Jeep Header swap issues - Page 2 - JeepForum.com
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post #16 of 30 Old 03-06-2013, 06:07 PM
Que89YJ
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Still having high rpm?

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post #17 of 30 Old 03-06-2013, 06:22 PM Thread Starter
dpr333
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Yea, crazy high. It starts around 1800 and steadily rises without me touching anything. It will keep going until I get worried and kill the motor
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post #18 of 30 Old 03-06-2013, 06:35 PM
Que89YJ
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It sounds like the iac.
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post #19 of 30 Old 03-06-2013, 07:25 PM
95yj0645
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I would almost lay $5 down that you have something pinched under the intake manifold, or the alignment dowels are stuck causing a rather large vacuum leak. I had the EXACT same issue when I did my header. Ended up I was torquing down on a crooked dowel and it was sucking air past the throttle body causing my idle to sky rocket. I mean you didnt do anything except put a header and bigger injectors correct? the injectors I would imagine would make it run rougher until you match the extra fuel with more air. my $0.02.......
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post #20 of 30 Old 03-11-2013, 11:05 AM
Que89YJ
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Any updates?
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post #21 of 30 Old 03-11-2013, 01:15 PM Thread Starter
dpr333
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Nothing yet. Had a rough weekend.
I am going to completely take the intake manifold off tomorrow and start fresh. It's gotta be a vacuum leak do to the fact that I didn't touch anything beside swap the headers and Injectors. I put the old injectors back in with no fix
95yj- are you referring to the alignment dowels coming out of the block,?
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post #22 of 30 Old 03-12-2013, 10:06 PM
Fuzzy_Wuzzy
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Yeah I see it's posted but my bet is that it is not sitting against the head right and pulling extra air in.
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post #23 of 30 Old 03-12-2013, 11:07 PM
rambo3489
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Wouldn't a leak on the intake manifold cause a lean mixture causing the engine to die. Not rev higher? This happened to me on my 4.0 head swap. The intake manifold was hitting the headers in two places not allowing a proper seat. Thus sucking in air like crazy. It would not idle unless I kept feeding it the gas.

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post #24 of 30 Old 03-13-2013, 07:59 AM
Que89YJ
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No it's a vacuum leak so the ECU thanks its idling too low and runs a higher rpm.
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post #25 of 30 Old 03-13-2013, 12:36 PM
Siva283
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If its the intake that is leaking the ECM would see a lean condition and add more fuel since it cant control the air getting in there. Correct me if I am wrong someone. That would mess vacuum up also and cause it to be low as far as the ECM is concerned. Break out the carb cleaner and spray it around the mating surfaces and see what happens.

1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

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I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim
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. It started with a $200 axle, and a few thousand dollars later I was done :)
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diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

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this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.
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post #26 of 30 Old 03-13-2013, 05:57 PM
Que89YJ
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Yes. but the map sensor is the big issue. It sets advance and would think the idle is low. The O2 is looking at the air fuel mix.
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post #27 of 30 Old 03-13-2013, 06:25 PM
Siva283
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He said he hooked map back up with no change.

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1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

Quote:
Originally Posted by Magnum View Post
I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim
Quote:
Originally Posted by ldso View Post
. It started with a $200 axle, and a few thousand dollars later I was done :)
Quote:
Originally Posted by Luuca View Post
diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...
Quote:
Originally Posted by Overhead View Post
this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.
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post #28 of 30 Old 03-13-2013, 06:46 PM
Que89YJ
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Yes. I think it's a vacuum leak throwing off the map. Make sure to disconnect the battery to clear the ecu.
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post #29 of 30 Old 03-13-2013, 06:48 PM
Siva283
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Quote:
Originally Posted by Que89YJ View Post
Yes. I think it's a vacuum leak throwing off the map. Make sure to disconnect the battery to clear the ecu.
Gotcha I miss understood what you were saying.

Sent from my Galaxy S3 using JeepForum

1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

Quote:
Originally Posted by Magnum View Post
I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim
Quote:
Originally Posted by ldso View Post
. It started with a $200 axle, and a few thousand dollars later I was done :)
Quote:
Originally Posted by Luuca View Post
diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...
Quote:
Originally Posted by Overhead View Post
this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.
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post #30 of 30 Old 07-12-2013, 11:42 AM
dhyasyn
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I had the same problem when I swap my header out. just torque the intake manifold down tighter, its just a leak sucking in air.
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