Idle surge 1500 to 3200rpm

[Beauryan Best]

You are getting close. Dont give up. Electrical Intermittent issues are a challenge for anyone even Professionals.

okay!
Some progress... I opened up the bundle & pulled out the 4 prong (fuse/bus bars?) and they all had the slightest amount of corrosion. Cleaned them to base metal and cant replicate the codes.

but... my throttle is still sticking at 3200rpm. takes a few blips of the throttle and it drops back down.
Shaking these wires has no effect now. Smh.

In DIAG. mode the biggest irregularity is the ISC jumps from 60 (everything is fine) to 120 (high rpm). I found one forum about a similar issue, but he gave no resolve.

 

[Beauryan Best]

took it for a ride around the block (for the first time ever) and got no codes,
But
RPM issue still remains: 50% of the time it still idles at 3200 though... what could cause that?
TPS still reads 0% without the throttle lever being pulled = butterfly valves are closing

 

[Beauryan Best]

I wonder if the ISC is sticking open and causing more airflow... but I know for fact it is clean.

 

[Beauryan Best]

Ok, I used a long screwdriver as a stethoscope to listen to the ISC Valve. Turnbing the key ON I can hear the ISC open with authority. Key OFF I can hear the ISC close a little slower but it sounds like bubbles rising underwater (if that makes any sense), almost hydraulic... idk how that makes any sense it should be a dry unit, smh, is this normal?
with the motor running I can hear what sounds like the ISC Valve cycling at high speed (tick tick tick tick), matched with RPMs, which still sticks at 3200rpm when applied throttle... cant be stuck open can it?
I feel like I'm at a dead end and need some guidance

 

[Beauryan Best]

IT WAS MY IAC VALVE!
Swapped it out for an extra Nytro IACV I had sitting around, cleaned out the tiny ports nice n shiny with q tips and throttle cleaner, and now I can't replicate the RPMs sticking/surging.
I hope this helps the next guy, and I hope this headache doesn't happen to you.

- Issue #1 codes p0122 & p0120 I'm Certain were due to the bundle of 4 prong wires (Pictured Pg 1); I opened the connectors, pulled out 4 prong terminals, and cleaned miniscule corrosion to base metal. Codes Auto-Cleared.

- Issue #2 High Idle, "Surge". I'm Certain were due to faulty IAC valve &/or Dirty IAC Intake Ports. Take IACV off TB & look into the hole, make sure there is no black crap at*all*. Replace IACV (Nytro P/N works okay on Viper!) &/or clean TB nice and shiny with throttle-cleaner* and q-tips. Make sure before you screw in the IACV; that you plug it into the 6 prong connector, and turn the PWR Key ON & OFF a few times to cycle the IACV into it's automatic shutoff center (or risk damaging it if over extended), this will also test your IACV, now align IACV & screw in the 3 screws and don't drop them. I used a tiny $26 neodium magnet on the tip of my 2'ft philips #2 while guiding the screws out & in, they looked to be SS so not very ferrous. I had to remove down to the gas tank caps plastic panel to gain minimal but full & safe access. Q tipping it clean with minimal space might scratch up your hand, you'll have to remove the tank or A frame if otherwise.

 

[Yamasledder]

IT WAS MY IAC VALVE!
Swapped it out for an extra Nytro IACV I had sitting around, cleaned out the tiny ports nice n shiny with q tips and throttle cleaner, and now I can't replicate the RPMs sticking/surging.
I hope this helps the next guy, and I hope this headache doesn't happen to you.

- Issue #1 codes p0122 & p0120 I'm Certain were due to the bundle of 4 prong wires (Pictured Pg 1); I opened the connectors, pulled out 4 prong terminals, and cleaned miniscule corrosion to base metal. Codes Auto-Cleared.

- Issue #2 High Idle, "Surge". I'm Certain were due to faulty IAC valve &/or Dirty IAC Intake Ports. Take IACV off TB & look into the hole, make sure there is no black crap at*all*. Replace IACV (Nytro P/N works okay on Viper!) &/or clean TB nice and shiny with throttle-cleaner* and q-tips. Make sure before you screw in the IACV; that you plug it into the 6 prong connector, and turn the PWR Key ON & OFF a few times to cycle the IACV into it's automatic shutoff center (or risk damaging it if over extended), this will also test your IACV, now align IACV & screw in the 3 screws and don't drop them. I used a tiny $26 neodium magnet on the tip of my 2'ft philips #2 while guiding the screws out & in, they looked to be SS so not very ferrous. I had to remove down to the gas tank caps plastic panel to gain minimal but full & safe access. Q tipping it clean with minimal space might scratch up your hand, you'll have to remove the tank or A frame if otherwise.

Nice work. These gremlins can sometimes be next to impossible to track down. Codes don't always tell the story either. Perseverance and a little luck can go a long way toward finally coming across something that just doesn't seem right.

 

[Beauryan Best]

Thanks man,
Had an 8 hour Powerpoint class on the word, "Resilience," once lol...
I think I'm going to check and clean these annually to avoid carbon build up for now on... honestly just been scared to take the IACv off because the Repair Manual almost specifically says "do not f with it; and to buy a brand new throttle body for $500-700"... mentally daunting but came out just fine, seemingly low risk, and would even suggest the Reader do the same

Nice work. These gremlins can sometimes be next to impossible to track down. Codes don't always tell the story either. Perseverance and a little luck can go a long way toward finally coming across something that just doesn't seem right.