Ah right, in that case what the hell is going on?! Haha

Have you checked the general earthing of the engine itself? It's amazing how this can effect the running of the engine.

Hook a jump lead from the engine lift point to the battery negative. If the running improves then that could be an issue.

I've checked and upgraded the earth's from the left and right engine mount, are there any more earthing that?

Could it be to do with the ISV? Is that something that operates better when warm? I'm trying to think of things that wouldn't throw up a fault code

What sort of cold start /choke setup does it have ? Cant help thinking its something to do with that ? maybe ?

What about fuel filter. Do they have a big main one near the fuel tank ?

What about an air leak on the inlet ? A split breather or gasket ?

Coil breaking down ?

Its gotta be something simple now.

Funny that it struggles to start when not parked on the level.

Reading back over your recent posts, it sounds like the TPS might be suspect ?

Edited 16 December, 201510 yr by Polo3

when u unplug the isv with code reader in it does throw up a fualt code so yes it would show up if it was faulty suprising enough though if the injectors are faulty or the wires to the injectors are damaged it still wont throw up a fault code even after we tested them and found they were at fault :/

Polo3: it's GT MPI so it had an autochoke, it had a large filter right by the fuel pump which is brand new (as is the pump) I've had a feel around and can't find any air seeping out but if anyone has a better method of checking for air leaks that would be helpful. Coil shouldn't be breaking down as it's brand new. I think it not starting right when not on the level is just when I have low fuel in the tank and it struggles to reach the pickup. As for the TPS, I thought it was but it hasn't thrown up a code since I cleared them all so I'm not sure anymore

Simon: thank you, I wasn't sure if it would or not. Very odd about the injectors! I haven't tested them but I would assume they're fine as it runs correctly when at temperature but just to be safe, how did you test them?

Thanks for all your replies guys, hopefully we can get to the bottom of this soon!

Edited 16 December, 201510 yr by Bluemarktwo

A good way to test for air leaks round the inlet manifold is to spray brake cleaner round the areas that could be potentially leaking and letting air in, whilst its running.

If it wont idle, you'll need someone to sit in and keep it going while you spray.

I did this with a breadvan that wouldnt tick over when warm. As soon as I sprayed it round the manifold and carb base it smoothed out and idled beautifully, until the solvent evaporated. That turned out to be a perished rubber carb mounting plate. But I had no idea what was going on until that point.

Edited 17 December, 201510 yr by Polo3

That's a genius idea! I'd never have thought of that myself. Would you recommend only using brake cleaner or would anything else work just as well?

I guess anything flammable that can be sprayed around the relevent area. Its just so the mixture doesnt get diluted with air. Probably not a good idea to use petrol :) WD40 might do the trick ? Its flammable but might not be solvent enough ?

I now use meths in a spray bottle as a brake cleaner, but not tried it for finding inlet air leaks. Fortunately, it only happened the once, but I should think the meths spray would do the trick.

Edited 17 December, 201510 yr by Polo3

I went out today and gave every connector a good clean and rinsed out every connector I could find with a crap load of WD40. Seems to be a lot better, I started it and it idles fine for about a minute (whereas it would usually start hunting after about 20 seconds) I'll go out for a proper drive a bit later tonight so see if it's actually cured or just a bit better.

I'm hoping to take it out for a drive tomorrow. I'd do it tonight but the neighbors have already been moaning about the noise all week

Edited 17 December, 201510 yr by Bluemarktwo

Took it out for a proper drive and it is better, still won't idle from cold and still down on power by what feels like a LOT! It's less down on power e.g. it can now pull away properly but still not right. And just remembered the MOT is due on Monday so that will be fun!

Hat a chat to the garage about it when I booked her in for her MOT and they suggested temp sender (done) or ISV. I've got another ISV kicking around so I'll give that a clean out and try it

Turns out it's been running on 3 cylinders this whole bloody time! I think 1 of my spark plugs has just failed because when I pull the HT lead off number 4 it doesn't make a different but I have spark from the lead

How did u test the lead without the spark plug in?

Glad it's all sorted for you mate

Love a simple fix! Hopefully once she is running on all 4 you'll be able to enjoy driving again :)

I just took the lead off the plug and heard it arc to the block (and felt it arc through my thumb)

Yeah hopefully this will finally fix it! Lord knows it's been a long road to recover for the poor girl! I ruined spark plug would certainly explain it being down on power and averaging about 14MPG! Unfortunately I won't be with her over Christmas so I'll have to fix her up in January and book a retest!

Right so I got back today and changed out the spark plug for a nice fresh one..... It made no difference whatsoever so it's still running on 3 cylinders. I'm guessing this has to mean there's no compression in that cylinder? Can't think of anything else it would be...

The old plug came out black

Edited 3 January, 201610 yr by Bluemarktwo

I've got a spare set of leads so that will be my next check and pray it I'd just a bad lead. I did hear the spark from the lead but it may just be too weak to properly ignite the fuel in the cylinder. When the spark jumped through my thumb it didn't feel like a significant shock. The inside of the lead cap is matte and looks to have some limescale type deposits in it

Can you swap the lead for another one and see if the missfire moves with the lead?

Yeah I'll be able to do that. Would it be better to do it that way or just swap the lead for one from a spare set?

I'd just swap 2 leads about just now. If the miss-fire moves then you've found your issue. Then try a spare if you have any handy.

Right, I think I've got it running on 4 again now. Swapped the leads and the misfire moved. Put a full set of new leads on and it runs well...... For about a minute or so.

It then starts to hunt as the idle keeps dropping, it will do this for a few minutes before eventually cutting out. When running, unplugging the blue temp sender does smooth it out so it sounds like the ECU is happy again, no codes thrown up other than stuff I unplugged. So still no idea whats causing the idle hunt/drop/cutout issue. Didn't get hot enough to see if it cleared up in the same way

I also tried spraying a little bit of easy start around in inlet manifold/Throttle body etc to check for any leaks and that didn't seem to do anything

Rocker cover gasket is in pretty poor shape, could this have anything to do with it? I wouldn't have thought so but once again clutching at straws

Edited 4 January, 201610 yr by Bluemarktwo

The next time it starts to hunt unplug the lambda and see if that smoothed it out?