Brief stall in power output at high rpm
Discussion
Two weeks ago for three times I had a very brief stall in the power output when going flat out above 6000rpm. It was only very short and the engine picked up immediately after. Went driving yesterday to see if I got it again but that was not the case.
Do you guys think this could indicate that the 'gas valve holders' (sorry, don't know th English word, hope you know what I mean) need to be revised? Or could it just have been a batch of lesser quality fuel when I was forced to get some 95 octane fuel at a less-known gast station instead of my usual 98?
Do you guys think this could indicate that the 'gas valve holders' (sorry, don't know th English word, hope you know what I mean) need to be revised? Or could it just have been a batch of lesser quality fuel when I was forced to get some 95 octane fuel at a less-known gast station instead of my usual 98?
Yes that was exactly the thing. I hope it was just a random thing indeed. My TVR garage said that it might be those 'gas valve holders' because if there is a slight mismatch/misalignment and the ECU gets some wrong information it just cuts the engine power very shortly, or something like that. Does this make any sense? But they said there was no way to be sure it was that until they are taken out and revised. If they have to be taken out they have to be sent to England to be revised which means it will cost me three weeks and around 1000 pounds. Bit of an expensive gamble imo.
I presume "gas valve seals" in English is "valve seats"? Either way this is in no way the cause of the random cut-outs.
Others with this problem have been advised that it's a sign that the speedo transducer is failing, and a replacement has fixed it. I've had mine replaced but not had the opportunity to drive the car much since to verify, but so far so good.
It does sound though that your specialist is feeding you a pile of crap as it's definitely not a serious problem. The MBE ECU that TVR uses doesn't even have the functionality to do what your dealer is saying it's doing. TVR's are very simple cars and electronically are on par with a late 80's/early 90's mass produced car.
Others with this problem have been advised that it's a sign that the speedo transducer is failing, and a replacement has fixed it. I've had mine replaced but not had the opportunity to drive the car much since to verify, but so far so good.
It does sound though that your specialist is feeding you a pile of crap as it's definitely not a serious problem. The MBE ECU that TVR uses doesn't even have the functionality to do what your dealer is saying it's doing. TVR's are very simple cars and electronically are on par with a late 80's/early 90's mass produced car.
Could be a couple of other things to consider...the 'aircraft' style connector between the bulkhead and engine bay has been known by a few people recently to cause an unnerving momentary loss of all power, the connections inside can corrode and individual pins can be more prone than others.
Another thing (and what makes me suggest that you look at this is the fact that you get it at high RPM) may be the throttle bodies have worn.
When i first purchased my car i noticed that i had what appeared to be a misfire at 5500 RPM, and the car stuttered badly and suddenly, occasionally losing power completely momentarily. This was due to worn throttle bodies, what happens is, at high RPM if there is slack between the spindle of the throttle butterfly and the throttle body, the spindles vibrate. In turn this sends 1000's of signals to the throttle pot which in turn dumps a whole load of messed up data to the ECU. The ECU cant cope...and shuts itself down momentarily, hence the loss in power.
I resolved it with new roller bearing throttle bodies and new throttle pots.
I'm not saying this is your problem but the symptoms are similar in some ways so its worth checking out.
Hope you get to the bottom of it anyway
Another thing (and what makes me suggest that you look at this is the fact that you get it at high RPM) may be the throttle bodies have worn.
When i first purchased my car i noticed that i had what appeared to be a misfire at 5500 RPM, and the car stuttered badly and suddenly, occasionally losing power completely momentarily. This was due to worn throttle bodies, what happens is, at high RPM if there is slack between the spindle of the throttle butterfly and the throttle body, the spindles vibrate. In turn this sends 1000's of signals to the throttle pot which in turn dumps a whole load of messed up data to the ECU. The ECU cant cope...and shuts itself down momentarily, hence the loss in power.
I resolved it with new roller bearing throttle bodies and new throttle pots.
I'm not saying this is your problem but the symptoms are similar in some ways so its worth checking out.
Hope you get to the bottom of it anyway
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