petrol-V8-Bosch-Fuel-Injector-ERR6600-Warranty-/331309241612?
With a warranty, once you've run them through your cleaning/ test rig and either sent them back or they're good to go, at that price it's a job well done.
After all, your car is going to primarily run on LPG so the less you have to spend on the petrol side, the better!

Orangebean wrote:

After all, your car is going to primarily run on LPG so the less you have to spend on the petrol side, the better!

With that last statement, i think you've just made perfect sense!

Why am i bothering to chase one potentially dodgy petrol injector when i believe that the car consistantly underperforms on both petrol and gas??? (i've winged about this on my other posts) The petrol injector has nothing to do with the gas does it?? Would it not be more likely that something that both systems have in common is to blame? i.e HT leads, coils or spark plugs???

Sure, i'd like to fix the petrol injector, but it's not particularly noticeable and as you can probably tell, i know next to nowt about cars. So if it hadn't been pointed out to me i wouldn't have known.

Is it worth the hassle and cost messing about with the injectors that won't get used??

But the gas system is slaved off the petrol system so if there is a problem that is causing it to run badly on petrol, that will be reflected on gas. But I would agree that leads, plugs and coils could equally be the problem.

Sorry. I'm not really sure how it works. Only what i've seen, read or surmised.

If gas doesn't run through the petrol injector, how does a petrol injector affect the gas system?

Simplifying a little, but briefly, the LPG ECU takes the injector timing of the petrol injectors and adds a bit to that timing to suit LPG burning characteristics then triggers the gas injectors. When running on LPG the actual power to the petrol injectors is cut off so they don't open. In effect this means that the LPG is using the petrol fuel injector timing as determined by the cars engine management system. So, if the cars petrol engine management system is doing odd things to compensate for poor running, that will be reflected in the LPG system slavishly emulating the petrol system.

Now i understand. So best to sort the injectors then!

Thanks very much.

Another way a faulty petrol injector would mess things up would be if it wasn't shutting off completely. In the scenario above where the car is running on LPG, the power to open (and close) the petrol injectors is shut off, but the injector is still pressurised with petrol, and if it's leaking petrol, not only will that cylinder get it's desired shot of LPG, it'll also get the leaked petrol added to it at the same time, causing it to run rich.
That same leaky injector would also mess up things running on petrol.

okie dokie. i've watched a few youtube vids of injector cleaning Heath Robinson style. might give that a go first to see where we're at before sending them away. If they're all good bar 1, i'll just replace 1.

I managed to buy new replacement (upgraded) injectors for my GEMS engine for less than the cost of cleaning the crappy old ones.

The new ones were from a 1.4L K series engine, and were recommended as a direct replacement for the original lucas items. I have the part number somewhere.

Found a couple companies on ebay selling them from new crate engines. I presume they're buying them and then modifying the engines for kitcars or whatever and the injectors are surplus.

I suspect yours is Thor so they'll be different to mine though.

yep. Thor. Cheapest new ones i've seen are £45 a throw.

which spark plugs d'ya recommend? £10 a go is not an option by the way. lol

I've read NGK BPR6ES will do. If I stick my reg number in a few websites, they recommend either a BERU or Bosch. £2.50ish each gapped at 0.8 which is correct I think.

Also, should I gap them to 0.7 because of lpg or just leave them standard?

Cheers.

NGK are the ones to go for
PFR6N-11 are guaranteed to fit all Thor motors. The last heads had a smaller machined socket.
NGK BPR6ES fit most peoples Thor motors though.
I leave gap as standard
Cheapest around seem to be:
PFR6N-11 http://www.ebay.co.uk/itm/Rover-25-45-75-218-418-NGK-Platinum-Spark-Plugs-Set-x-4-/250633164017? (2 sets of course)
BPR6ES http://www.ebay.co.uk/itm/FOUR-x4-GENUINE-NGK-SPARK-PLUGS-NGK7822-BPR6ES-/321936375235? (2 sets)

Ta.

I was also thinking of cleaning up the rocker covers. Is it worth the effort of polishing or just spray em up?