1997 jeep idle problems and tapping from a part under the hood

Idle adjustment procedure - Ford Explorer and Ranger Forums ...

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Mar 25, 2015 - 19 posts - ‎11 authors Idle adjustment procedure Under the Hood. ... Below are the stock idle speeds (RPM) for my 2000 SOHC V6 with strategy CDE4. ..... when you apply the throttle or it could be too much base timing causing a huge misfire. High Idle Blues 1994 4.0
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which engine, there are many opted engine, name one.
did you say the engine lacks power? under what conditions.
Parked
moving.
hills,
wideopen throttle weak?
what?

btw : no idle works right if the engine runs bad.
lean fuel the ISC cant control idle ,
same for misifire.
idle is the last thing to work right in EFI.

is engine misfiring, and if so did it before the tune up or after./?

double posted
post RPM in both modes,
it must be the same
the ISC idle controls system controls idle at all times.
post RPM. 800 is normal. the exact valve is in the FSM
and posted under the hood in USA.
no country stated in 4000s posts so.... well, gee....
here, open the hood, look up, see EPA vacuum map
that is also the the engine size and type , and most state the normal
hot RPM clearly there, and is in the FSM.

here is the acid test. hot.
in park hot, rpm 800 if not the ISC fuction is dead
"idle speed controls"
good? yes.
then select drive. if RPM drops ISC is malfing.
now back to park. (all this is in the FSM to read)
now 800 hot. you turn on all heavy electrical loads
the rpm does not drop. Head lights + heater fan, and defrost.
all these test he ISC, if it fails its bad.
what does bad mean, that means its out of control
and you do further testing to find the reasons.

vast reasons.
Ill name 3:
intake air leaks. aka vacuum leaks.
ISC valve dirty , clean it.
throttle cables , misadjusted.
cold start air valve stuck open hot.

Sounds like a serious vacuum leak to me. Can you hear any air rushing under the hood when it's idling? Wiggle all your hoses around while its running and listen for a hiss. If it was a sensor his scanner should have picked it up, and if the fuel pump was no good, it wouldn't run at all. Aim a timing light at the crank mark. If it's jumping back and forth, your timing chain has jumped.

Start checking All vacuum lines under hood,on a 75 good chance 1 or more are cracked and leaking!

i had a problem like this with my jeep. ended up being a bad ground strap. try replacing or cleaning them up.

look under the hood and try switching the auto shutoff fuse.

most fuel injected car dont have a adjustible idle, most likely you have an intake leak
listen under hood for a sucking noise

Most of the time an engine is supposed to idle at 5-600 RPM in Driveif it's not you can up the idle. But you also may have a vaccume leak.

I have the same Jeep and same problem. The engine was running rough. The Jeep dealer fixed a vacum problem in the manifold and they then decarbonized and cleaned the fuel injectors. After these repairs the idle problem began, it would spike to 2000 rpm while sitting at idle, sometimes it would slowly come down, sometimes I would have to tap the accelerator. I took it back in and they then replaced the throttle motor and reprogrammed the PCM (Power Control Module?) Still same problem. Now they suspect a another vacuum leak and I am taking it back in on Tuesday, will let you know what happens, $ 1,300 so far.