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pushkick
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Joined: August 09, 2007
Posts: 1366
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 Posted: Thu Apr 12, 2018 3:44 pm Post subject: Re: high idle and reving |
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here are my latest measurements. it seems that now i have 450ma on isv and before i was getting only 150 -200 ma . i have disconnected the ps sw and a/c sw. it seems i may have an intermittent signal from the temp sensor or power, or coil/diz. ran engine for 30 mins @ idle and 2000+ rpms then idle started going up and then unplugged the isv and idle went to normal them plugged isv back in and idle stayed normal ! need to make this happen again and then look at signal to isc. maybe isv is going bad. couldnt find a new one at gw or vc. one guess at this point is the windings in the isv (solenoid) heat up due to plunger wear or insulation of windings degradation. second guess is isc isnt working properly after running for awhile. someone who has a good isv could you please check resistance on pins and pin to casing? 3rd guess is a loose connection somewhere and is intermittently breaking connection.
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i see said the blind man to his deaf dog
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1990 vw automatic camper |
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pushkick
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Joined: August 09, 2007
Posts: 1366
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| Posted: Sun Apr 22, 2018 12:46 pm Post subject: Re: high idle and reving |
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since the idle goes up after the engine is warm and has been run at 2000-3000rpm and the air from afm is going into the isv. basically it bypasses the thriottle body. the pic of the system in pro training manual shows air going into isv from afm by passing the throttle body.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Mon May 21, 2018 5:22 pm Post subject: Re: high idle and reving |
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i put an oscilloscope on the diz signal to isc and it seems to be within spec at idle and 2000-3000 rpm. the signal to isv seems to be a steady pulse that dosent change duty cycle when engine is revved but it is a nice square wave pulse of 1.5ms every 5ms. no matter the rpm. i need to check signal after engine gets up to speed. i think i read in another thread that the signal to isv was a pulse width modulated signal but the signal i was looking at that did not happen. now i noticed that when i simulated power steering sw activation (jumpered it) there was some pulse width modulation or pulse width increase to about 2ms and the engine rpm increased.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Sun May 27, 2018 10:44 am Post subject: Re: high idle and reving |
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has anyone used a eurovan isv on a waterboxer? looks like the same unit.
i found this one on ebay
https://www.ebay.com/itm/New-Idle-Air-Control-Valv...1773015388
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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dobryan
Samba Member
Joined: March 24, 2006
Posts: 16503
Location: Brookeville, MD
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| Posted: Sun May 27, 2018 12:03 pm Post subject: Re: high idle and reving |
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Same symptoms here on my new to me 1991. Ran fine for 1600 miles from Denver to Maryland. Then Friday I drove 30 miles to pick up a part and the last 5 miles the engine was surging while driving, and at 'idle' it would bounce from 1000 to 3000 rpms in a few seconds, lather rinse repeat. At the fellows house the idle then spiked at 4000 rpm and held there. No mechanical source found but disconnecting the ISV wiring dropped the idle to normal. Drove home fine. Currently running without the ISV connected to the harness.
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'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD
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pushkick
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Joined: August 09, 2007
Posts: 1366
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| Posted: Sun May 27, 2018 12:49 pm Post subject: Re: high idle and reving |
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| dobryan wrote: |
| Same symptoms here on my new to me 1991. Ran fine for 1600 miles from Denver to Maryland. Then Friday I drove 30 miles to pick up a part and the last 5 miles the engine was surging while driving, and at 'idle' it would bounce from 1000 to 3000 rpms in a few seconds, lather rinse repeat. At the fellows house the idle then spiked at 4000 rpm and held there. No mechanical source found but disconnecting the ISV wiring dropped the idle to normal. Drove home fine. Currently running without the ISV connected to the harness. |
that is exactly what i am doing right now. but i am trying to troubleshoot the isc and isv signals to try and determine the component that is not working properly. i found that the isc was faulty in my van so i found a used one that worked and i replaced the power steering sw and that got rid of the bouncing rpm. but i am still running around 2000 rpm with the isv connected and i have disconnected the a/c and the ps sw and checked the tps at the isc and the diz signal and temp signal. every thing seems fine. the current to isv is around 450 ma which is where it is suppose to be according to bently.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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Aryana
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Joined: November 09, 2015
Posts: 568
Location: Southern CA
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| Posted: Mon May 28, 2018 12:28 am Post subject: Re: high idle and reving |
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| Just replace the idle stabilization valve. You’ll see... |
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pushkick
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Joined: August 09, 2007
Posts: 1366
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| Posted: Fri Jun 01, 2018 4:23 pm Post subject: Re: high idle and reving |
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| Aryana wrote: |
| Just replace the idle stabilization valve. You’ll see... |
well i just changed the isv and it looks like it has solved the problem. idle is back to around normal. i havent ran the engine at 2000-3000 for 30 min to see if it stays working at when engine gets to temp. will have to take for a long drive.
very difficult trouble shoot these devices. need to check air flow and electrical functionality. since this system is an open loop system it is difficult to trouble shoot since there is no measurement of air flow through unit.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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Aryana
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Joined: November 09, 2015
Posts: 568
Location: Southern CA
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| Posted: Fri Jun 01, 2018 6:51 pm Post subject: Re: high idle and reving |
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Yep. I parked in front of Van Cafe replacing literally everything before I tried replacing the ISV which was the culprit.
It hummed and made me think it was ok, but a known good one from another van is the only way to troubleshoot if yours is bad. |
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pushkick
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| Posted: Mon Jun 04, 2018 12:33 pm Post subject: Re: high idle and reving |
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this is very disappointing seems the isv helped on start and acceleration but after running for 30 min at 2500-3000 rpm then same old thing idle would stay around 1500 - 2000 rpm while idling , runs fine when cold. i changed the temp sensor i guess i will disconnect temp sensor at isc and see if that changes things or what effect it has on the isc operation. as i noted earlier the throttle body has the groves in the butterfly and where it meets the throttle body housing.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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Aryana
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Joined: November 09, 2015
Posts: 568
Location: Southern CA
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| Posted: Mon Jun 04, 2018 12:54 pm Post subject: Re: high idle and reving |
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| Do you have a copy of the Digifant Pro training manual? |
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pushkick
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Joined: August 09, 2007
Posts: 1366
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| Posted: Mon Jun 04, 2018 3:57 pm Post subject: Re: high idle and reving |
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| Aryana wrote: |
| Do you have a copy of the Digifant Pro training manual? |
yep sure do but i have stepped through most of the troubleshooting and i have either missed something/overlooked something. i dont know what to look for next.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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Aryana
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Joined: November 09, 2015
Posts: 568
Location: Southern CA
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| Posted: Mon Jun 04, 2018 8:14 pm Post subject: Re: high idle and reving |
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Try unplugging the ICV and install something inside the tube from the ICV to the intake boot to plug the flow and see how it runs.
This completely takes the ICU circuit out of operation and lets you possibly isolate the root cause. |
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pushkick
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Posts: 1366
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| Posted: Sat Jun 23, 2018 2:37 am Post subject: Re: high idle and reving |
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i am going to change the throttle body for a different one (newer no signs of wear) since the old throttle body has signs of wear and i dont seem to be able to adjust the idle to slow down with the idle screw even though it is turned all the way cw. will see if this helps.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Sat Jun 23, 2018 2:39 am Post subject: Re: high idle and reving |
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| Aryana wrote: |
Try unplugging the ICV and install something inside the tube from the ICV to the intake boot to plug the flow and see how it runs.
This completely takes the ICU circuit out of operation and lets you possibly isolate the root cause. |
i am going to try this and see what happens just got to figure out how to plug tube maybe rubber stoppers.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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pushkick
Samba Member
Joined: August 09, 2007
Posts: 1366
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| Posted: Fri Jul 06, 2018 4:59 pm Post subject: Re: high idle and reving |
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seems like the new throttle body has helped with the high idle after running @ 2500-3000 rpm for 20-30 min. ran down the freeway and didnt have the high idle when i got off the interstate. so new icv and isv and newer throttle body that wasnt worn seems like it has solved the problem. thanks for everyone input and advice. sometimes these problems are very difficult to troubleshoot with the bently procedures due to multiple worn or failing parts/devices.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper |
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