90' V8Q surging under acceleration...
11-16-2008, 06:37 AM
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90' V8Q surging under acceleration...
So, it doesn't seem to matter what gear it's in or if it easy or hard acceleration... Sport mode, economy or manual. The engine surges very rhythmically and predictably.Fast, slow, fast, slow. Never sputters or anything like that and otherwise runs great. Any ideas?? It's definitely a little annoying and just feels like you can't keep a steady foot on the pedal or something???
11-16-2008, 11:27 AM
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Re: 90' V8Q surging under acceleration...
Oxygen sensor or fuel pressure regulator or both. Sometimes the idle stabilization valve can add to the mix.
If you don't know how old the Oxy sensor is, I'd start with that.
If you don't know how old the Oxy sensor is, I'd start with that.
11-16-2008, 08:17 PM
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Re: Clarification for a relative newbie... ISV???
Idle Speed Valve (motor) the round thing right in front of the motor. Two wires and three bolts.
Sometimes they get plugged up, and need a good cleaning. Sometimes the wirings gets funky.
<img src="http://www.justfourrings.com/phpBB2/files/today_207.jpg">
Right between the V at the front of the intake manifold. Round, Black about 4" long 2" dia.
Sometimes they get plugged up, and need a good cleaning. Sometimes the wirings gets funky.
<img src="http://www.justfourrings.com/phpBB2/files/today_207.jpg">
Right between the V at the front of the intake manifold. Round, Black about 4" long 2" dia.
04-16-2009, 09:03 AM
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Unplug your ISV? I put a new ISV in mine and it started to do this..had to use the old one which was properly sealed (and broken).... oculd have simply done a direct connect to remove the ISV from the loop. ONly issue is typically cold starts (requires some throttle) but once a bit warm all is well...not fixing that any time soon.
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04-16-2009, 09:15 AM
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yep.... i had same issue with ISV.. (newish isv died after couple of weeks yielding the surging up and down). RPobably was something else causing the issue that killed the ISV. I'm sure it wasn't Video that did it.
