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RPM's are jumping around!!!!?

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Old 07-29-2008, 02:25 PM
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Default RPM's are jumping around!!!!?

when i start my car and give it some gas the rph's jump around really bad and after the car is heated up its not as bad but still jumping???
Old 07-29-2008, 03:01 PM
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Default Re: RPM's are jumping around!!!!? (mclebed)

sounds like IACV is bad...or your TPS...those are my 2 suggestions
Old 07-29-2008, 03:08 PM
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Default Re: RPM's are jumping around!!!!? (mclebed)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mclebed &raquo;</TD></TR><TR><TD CLASS="quote">when i start my car and give it some gas the rph's jump around really bad and after the car is heated up its not as bad but still jumping???</TD></TR></TABLE>

Is it the actual RPM, or just the tachometer is jumping?

If it's just the tachometer, it's either a bad igniter in the distributor, or a loose wire on the igniter (it has slide-on connectors that can work lose, I found this the hard way.)

If it's RPM, I would check for vacuum leaks. Try pinching the hose to the PCV, brake booster, or anywhere else that has vacuum to the intake manifold.
Old 07-29-2008, 04:56 PM
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Default Re: RPM's are jumping around!!!!? (Chris F)

i had this problem. my engine would be running normal and my tach rpm would go crazy, sometimes going from zero to redline and back down, sometimes just sitting at zero, etc. i never managed to pinpoint the problem. but later on (a few weeks later), the problem got worse and my actual engine rpm starting acting up as well, even stalling at times. i replaced the coil and ICM, and the problem went away. but til today, my car keeps frying ICM's and coils and damn its a big headache. im about to replace the whole damn distributor.
Old 07-29-2008, 05:27 PM
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Default Re: RPM's are jumping around!!!!? (vtecb18c)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtecb18c &raquo;</TD></TR><TR><TD CLASS="quote">sounds like IACV is bad...or your TPS...those are my 2 suggestions</TD></TR></TABLE>

Ditto, check the idle air screw for play.
Old 07-29-2008, 08:11 PM
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Default Re: RPM's are jumping around!!!!? (ketchup)

100% Sure Dizzy
Old 07-30-2008, 02:50 AM
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Default Re: RPM's are jumping around!!!!? (JLeeBB4)

i had to same progblem and began once again yesterday...i changed most sensors related to the rpms...after brand new coil,icm and distrubutor the thing was still there. what makes it go away is when i yank the wires that go to the dizzy and back into the firewall. i yank to move wires around not to ripped them off. my assumption is that the wire that wires up to the tach and back to the ecu is lose. but to find that is a mission. try moving the wires around. i wasted tons of money for nor reason. prelude are notorious for electrical issues and he is one of them.

DVS luder the same issue could be yours and the wire might be touching baremetal and causing a short and frying of your icm...just a thought.
Old 07-30-2008, 07:36 AM
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Default Re: RPM's are jumping around!!!!? (Edul59)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edul59 &raquo;</TD></TR><TR><TD CLASS="quote">i had to same progblem and began once again yesterday...i changed most sensors related to the rpms...after brand new coil,icm and distrubutor the thing was still there. what makes it go away is when i yank the wires that go to the dizzy and back into the firewall. i yank to move wires around not to ripped them off. my assumption is that the wire that wires up to the tach and back to the ecu is lose. but to find that is a mission. try moving the wires around. i wasted tons of money for nor reason. prelude are notorious for electrical issues and he is one of them.

DVS luder the same issue could be yours and the wire might be touching baremetal and causing a short and frying of your icm...just a thought.</TD></TR></TABLE>

Dang i never heard of that.. Guess its good to know
Old 08-05-2008, 05:13 PM
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Default Re: RPM's are jumping around!!!!? (Chris F)

thanks bro
Old 08-05-2008, 05:13 PM
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Default Re: RPM's are jumping around!!!!? (DVS Luder)

thanks bro
Old 08-05-2008, 05:14 PM
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Default Re: RPM's are jumping around!!!!? (JLeeBB4)

thanks bro
Old 08-05-2008, 05:39 PM
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Default Re: RPM's are jumping around!!!!? (mclebed)

had the same problem, it turned out to be a bad dizzy. threw a new one on, problem solved.
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