Car stuttering now more info
Discussion
So following on from the last thread,
Car was stuttering or almost cutting out under boost, now the good new or maybe bad is that it's getting worse.
I changed the plugs for ngk's and gapped them at 30 thou, no difference but maybe a little worse, indicative of the gradual fail.
Then checked out the wiring to the pump where I discovered its already been done. It did show some corrosion so i stripped and replaced where necessary. Also cleaned all relay contacts and earth points. At this point I realised it's already had a 044 pump fitted. I had a brand new m400 one sitting so fitted that to test. Same problem.
Now though, things are getting worse, it doesn't just cut out but I can also get big backfires. I watched the boost and it seems to be rising to around 0.8 before it cuts out, is this the problem? Ie the ecu cannot stop the boost increase so cuts it?
Either way looks like I need a specialist, just a nightmare being so far up Scotland!
Car was stuttering or almost cutting out under boost, now the good new or maybe bad is that it's getting worse.
I changed the plugs for ngk's and gapped them at 30 thou, no difference but maybe a little worse, indicative of the gradual fail.
Then checked out the wiring to the pump where I discovered its already been done. It did show some corrosion so i stripped and replaced where necessary. Also cleaned all relay contacts and earth points. At this point I realised it's already had a 044 pump fitted. I had a brand new m400 one sitting so fitted that to test. Same problem.
Now though, things are getting worse, it doesn't just cut out but I can also get big backfires. I watched the boost and it seems to be rising to around 0.8 before it cuts out, is this the problem? Ie the ecu cannot stop the boost increase so cuts it?
Either way looks like I need a specialist, just a nightmare being so far up Scotland!
Hey Tux, didnt know there was a separate controller, my first turbo car so very much a noob, im used to throttle bodies! I just thought the ecu set up the boost?
Slipstream, Im fairly confident it would do it from straight out cold but have not given it full throttle until at least 3 miles down the road at which point it does it. On a run last week it was doing it very badly but still only on full throttle then I stopped to collect some things where the engine was left idling for around 2 minutes so getting hot but when settong off again it was actually a little better so I dont believe its heat related.
Thanks guys off to learn about the boost controller.
Craig.
Slipstream, Im fairly confident it would do it from straight out cold but have not given it full throttle until at least 3 miles down the road at which point it does it. On a run last week it was doing it very badly but still only on full throttle then I stopped to collect some things where the engine was left idling for around 2 minutes so getting hot but when settong off again it was actually a little better so I dont believe its heat related.
Thanks guys off to learn about the boost controller.
Craig.
Hi Craig,
Another North East owner here.
I've had similar problems. One time it was the fuel pump (low pressure) and the second time was a blocked injector. How did the plugs look when you changed them? Were any of them black? Check the filter as well. It may be full of debris.
Does it run fairly smooth on low engine loads and then start miss firing when you put your foot down?
Cheers,
Graeme
Another North East owner here.
I've had similar problems. One time it was the fuel pump (low pressure) and the second time was a blocked injector. How did the plugs look when you changed them? Were any of them black? Check the filter as well. It may be full of debris.
Does it run fairly smooth on low engine loads and then start miss firing when you put your foot down?
Cheers,
Graeme
Hi Graeme, Where are you based?
Little more info today and its sorta good news. Decided to disconnect the boost controller on the way to work and for the first 5 miles the car was great. In the wet with it disconnect she is so docile so that will def be a mod!
However the problem soon settled in and gradually got worse to the extent I nearly didnt make it in! After 30 miles she started cutting out even on very light loads and absolutely no boost. Then when going through a small town I got complete cutout but as it happened I noticed the fuel pump die at the same time. Strangely I removed an 044 and fitted a M400 pump which is actually noisier so Im able to hear it when doddling around in town. So I know its either ECU power or fuel pump power. As I did the fuel pump mod at the weekend I will short out the relay and permanently feed the fuel pump and see how I get on. My laptop was flat this morning but will also connect the laptop to see if the ecu was switching the pump off/killing the original relay or if I lose connection with comms.
Wish me luck!!!
Little more info today and its sorta good news. Decided to disconnect the boost controller on the way to work and for the first 5 miles the car was great. In the wet with it disconnect she is so docile so that will def be a mod!
However the problem soon settled in and gradually got worse to the extent I nearly didnt make it in! After 30 miles she started cutting out even on very light loads and absolutely no boost. Then when going through a small town I got complete cutout but as it happened I noticed the fuel pump die at the same time. Strangely I removed an 044 and fitted a M400 pump which is actually noisier so Im able to hear it when doddling around in town. So I know its either ECU power or fuel pump power. As I did the fuel pump mod at the weekend I will short out the relay and permanently feed the fuel pump and see how I get on. My laptop was flat this morning but will also connect the laptop to see if the ecu was switching the pump off/killing the original relay or if I lose connection with comms.
Wish me luck!!!
Hi Craig , there are some relays on the front bulkhead infront of the aircon compresser , these are very prone to getting full of water and rusting , one of them controls the fuel pump !! you need to pull of the drivers side wheel , remove the wheel arch trim and you will get access to the side pod , in there is the ecu and you get a good view of the bulkhead relays !! pull them out and have a look to see what condition they are in , good luck .
Tux
Tux
TuxMan said:
Hi Craig , there are some relays on the front bulkhead infront of the aircon compresser , these are very prone to getting full of water and rusting , one of them controls the fuel pump !! you need to pull of the drivers side wheel , remove the wheel arch trim and you will get access to the side pod , in there is the ecu and you get a good view of the bulkhead relays !! pull them out and have a look to see what condition they are in , good luck .
Tux
what he said... the stock fuel pump relay (and surrounding ones) are prone to water ingress and contact issues. its a very common problem and a thorough clean up of the connections and or replacement sorts.Tux
If the M400 is noisy go back to the 044 and don't let the fuel tank go below 1/3ish and all will be well... has the car been remapped? seems strange to have an 044 without it being upped in power!
Thanks again gents, Ill try shorting the modded relay for the fuel pump so its got permanent power. Then when I get home (I limped into work today) Ill try stripping out the relay bank.
Ive had the tank emptied when doing the pump then topped up with the expensive stuff! plus its gradually been getting worse over the last 2 weeks and three tanks of fuel.
As regards the pump, the car was originally Gary West's car, or Gaz something on here. I believe he was keen and looked after the car so would have been done in his ownership, the last owner just seems to have let everything fail around him. I dont think he had the power upped but was maybe planning this? It did seem quick compared to my 300bhp Exige but was putting this down to the torque.
I keep thinking about getting in touch with Gary to get an idea on what has and hasnt been done to the car.
Craig.
Ive had the tank emptied when doing the pump then topped up with the expensive stuff! plus its gradually been getting worse over the last 2 weeks and three tanks of fuel.
As regards the pump, the car was originally Gary West's car, or Gaz something on here. I believe he was keen and looked after the car so would have been done in his ownership, the last owner just seems to have let everything fail around him. I dont think he had the power upped but was maybe planning this? It did seem quick compared to my 300bhp Exige but was putting this down to the torque.
I keep thinking about getting in touch with Gary to get an idea on what has and hasnt been done to the car.
Craig.
The cutting out(as if starved of fuel) could be the ARV that is faulty, unplug the overflow/breather pipe from the neck of the fuel cap, try the car again.
If not then unplug the boost controller, its the one nearest the IC box attcahed to the plenum and the top is open to atmosphere.
If not then unplug the boost controller, its the one nearest the IC box attcahed to the plenum and the top is open to atmosphere.
Hey folks, apologies for the late reply but just back from south africa with work. Bit gutted as I wanted to go see where my car was born but didn't have time.
Anyway wanted to give an update just so anyone else with this problem will see a solution. To give some background I have a fair amount of experience with cars, not Noble but lots of Lotus and everything I thought pointed to electrical. I know a lot more now anyway!
So after cleaning all the contacts, redoing fuel pump wiring, fitting an M400 pump (and finding an 044!!), changing all the plugs no result, all that was left was the fuel pump hose. Honestly I though I was barking up the wrong tree but everyone here assured me as well as Jetstream that this was highly plausible. So this morning after receiving the correct pipe from Jetsream I drained the tank and fitted. Well bugger me sideways it worked!! Its wet and Ive only done around 15 miles but no stutter at all. Once it dries out Ill get some full throttle runs in the lower gears but its looking good.
Now for info, the pipe removed looks very similar to that from jetstream but with a few little differences. External diameter of the new pipe is only 20 mm with internal diameter of 15. Now the stuff that came off has the same ID but with 22m OD. You can actually tell the difference in the strength and flex of the two pipes. One thing worth noting is that the pipe remove has external braid only but the jetstream replacement appears to have a reinforced layer. If anyone is in doubt just get the correct pipe from JS as its not expensive and an easy fix.
So again, a massive thanks to everyone for their help and advice,
Cheers Craig.
Anyway wanted to give an update just so anyone else with this problem will see a solution. To give some background I have a fair amount of experience with cars, not Noble but lots of Lotus and everything I thought pointed to electrical. I know a lot more now anyway!
So after cleaning all the contacts, redoing fuel pump wiring, fitting an M400 pump (and finding an 044!!), changing all the plugs no result, all that was left was the fuel pump hose. Honestly I though I was barking up the wrong tree but everyone here assured me as well as Jetstream that this was highly plausible. So this morning after receiving the correct pipe from Jetsream I drained the tank and fitted. Well bugger me sideways it worked!! Its wet and Ive only done around 15 miles but no stutter at all. Once it dries out Ill get some full throttle runs in the lower gears but its looking good.
Now for info, the pipe removed looks very similar to that from jetstream but with a few little differences. External diameter of the new pipe is only 20 mm with internal diameter of 15. Now the stuff that came off has the same ID but with 22m OD. You can actually tell the difference in the strength and flex of the two pipes. One thing worth noting is that the pipe remove has external braid only but the jetstream replacement appears to have a reinforced layer. If anyone is in doubt just get the correct pipe from JS as its not expensive and an easy fix.
So again, a massive thanks to everyone for their help and advice,
Cheers Craig.
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