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Discussion Starter · #1 ·
anyone tell me how to adjust the idle
speed on a '98 -4.0L?
running about 200 rpm slow.
tried big hammer,no luck!

cheers eric


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2muchfun
1998 jeep cherokee 4.0l
keep the shiny side up!
 

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Superfly
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Originally posted by cherokee:
anyone tell me how to adjust the idle
speed on a '98 -4.0L?
running about 200 rpm slow.
tried big hammer,no luck!
Hmm...I've never had to do that before and am not even sure if there is an adjustment.

Is it always running 200 rpm slower or does it fluctuate? I'm wondering if one of your sensors is bad.


...lars



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Discussion Starter · #3 ·
yes lars, 200 rpm low all the time.
i checked for cable adjust,idle screw, nothing found.
oh well,i haven't seen craig for a while
might as well give jeep thrills some more
money.hahahahaha
probably a sensor like you said.
should drop in an old chevy 350,then i
would know how to deal with it
thanx lars

cheers; eric


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2muchfun
1998 jeep cherokee 4.0l
keep the shiny side up!
 

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Same thing here but for a 2.5L.....I looked for a screw to adjust it and found nothing.

Anyone??????


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Jason

1988 4Runner SAS Dana44/Dana60 with all the fixings (For Sale)

1994 Wrangler YJ (Stock, but will be rock worthy one day)
 

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AFAIK most EFI systems don't have an idle speed adjustment. If there was one, it would be electrical, not a screw or lever. I know on my EFI 5.0L, there isn't an idle speed adjustment. Period.

Lars is probably right - your problem is likely caused by a failure of a sensor or the idle bypass solenoid. Have you checked for any problem codes? I'm assuming there's a way to get the codes on your vehicle...

Chris

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Discussion Starter · #6 ·
on my unit ,codes are extracted with
the fancy OBDll scanner.retails for about
$265.00 canadian(or $125.00 an hour dealership time).
no code coming up at this time regarding
idle speed or malfunction.
drives/shifts ok,just an annoying rock at idle.(i'll tell everyone it's just a lumpy camshaft)hahahahaha
cheers; eric


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2muchfun
1998 jeep cherokee 4.0l
keep the shiny side up!
 

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Discussion Starter · #7 ·
saudi yj, your problem could be elevation/atmosphere pressure.
i know when i take my truck in high elevation
it idles a little eratically sometimes.
just talked to the dealership and they said
all idle adjustments are computer controlled.
no manual adjust available.
good luck, and stay safe over there.

cheers; eric


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2muchfun
1998 jeep cherokee 4.0l
keep the shiny side up!
 

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Superfly
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8,221 Posts
Originally posted by cherokee:
drives/shifts ok,just an annoying rock at idle.(i'll tell everyone it's just a lumpy camshaft)
My two guesses: crank shaft position sensor (CPS) or throttle position sensor (TPS). If you recently got the engine really wet (like if you cleaned the motor), odds are the TPS is toast.

...lars



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