Help! My T350C is suddenly running rough....
Discussion
Hi,
I've just got back from giving my newly acquired t350c a run after I've been away on holiday.
I was just giving it some acceleration up a hill (6000rpm) after it had warmed up - oil at 80C - when suddenly it started sounding rough and lost power, as if some of the cylinders weren't firing? This happened instantly.
This seemed to coincide with hitting a bit of an undulation in the road during acceleration. Oil pressure appears to be as normal, water temp is normal, and I've checked the oil which is still on max.
The engine doesn't seem to be making any nasty sounding mechanical noises (no knocking or tappety noises). There are no error messages being displayed. It sounds quite stuttery and rough at low revs but evens out a bit at slightly higher revs.
Does anyone have any idea as to what it may be? Tried looking for spark plug leads but I'm guessing these are hidden beneath the engine cover? My engine warranty has about another 2 weeks left to run.
Please let it not be the engine gone pop :(
P.S. Does anyone know exactly what the 2nd Year Engine warranty covers (i.e. does it cover electrics etc.)?
I've just got back from giving my newly acquired t350c a run after I've been away on holiday.
I was just giving it some acceleration up a hill (6000rpm) after it had warmed up - oil at 80C - when suddenly it started sounding rough and lost power, as if some of the cylinders weren't firing? This happened instantly.
This seemed to coincide with hitting a bit of an undulation in the road during acceleration. Oil pressure appears to be as normal, water temp is normal, and I've checked the oil which is still on max.
The engine doesn't seem to be making any nasty sounding mechanical noises (no knocking or tappety noises). There are no error messages being displayed. It sounds quite stuttery and rough at low revs but evens out a bit at slightly higher revs.
Does anyone have any idea as to what it may be? Tried looking for spark plug leads but I'm guessing these are hidden beneath the engine cover? My engine warranty has about another 2 weeks left to run.
Please let it not be the engine gone pop :(
P.S. Does anyone know exactly what the 2nd Year Engine warranty covers (i.e. does it cover electrics etc.)?
If your car's done around 14K miles, it may be time for the throttle pots to be changed, I had the same prob last year, stuttering on acceleration, sounded terrible, bought a set of pots from TVR power (about £70 for the 2), got local dealer to put them on, and I had new HT leads and plugs done at the same time, and has been fine since! 
I hope your's is as simple
I hope your's is as simple
It does sound like something has come unstuck/loose somewhere. I've not investigated all the way but it looks like the HT leads go around under the air filter so if you remove it you might be able to see them and the coil packs (or maybe the coil packs are somewhere completely different).
Are you in the AA? Pretend it wouldn't start, call them. When the man arrives say you just managed to get it going and let him prod around and check all the connections for you
Are you in the AA? Pretend it wouldn't start, call them. When the man arrives say you just managed to get it going and let him prod around and check all the connections for you
rob172 said:
Thanks everyone for the help. Does anyone know definetly where the coil packs are located so I can check the connections?
I don't want to drive the car for fear of destroying the cat with unburnt petrol.
Thanks.
You have to take the Air box out to get to them, they are on the underneath on the left. WORD OF WARNING, do not start the car up without the air sensor being connected, its the little conector on top of the air box, or you will get an EFI fault, which can only be cleared by a dealer with the engine management software!!!
You may have just pulled some shit up in the fuel tank if the fuel was low too, but it does sound like electrics, or HT lead faulire. Two years under the bonnet in the heat will fry them
If you change them get some Magnecors
Thanks again for the help, it is much appreciated.
I'll have a good look at it tonight, hopefully the air filter won't be too troublesome to remove.
I'm trying to get in touch with SFR in Stockport as well to see if they can look at it but I'm just getting their answering machine. I guess they are very popular!
I'll have a good look at it tonight, hopefully the air filter won't be too troublesome to remove.
I'm trying to get in touch with SFR in Stockport as well to see if they can look at it but I'm just getting their answering machine. I guess they are very popular!
Ok, just had a good look over the car. Checked all the fuses were pushed home firmly, looked at all the connections I could see, injectors etc.
I'm a bit reluctant to remove the air filter after looking at it. It seems to have all sorts of things attached to it including the intake manifold etc. The clamps are also cable tied on. Don't seem to be able to see any of the ignition leads, I assume they are well and truly hidden underneath the air filter?
After prodding, banging (always works!) everything I gave it a try.
What seemed to happen is that it started normally and would respond as usual to a gentle blip on the throttle. After about 10-15 seconds it began to get rough again until eventually after another 10-15 seconds it was just as rough as before.
What could explain it being ok at first start up and then starting to miss?
Thanks
P.S. Like Nick I have the knock sensor connectors (front and rear) just hanging disconnected. I also have a disconnected connector hanging in the footwell with red pink and black wires. That couldn't be anything to do with it could it?
Rob (under wifes profile!)
>> Edited by Em_ on Wednesday 22 June 21:23
I'm a bit reluctant to remove the air filter after looking at it. It seems to have all sorts of things attached to it including the intake manifold etc. The clamps are also cable tied on. Don't seem to be able to see any of the ignition leads, I assume they are well and truly hidden underneath the air filter?
After prodding, banging (always works!) everything I gave it a try.
What seemed to happen is that it started normally and would respond as usual to a gentle blip on the throttle. After about 10-15 seconds it began to get rough again until eventually after another 10-15 seconds it was just as rough as before.
What could explain it being ok at first start up and then starting to miss?
Thanks
P.S. Like Nick I have the knock sensor connectors (front and rear) just hanging disconnected. I also have a disconnected connector hanging in the footwell with red pink and black wires. That couldn't be anything to do with it could it?
Rob (under wifes profile!)
>> Edited by Em_ on Wednesday 22 June 21:23
I have a small connector in the footwell, hanging near the fuse panel. I think I also have the knock sensor cables un-used too.
If it runs OK for a short while I think you can rule out anything mechanical, and breathe more easily.
After 10-15 seconds I would think the ECU is failing to get a signal from a sensor and thus adjusting the mixture or timing or whatever for the wrong conditions. So I suggest you keep looking.
Of course the bump could have simply knocked a sensor out of action instead of breaking a connection. A dealer diag system should be able to identify the culprit.
If it runs OK for a short while I think you can rule out anything mechanical, and breathe more easily.
After 10-15 seconds I would think the ECU is failing to get a signal from a sensor and thus adjusting the mixture or timing or whatever for the wrong conditions. So I suggest you keep looking.
Of course the bump could have simply knocked a sensor out of action instead of breaking a connection. A dealer diag system should be able to identify the culprit.
Just an update. I've booked it in at HL Gorners for tomorrow morning. Going to get it relayed via the AA as I don't want to damage the cat. They are going to plug it into their diagnostics but say they might not have time to fix on the day.
Fingers crossed it's something simple.
Is it worth me letting the AA have a look at it before they relay it or are they likely just to damage something?
Thanks.
Rob.
Fingers crossed it's something simple.
Is it worth me letting the AA have a look at it before they relay it or are they likely just to damage something?
Thanks.
Rob.
Em_ said:
Ok, just had a good look over the car. Checked all the fuses were pushed home firmly, looked at all the connections I could see, injectors etc.
I'm a bit reluctant to remove the air filter after looking at it. It seems to have all sorts of things attached to it including the intake manifold etc. The clamps are also cable tied on. Don't seem to be able to see any of the ignition leads, I assume they are well and truly hidden underneath the air filter?
After prodding, banging (always works!) everything I gave it a try.
What seemed to happen is that it started normally and would respond as usual to a gentle blip on the throttle. After about 10-15 seconds it began to get rough again until eventually after another 10-15 seconds it was just as rough as before.
What could explain it being ok at first start up and then starting to miss?
Thanks
P.S. Like Nick I have the knock sensor connectors (front and rear) just hanging disconnected. I also have a disconnected connector hanging in the footwell with red pink and black wires. That couldn't be anything to do with it could it?
Rob (under wifes profile!)
>> Edited by Em_ on Wednesday 22 June 21:23
The two knock sensors are leftovers from the wiring loom that the car was stolen from. They are not used on the TVR, so dont worry worry about them...
Mr F
Well I've had to cancel the trip to HL Gorners as the AA insisted on a 24 hour period before I could use my upgraded relay membership......
I'm going to call the AA tomorrow to come and have a look at it.
Is there really only the two brackets holding on the air filter and the pipes that are feeding into it?
Thanks.
Rob.
I'm going to call the AA tomorrow to come and have a look at it.
Is there really only the two brackets holding on the air filter and the pipes that are feeding into it?
Thanks.
Rob.
Just a quick update.
Took the car in this morning to the dealers on the back of an AA low loader. They have spent 2 hours on it so far and found nothing.
Getting worried now as it's going to be costing me big time for labour. They say they've tried a new coil and that made no difference.
They are now going to take the exhaust of to see if that is blocked??
The car runs fine for the first 10-15secs after it starts up and then progressively gets rougher and rougher. Surely there must be a simple cause to this? The problem happened instantly as we were accelerating and hit a slight undulation, no grounding took place. I asked if it was running rich and he said it was showing nothing? Is it not possible to test the exhaust gas and the sparking to narrow it down?
Any ideas I could pass on that might save me some hard earned?
Thanks.
Rob.
Took the car in this morning to the dealers on the back of an AA low loader. They have spent 2 hours on it so far and found nothing.
Getting worried now as it's going to be costing me big time for labour. They say they've tried a new coil and that made no difference.
They are now going to take the exhaust of to see if that is blocked??
The car runs fine for the first 10-15secs after it starts up and then progressively gets rougher and rougher. Surely there must be a simple cause to this? The problem happened instantly as we were accelerating and hit a slight undulation, no grounding took place. I asked if it was running rich and he said it was showing nothing? Is it not possible to test the exhaust gas and the sparking to narrow it down?
Any ideas I could pass on that might save me some hard earned?
Thanks.
Rob.
I too took my Tam to be diagnosed when mine was running rough last year, and twice the dealers said there was nothing wrong with it! It took an email to Dom at TVR Power, explaining the symptoms, to get an answer (throttle pots), and sure enough, once changed, the car ran perfect!
Moral of the story is, don't always trust what the dealers tell you!
Moral of the story is, don't always trust what the dealers tell you!
Dear all,
Thanks for the help.
The fuel pump sounds like a major possible, especially considering the car will start ok (fuel pump primes before switch on so engine will have plenty of fuel initially available) and even when the car is running rough (after 10-15 secs) it still seems to idle ok, only when revved does it sound rough (no power).
I've also thought of something else. I'd only recently filled up with optimax the previous night, previously (2 years) as far as I know it had only been run on bp stuff. Could this be a problem? Hang on optimax cleans things, I wonder..... Does the fuel pump have a filter???? Could this be blocked? Hmmmmmmmmm. Giving it a bit of stick so pumping plenty of fuel, go over bump which dislodges crap helped by optimax and this ends up in the fuel pump starving engine of fuel? What do you reckon?
It's a bit like a detective story this. I'd be enjoying it if it wasn't costing me an arm and a leg for someone to try random things!!!!
Chris did the throttle pot problem occur instantly or just over time? Mine is running majorly rough i.e. not driveable and it happened instantly.
Going to phone first thing tomorrow, probably get on their nerves but hey when its costing me an arm and a leg I don't care. I want to know in detail what they have tested so far. I bet they haven't tested the fuel pump!
Thanks all.
Thanks for the help.
The fuel pump sounds like a major possible, especially considering the car will start ok (fuel pump primes before switch on so engine will have plenty of fuel initially available) and even when the car is running rough (after 10-15 secs) it still seems to idle ok, only when revved does it sound rough (no power).
I've also thought of something else. I'd only recently filled up with optimax the previous night, previously (2 years) as far as I know it had only been run on bp stuff. Could this be a problem? Hang on optimax cleans things, I wonder..... Does the fuel pump have a filter???? Could this be blocked? Hmmmmmmmmm. Giving it a bit of stick so pumping plenty of fuel, go over bump which dislodges crap helped by optimax and this ends up in the fuel pump starving engine of fuel? What do you reckon?
It's a bit like a detective story this. I'd be enjoying it if it wasn't costing me an arm and a leg for someone to try random things!!!!
Chris did the throttle pot problem occur instantly or just over time? Mine is running majorly rough i.e. not driveable and it happened instantly.
Going to phone first thing tomorrow, probably get on their nerves but hey when its costing me an arm and a leg I don't care. I want to know in detail what they have tested so far. I bet they haven't tested the fuel pump!
Thanks all.
My throttle pots got progressively worse, the engine seemed to eventually stutter and judder all the time, I did fear fear the worse, but it turned out to be the pair of pots that cost about £70! Dom at TVR Power told me they last about 14K miles, and need changing. I will buy another pair this year, and ask for them to be replaced at my next big service (for piece of mind)
chris watton said:
My throttle pots got progressively worse, the engine seemed to eventually stutter and judder all the time, I did fear fear the worse, but it turned out to be the pair of pots that cost about £70! Dom at TVR Power told me they last about 14K miles, and need changing. I will buy another pair this year, and ask for them to be replaced at my next big service (for piece of mind)
Isnt there some available with propper bearings? I remember reading about it somewhere and that they not only last longer and give much better idling..?
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