Revs rise in neutral
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Revs rise in neutral
So I was driving down the expressway just now, hit about 7500 rpm, and then pulled onto a side street. I noticed that when I pushed in the clutch, the revs would slowly rise up to about 2200. They never went above about 1500 before. Anytime the clutch was in or the car was in neutral, the revs would rise up like the AWS was engaged. A blip of the throttle would send the revs up and then they'd drop to about 1400, and rise right back up again. The car still pulled just as strong as ever, just now it wanted to rev to 2200 in neutral. I was thinking the AWS was acting up, or maybe I popped off a vacuum hose? Any ideas? Also, after shutting the car off and starting it again, revs went 1300, up to 1500, 1300, 1500, 1300, etc, fluctuating between the two.
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im not sure but right now my car is doing the opposite. When the clutch is in, the rpm drops like crazy. and once I was going somewhere and the car just shut off while I was stopped on the red light. Im thinking the problem might be the vaccum holes or I might just need a rebuilt. I have to take it to the shop and get it checked up.
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Originally Posted by enigma662
So I was driving down the expressway just now, hit about 7500 rpm, and then pulled onto a side street. I noticed that when I pushed in the clutch, the revs would slowly rise up to about 2200. They never went above about 1500 before. Anytime the clutch was in or the car was in neutral, the revs would rise up like the AWS was engaged. A blip of the throttle would send the revs up and then they'd drop to about 1400, and rise right back up again. The car still pulled just as strong as ever, just now it wanted to rev to 2200 in neutral. I was thinking the AWS was acting up, or maybe I popped off a vacuum hose? Any ideas? Also, after shutting the car off and starting it again, revs went 1300, up to 1500, 1300, 1500, 1300, etc, fluctuating between the two.
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Found it! I got lucky, it was right on the top on that little black box. (See first pic) However, after putting it back on, the car still had the same problem. I took another look, and realized that it had also split at the bottom of the hose as well as coming off the top. (Dead center 2nd pic) Is there somewhere (Mazda dealer?) that I can get a single replacement, or do I have to buy the whole kit from rx7store?
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Damnit! While taking the ripped piece of the hose off of the lower nipple so I could go to Autozone and replace it, I noticed there was another vacuum nipple next to it that was also empty! I can't find where it goes either... does anyone know? It's the one in the center of this pic, kinda hard to see.
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Haha yeah I probably did, I just replaced the broken one, but the problem didn't go away. The turbos both still work fine, seems to make full boost, it just has a funny idle. The weird thing is, the idle is affected by what's running on the car. With everything off, the idle is at 1600, and blips to 1700 about every two seconds. With the A/C on, it blips about once a second. With the lights switched to running lights or headlights, the idle rises to 2500 and stays steady. I think I'm gonna have to take it to Rick's Rotary lol.
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Check your butterfly valves in your intake manifold to make sure they are not
getting stuck open. if they are just give them a cleaning and send her on the
way.
JP
getting stuck open. if they are just give them a cleaning and send her on the
way.
JP
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Talked to Rick on the phone today, he says it may be a piece of the OEM intake manifold gasket causing an air leak. Gonna take it in Friday, have it checked out, I'll update then.
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Originally Posted by Gadd
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Well, took it to Rick's Rotary Performance, diagnosis: piece of the intake manifold gasket ripped off, I now have a vacuum leak. Front rotor is running lean, and gas and air are escaping... Estimate: $1250, turbos and rats nest have to be removed. Can't afford it right now, should I just save for a while and do a rebuild?
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holy crap. Ricks Rotary charges 1250 for replacement of the LIM gasket? Damn, I'm in the wrong business....
A bad LIM gasket does make sense based on your symptoms. The rats nest does not need to be removed for this job, but the turbos do. If you are somewhat mechanically inclined, you can do the work yourself. It's kind of time consuming, and will have you swearing every once in a while, but it's definitely doable. Would probably take just a couple of weekends of your time, and a few hundred bucks worth of parts (The gasket and any other odds and ends you may break during the process).
A bad LIM gasket does make sense based on your symptoms. The rats nest does not need to be removed for this job, but the turbos do. If you are somewhat mechanically inclined, you can do the work yourself. It's kind of time consuming, and will have you swearing every once in a while, but it's definitely doable. Would probably take just a couple of weekends of your time, and a few hundred bucks worth of parts (The gasket and any other odds and ends you may break during the process).