×
ScannerDanner Premium Customer Support (15 Mar 2019)

Please add This email address is being protected from spambots. You need JavaScript enabled to view it. as a contact in your email system. I am having a very hard time communicating with some of you because my reply messages are ending up in your spam folder! So please check your spam folders too!

× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

1997 Honda Civic 1.6 surging idle up and down

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
04 Apr 2019 18:49 #28426 by MOROSO321
So with this vehicle I changed the iac and bled the cooling system and the idle continues to go up and down. What did I do wrong. Iac is brand new. I tried adjusting the idle screw in and out, but it achieved nothing. Thanks.

Please Log in or Create an account to join the conversation.

More
04 Apr 2019 23:14 #28433 by guafa
Hi moroso,

You should check for a vacuum leak or any broken hose connected to intake manifold.
The following user(s) said Thank You: Chad

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 04:59 #28434 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
Ok thank you. I will. But this particular throttle body doesn’t have any vacuum hoses. Just two hoses for coolant to run through.

Please Log in or Create an account to join the conversation.

More
05 Apr 2019 07:10 #28436 by sgtdills
Replied by sgtdills on topic 1997 Honda Civic 1.6 surging idle up and down

MOROSO321 wrote: Ok thank you. I will. But this particular throttle body doesn’t have any vacuum hoses. Just two hoses for coolant to run through.

More than just on the throttle body, if you have a smoke machine you can use that for finding vacuum leaks.

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 17:02 #28448 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
hey guafa, check this out. when i placed my hand over the mouth of the throttle body, the surging stopped. it started idling ok. what is that telling me sir?

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 17:03 #28449 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
I sprayed soapy water like paul does it. but it showed no vacuum leaks yet.

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 17:10 #28450 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
I'm sorry. I need to make a correction here. I have 2 hoses in the back of the intake. One going to the brake booster and the other to the fuel regulator. Checked them, no change in idle speed.

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 17:20 #28451 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
no smoke machine, i wish. just a spray bottle with water. lol

Please Log in or Create an account to join the conversation.

More
05 Apr 2019 17:27 #28452 by guafa
Hi moroso.

That maybe is telling you that when you strangle air intake, A/F ratio is stichiometric or rich. If you check O2 voltage, you could see a rich output.

Do you have additional inputs from engine sensors?

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 17:34 - 05 Apr 2019 17:35 #28453 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
I have the map sensor and another sensor on the air duct. But I probably installed the wrong tb gasket. Because when I cover the mouth of the tb, the surging stops. So what is that telling me. Thank you.
Last edit: 05 Apr 2019 17:35 by MOROSO321.

Please Log in or Create an account to join the conversation.

More
05 Apr 2019 17:56 - 05 Apr 2019 17:59 #28454 by guafa
When you cover the t.b mouth, you change A/F ratio. For certain coolant temp.(ECT)/air temp (IAT)/ vacuum (MAP), ecu moves into a certain range of injection memory maps. According to some ecus i have studied, modifying sensor inputs you can reach those limits and ecu is not able anymore to keep stichiometric mixture.

It could be posible you are taking ecu to that limit and getting a rich mixture (you can check if so, by checking O2 sensor voltage)

Do you have any other engine inputs for you from a scannerdanner or any app? Those allow you for a better understanding of the issue you are facing
Last edit: 05 Apr 2019 17:59 by guafa.

Please Log in or Create an account to join the conversation.

  • Chad
  • Chad's Avatar
  • Offline
  • Moderator
  • Moderator
  • I am not a parts changer.
More
05 Apr 2019 18:07 #28455 by Chad

MOROSO321 wrote: Because when I cover the mouth of the tb, the surging stops. So what is that telling me.


I believe that is telling you that you definitely have a vacuum leak. A vacuum leak on a Speed Density Engine will cause a high idle. If the PCM has a rev limiter programmed into it, it will kill the injectors to prevent over revving. When the RPMs lower, the injectors kick back on and the cycle repeats. This is what causes the surging. If you can block the throttle body intake, with your hand, and the engine does not stall, you are receiving PLENTY of air for the engine to run from an UN-authorized source.

I suggest returning to the water bottle, while blocking the Thottle-body intake.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

Please Log in or Create an account to join the conversation.

More
05 Apr 2019 18:07 - 05 Apr 2019 19:24 #28456 by guafa
You should check for a vacuum leak in gaskets (tb to manifold, iac to tb, manifold to cylinder head) hoses and any other hole associated with intake manifold.
Last edit: 05 Apr 2019 19:24 by guafa.

Please Log in or Create an account to join the conversation.

More
05 Apr 2019 19:23 #28460 by guafa
When you cover tb mouth, besides constant rpm, do you notice a lower than normal idle speed?

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 21:08 #28461 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
Ok pole71, I will use water while covering the area. By the way, when I purchased a new throttle body gasket, it did not look like the original. I’m going to put the old one back and see what happens.

Please Log in or Create an account to join the conversation.

  • MOROSO321
  • Topic Author
  • Away
  • Premium Member
  • Premium Member
More
05 Apr 2019 21:16 #28462 by MOROSO321
Replied by MOROSO321 on topic 1997 Honda Civic 1.6 surging idle up and down
When I cover the opening, the surging stops and begins to idle normally.

Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to add attachements.
  • Not Allowed: to edit your message.
Time to create page: 0.757 seconds