High RPMS at start.

1998 Jeep cherokee Sport 4.0 inline 6 motor I replaced the Exhaust manifold and went though and torqued the bolts to the repair manual specs(May have skipped a couple on the sequence but all got torqued...When i start the engine it is at 4000 rpms with the throttle body valve closed. No vacuum lines are leaking or disconnected and I don't think the IAC would be the issue. allthough a while back I had to put a little rubber hose under the Coil spring that holds the throttle backs (the little set screw) to keep it from dieing at start.

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jackie

Jeep Expert 652 Answers
Posted on Nov 26, 2013

jackie

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The gasket on the intake may have got pinched or intake not cleaned on mating surface

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Anonymous

44 Answers
Posted on Oct 19, 2008

SOURCE: high idle 1997 Madza 626 4 cylinder auto transamission

The PCM controls idle speed to ensure good driveability. The PCM will only attempt to maintain the desired idle speed when it “knows” the throttle is closed. A throttle switch or the TPS input is used to determine when the throttle is in the idle position. Motors and solenoids are used by most PCM’s to control idle speed. Many PCM’s are programmed to attempt to control the idle speed by adjusting spark timing and then by controlling the idle speed actuator. Some computers of the early 80's did not control idle speed.

Anonymous

1 Answer
Posted on Nov 14, 2008

SOURCE: 88 Nissan z24i backfires through throttle body and loses power when in gear

Check your intake and exhaust modules. I have a 1987 D21 and had the same problem (if I understand your post). I replaced the modules located behind the driver side headlights and it fixed the problem. Good luck! I hope this helps.

Anonymous

25 Answers
Posted on Mar 17, 2009

SOURCE: 87 samurai bolt torque specs for engine

The haynes book is not recommended since there are numerous mistakes and they still will not update. One of the biggest is the firing order.

The factory service manual is the only way to go.

Head bolts - 46 - 50.5 lbs (there is an order sequence for the bolts)

Intake & exhuast manifolds- 13.5 - 20 lbs

Flywheel - 41.5 - 47 lbs

Clutch cover - 13.5 - 20 lbs

Marvin

85242 Answers
Posted on May 22, 2009

SOURCE: PCV valve? IAC valve? Sparkplug wire? Throttle body? Vacuum hose?

the most common causes are plug wire, plug, vacuum leak at intake, fuel injector failure and last no/low cylinder compressio.

Anonymous

326 Answers
Posted on Apr 11, 2010

SOURCE: 1998 Monte Carlo (Z34) stalls when braking/RPMs rise then drop

ON THE SIDE OF THROTTLE BODY IS THE IDLE AIR CONTROL MOTOR GENERALLY HELD IN PLACE WITH TWO TORK SCREWS REMOVE SCREWS AND SLIDE OUT OF THROTTLE BODY THERE IS A PLUNGER ON END OF IAC MOTOR CLEAN IT GOOD AND THE SEAT UP IN THE THROTTLE BODY AND RE-INSTALL THIS MAY HELP TO ALLEVIATE SOME OF THE FLUCUATION IN RPM,S CLEANING CAN BE DONE WITH CARB SPRAY AND A OLD TOOTHBRUSH

Testimonial: "The info on my idle speed control was correct, it was broke beyond repair. Replacing it fixed it for a whole 20 minutes. After that I changed the EGR Valve and the Mass Air Flow Senser. Everything runs fine now -no stalling."

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According to the service literature I read, the 2003 Montero Sport with the 3.0 or 3.5 L engine does not have O2 sensors listed even in the maintenance schedule. The 2.4 L engine has it on the exhaust manifold though.
---
However, the following lists the par, though for before or after the catalytic converter:

http://www.partstrain.com/store/index.php?VN=4294967180+4294966587+4294964143+&Nr=AND(universal:0)&N=0&Ntt=Oxygen%20Sensor

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I think that $250 to $300 is reasonable if the Oxygen sensors are stuck in there with rust and the threads are preserved by the technician. Oxygen Sensor replacement can be tricky.
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Good luck on this repair.

Exhaust Manifold

REMOVAL & INSTALLATION

2.4L Engine

Remove or disconnect the following:
- Negative battery cable
CAUTION
Wait at least 90 seconds after the negative
battery cable is disconnected to prevent possible deployment of the air bag.
Heat cowl from the exhaust manifold
Aspirator valve assembly, if equipped
Oil dipstick and guide
Oxygen (O2S) sensor connector and ground cable, if equipped
Exhaust pipe from the manifold
Exhaust manifold and gasket from the engine
To install:
Install or connect the following:
- Exhaust manifold. Torque the M8 mounting nuts to 22 ft. lbs. (29 Nm) and the
  M10 mounting bolts 36 ft. lbs. (49 Nm). starting from the middle and working
  outward.
- O2S sensor connector and ground cable, if equipped
- Exhaust pipe to the manifold. Torque the nuts to 35ft. (49 Nm).
- Aspirator valve assembly, if removed
- Heat cowl to the exhaust manifold. Torque the bolts to 117 inch lbs. (13
  Nm).
- Negative battery cable
Start the engine and check for exhaust leaks.

3.0L and 3.5L Engines

Remove or disconnect the following:
- Negative battery cable
- Exhaust pipe from the exhaust manifolds
- Oil dipstick, guide and O-ring
- Heat shields
- Exhaust manifolds
Clean the gasket mounting surfaces. Inspect the manifolds for cracks,
flatness and/or damage.
To install:
Install or connect the following:
- New gasket and exhaust manifold. Torque the nuts to 33 ft. lbs. (44 Nm) on
  3.0L engines and 22 ft. lbs. (29 Nm) on 3.5L engines.
- Heat shield, Torque the bolts to 10 ft. lbs. (14 Nm).
- Exhaust pipe to the exhaust manifolds. Torque the nuts to 35ft. (49 Nm).
- Oil dipstick, guide and new O-ring
- Negative battery cable
Start the engine and check for exhaust leaks.

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Oct 07, 2010 • 2003 Mitsubishi Montero Sport

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3answers

How to properly relieve the fuel system on a 98 jeep cherokee?

On the fuel rail there is a small cap that you will remove, inside is a schradervalve(like on a tire stem)depress it with a small screwdriver to relieve pressure FUEL WILL SPRAY,NO SMOKING,USE CAUTION, be in a well ventialated area. NO OPEN FLAMES.

Modern head gaskets do not require additional sealer or retorqueing. Follow gasket maker recomendations. and torque as recomended by Jeep.

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Oct 10, 2009 • 1998 Jeep Cherokee

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2answers

What is the torque specs for a 1998 jeep Cherokee classic straight 6 4.0 liter? I am replacing the head gasket and need to find the lbs of torque. Thank you for any advice, pictures, etc.

Torque sequence ------------------ front | 12 8 4 1 5 9 13 | of | | engine | 11 7 3 2 6 10 14 | ------------------ Final torque must be reached in 3 equal steps Step 1: torque all bolts (except bolt 11) to 110 Ft/Lbs Step 2: torque bolt 11 to 100 Ft/Lbs Recheck final torque in sequence.

Disconnect the negative battery cable.
Drain the cooling system.
Disconnect the hoses at the thermostat housing.
Properly relieve the fuel system pressure.
Remove the cylinder head cover.
Loosen the rocker arms.
Remove the pushrods.

The valvetrain components must be replaced in their original positions.

Remove the intake and exhaust manifold from the cylinder head.
Disconnect the spark plug wires and remove the spark plugs.
Disconnect the temperature sending unit wire, ignition coil and bracket assembly from the engine.
Remove the accessory drive belt(s).
Unbolt and set aside the power steering pump and bracket. Do not disconnect the hoses.
Remove the intake and exhaust manifold assembly.
If equipped with A/C, perform the following:
1. Remove the compressor and position it aside with the lines attached.
2. Remove the compressor bracket bolts from the cylinder head.
3. Loosen the through bolt at the bottom of the bracket.
Remove the alternator.
Remove the cylinder head bolts, the cylinder head and gasket from the block.

Bolt No. 14 cannot be removed until the head is moved forward. Pull the bolt out as far as it will go and suspend in place by wrapping with tape.

Discard the gasket. Thoroughly clean the head-to-block mating surface.
Clean and inspect the cylinder head thoroughly. Refer to the engine reconditioning portion outlined later in this section.

To install:

Coat a new head gasket with suitable sealing compound and place it on the block. Most replacement gaskets will have the word TOP stamped on them.

Apply sealing compound only to the cylinder head gasket. Do not allow sealing compound to enter the cylinder bore.

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Oct 08, 2009 • 1998 Jeep Cherokee

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2answers

What is the tension on cylinder head bolts for a jeep grand cherokee 307935 4 litre, 6 cylinder, 1999, petrol motor.

Coat threads of left hand front bolt with sealant: 1st - step; - 22 ft./lbs. 2nd - step; - 45 ft./lbs. 3rd - step, all bolts except L.H. front bolt; - 110 ft./lbs. 4th - step, L.H. front bolt; - 100 ft./lbs.

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Sep 05, 2009 • 1999 Jeep Grand Cherokee

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1answer

92 Jeep Cherokee losing power up hills / EVAP failure

Running out of power going up a hill is generally the fuel pump. Now days a plugged catalytic converter will do it also. The fuel evaporation test could be a bad gas cap or evaporation canister or hose somewhere. The exhaust manifold is a jeep thing, expansion and contraction, hot cold over and over. Have it welded or replaced.

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Jun 06, 2009 • 1992 Jeep Cherokee Sport

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1991 jeep cherokee sport 4.0

For your 1991 Jeep Cherokee 2WD 4.0L MFI :
Foot pounds (Final torque)

Note:
Torque sequence ------------------
front | 12 8 4 1 5 9 13 |
of | |
engine | 11 7 3 2 6 10 14 |
------------------
Final torque must be reached in 3 equal steps
Step 1: torque all bolts (except bolt 11)
to 110 Ft/Lbs
Step 2: torque bolt 11 to 100 Ft/Lbs
Recheck final torque in sequence

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Sep 30, 2008 • 1991 Jeep Cherokee Briarwood

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Where are the oxygen sencors on my 1998 jeep cherokee sport 4.0

1998 Jeep Cherokee

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