Engine Holds Rpms Too Readily
05-02-2005, 04:47 PM
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I'm not sure if this is just how the Tib engine is made, but I noticed it especially with my 5 speed 2001 Tiburon.
The engine holds rpms for a while after you stop accelerating, namely at high rpms after taking your foot off the gas. This interferes with shifting, as the rpms don't drop at a suitable pace for a reasonably steady shift. I would have to wait for a second and a half or more for the rpms to drop to a suitable place for the next gear. If I shift and clutch out relatively quickly, the car lugs and rocks back in forth as the transmission components level out to each other.
I've driven my friend's manual 3000gt before and once you take your foot off the gas, the rpms drop, making for smoother and faster shifts. Now, is there anyway I can fix this? I've heard it might be connected to a heavy fly wheel or the like, but any suggestions?
The engine holds rpms for a while after you stop accelerating, namely at high rpms after taking your foot off the gas. This interferes with shifting, as the rpms don't drop at a suitable pace for a reasonably steady shift. I would have to wait for a second and a half or more for the rpms to drop to a suitable place for the next gear. If I shift and clutch out relatively quickly, the car lugs and rocks back in forth as the transmission components level out to each other.
I've driven my friend's manual 3000gt before and once you take your foot off the gas, the rpms drop, making for smoother and faster shifts. Now, is there anyway I can fix this? I've heard it might be connected to a heavy fly wheel or the like, but any suggestions?
05-02-2005, 04:52 PM
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At what rpm does your car usualy hold at? If it holds aruond 1500 (give or take some) that's normal. I'm guessing you have a stock TB. If you have an aftermarket TB and noticed a big difference with the idle, then you will have to adjust your idle screw and/or throttle cables.
05-02-2005, 04:58 PM
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My car does the same and I have the VHR forged aluminum flywheel, as well as the RSide BBTB and a bored IM to match. I'll shift out of gear and the rpm's will drop some, maybe hang at like 2.5k, then drop some more and hang around 1.5k. If anything changes when I get my new engine I'll let you know wink1.gif
05-02-2005, 04:59 PM
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From what you describe about the revs not falling from High RPMs is NOT normal. While it should take a few moments for it to fall from 6750 back to 1000rpms.. taking a couple of seconds to drop 2thousand revs so you can shift is too long. Check your throttle body for any gumming around the cable and the pivot. Also, check the throat for any gunk as well that could interfere with the movement of the throttle plate. Also, how is your Throttle Position Sensor? Does it give you any problems at all?
05-02-2005, 05:03 PM
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QUOTE (Mad-Machine @ May 2 2005, 10:59 PM)
From what you describe about the revs not falling from High RPMs is NOT normal. While it should take a few moments for it to fall from 6750 back to 1000rpms.. taking a couple of seconds to drop 2thousand revs so you can shift is too long. Check your throttle body for any gumming around the cable and the pivot. Also, check the throat for any gunk as well that could interfere with the movement of the throttle plate. Also, how is your Throttle Position Sensor? Does it give you any problems at all?
Well it's not really several seconds but, say I rev to 5000 rpms. When I take my foot off the car will hang around 5000 then fall pretty steadily, but it hangs for just slightly less than a whole second. Even after that, the rpms don't fall nearly as fast as other cars I've driven. If you could explain all these places to check that would be great, I'm not really a mechanic.
05-02-2005, 05:21 PM
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hmmm.. your second explanation actually sounds closer to how these cars are normally. As they have a very heavy flywheel and harmonic balancer, having a razor sharp thottle response is not something more modern engines are known for. I begin to think you need to slow your shifting some.
05-02-2005, 05:25 PM
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It's not uncommon for the car to hold around 1500rpms and then drop to idle when the car comes to a complete stop. I have a forged flywheel and that baby drops pretty quickly but slows a bit when it hit 2000rpms.
05-02-2005, 06:51 PM
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Vehicle: 2000 Hyundai Tiburon
Somtimes at a stop sign my RPMs rev from 2500-3000. This stops when I start moving, but it makes me mad somtimes and I get looks from people when my car just sits there in traffic going "vrooom, vrooom, vrooom, vrooom, vrooom, vrooom"
05-02-2005, 07:10 PM
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QUOTE (Mad-Machine @ May 2 2005, 11:21 PM)
hmmm.. your second explanation actually sounds closer to how these cars are normally. As they have a very heavy flywheel and harmonic balancer, having a razor sharp thottle response is not something more modern engines are known for. I begin to think you need to slow your shifting some.
Well then a normal smooth shift would require me to complete the whole shifting process is close to three seconds. That can't be normal.