Odd Acceleration Issue & Occasional Pulsing Idle

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So are you still having the sputtering issue at launch? Bad idle? Just wondering if those O2 values were with the issue present or not.

Frank
 

SmokingRocks

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No, I think it is the IAC valve, it's not responsive, I've got a new one coming. But I figured I'd get some practice in with my new Picoscope toy.
 

SmokingRocks

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I fixed the IAC valve, the internal washers had degraded to the point where the valve would get jammed in the closed position. Digging through my spares box I was able to get a solution that worked. So now the valve is back in service and working great. I'll update the post in a couple of days to verify this was the issue. Thanks for the help, especially @elripster

Also your google sheet is pretty neat, I've saved a copy for my use.
 
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Awesome! 2 more 80's back in shape.

Frank
 
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I don't think a Bosch O2 sensor is an upgrade, but that is just my opinion. I would only use Toyota or Denso for the O2 sensors, and an improper air/fuel mixture seems like it would explain the OP's symptoms. Just a thought.
 

SmokingRocks

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Check the scoping work done on the previous page @bicycleagent003, specifically the last post on that page. The 02 sensors are singing perfectly and the problem was traced back to the IAC.
 
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I don't think a Bosch O2 sensor is an upgrade, but that is just my opinion. I would only use Toyota or Denso for the O2 sensors, and an improper air/fuel mixture seems like it would explain the OP's symptoms. Just a thought.

I don't know that an O2 can be said to be an upgrade. I had a Denso go bad in 1000 miles just this weeks. No obvious reason for it. The controller doesn't know what brand is in there. It just expects things like ranges and ratios between the MAF and O2 levels, etc... to comply with thresholds or it will throw a lean/rich fault. The Delphi's I installed, only because Rock Auto had them in stock for good price, have cleared the faults, reduced fuel consumption, increase power, and the idle is buttery smooth.
 

SmokingRocks

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Well in this case it is an upgrade (in terms of reliability and life span) as the Bosch sensor I am using is a Planer style vs the OEM thimble style. Pretty common mod for the OBD1 and SC'd guys, check it out here: O2 Sensor Replacement - 1994 FZJ80
 
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Excellent link. It looks like the Delphi's are also planar. If the link is believed they are the best out there but there is always a bit of salesmanship going on there...


Frank
 

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