Question about 1999 Isuzu Rodeo

7 Answers

Fast Idle Problem With 99 Isuzu Rodeo V6

Had a serious fast idle problem that got progressively worse. Was Idling at 3000rpm! Replaced Idle Control Valve. Idle back down to 750rpm. Turn off ignition. Restart. Idle back up to 1800rpm. OBDII say 0 trouble codes. Disconnected battery to clear computer. No change. Idle 1800rpm. Suspecting cheaply manufactured ICV, replaced ICV again. No change. Idle at 1800rpm. ICV receiving 12V. Pull ICV and adjust plunger. Start car. Idle 750rpm. Turn off car. Restart. Idle 1800rpm. Any suggestions?

Thanks.

Michael in San Diego

Posted by on

  • 1 more comment 
  • Old Suzer Jan 05, 2009

    I haven't started replacing parts yet, but my 1994 Rodeo 5 speed is acting about the same.



    Tom in Spring TX

  • wondermik Feb 25, 2009

    pa_guy12 got it right! I had a fast idle problem. Replaced the idle control valve twice, but the engine still idled at 1700 rpm. I sent the Rodeo to a friend that owns a junk yard and he had his mechanics work on it. They tried replacing the ECM twice! They also replaced the Air Flow Meter. Still, the Rodeo idled at 1700 rpm. I tried pa_guy12's solution of disconnecting the power steering pump pressure sensor and now the Rodeo idles at 750-800rpm!

    Now my new problem is that I can't buy the sensor. The Honda Passport uses a different sensor. Isuzu doesn't sell the sensor separate from the pump. I think this Rodeo will be donated to charity.

    Thanks again,
    pa_guy12

    MP


  • Miguel Ito
    Miguel Ito Aug 21, 2014

    I did it as well and wow... it worked after 4 months with the same trouble. Thanks

×

Ad

7 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Isuzu Master
  • 19,396 Answers

Hi.

If problem is only on startup and when idleing, then the problem is likely IAC system, also a vacuum leak will cause the same problem.

If problem is not only on startup and idle, but also when driving, then MAP sensor and EGR system must be checked.

Check also accelerator cable state and setting.


Fast Idle Problem With 99 Isuzu Rodeo V6 - 0f04b3c.jpg

The first thing to do is pulling out the OBDII fault codes stored in the ECM. This is done connecting a code reader to the ECM diagnostic port. The job can be done for a small fee at any local garage, and it is done for free at AutoZone.

The codes will help locating the problem.

About possible faults:

Problem is stalling when idling and during startup, but engine idling fast all the time. Problem not starting at times it is due to the fact that the wrong mixture is being sprayed, this is probably causing flooding and misfire. Since the CEL is on, one of the codes returned is probably misfire.

Check accelerator.

Check IAC system. This is composed by a valve and a solenoid that check and control amount of extra air air when the engine is idling. The IAC valve is located on top of the throttle body.

Check the vacuum system and try cranking with gas tank cap off. Vacuum system is tested using an hand tool gauge onvacuum lines while spraying card cleaner on the hoses (or heating them with a torch). If there is a leak, pressure will go up. A big leak will also do hissing noise, and will often result in a lean code when doing an OBD code scanning.

This kind of symptoms can also be caused by weak wiring to MAP/MAF sensor (MAP in this engine).

If the car also drives very rough and is revving up and down in a weird way, check the EGR valve.

As first thing I would do a code scanning. This car is OBDII. The scan can be done for free at the nearest Autozone, or for a small fee at any garage.

If you get any OBDII code from the scan, report it here, so that we can individuate the possible reason for the problem.

If you repute my solution helpful, then please take some times to accept the solution. Providing good repair tips requires time and skills, and your feedback is important for us.

Regards.

Ginko.

Posted on Oct 26, 2010

  • Miguel N Apr 26, 2013

    I have same problem and finally check engine light is on with code P0101 .99 Honda passport. what would my problem be?

×

Ad
  • Level 1:

    An expert who has achieved level 1.

    Governor:

    An expert whose answer got voted for 20 times.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 13 Answers

On the power steering pump is a wire....disconnect it and undo battery for 30 seconds.....see if this fixes it.....the swith in the power steering pump is supposed to bump idle by 200 on full turns....f it shorts it jacks up ilde every time u start truck.

Posted on Feb 15, 2009

  • Eric Stark
    Eric Stark Sep 13, 2015

    Wow! Amazing. Disconnected the power steering pump sensor: fast idle problem SOLVED!

×

Ad
  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

I have a 2000 Isuzu rodeo. Sometimes the car runs fine and others it is real rough and seems like it is going to die. It feels like a bad hesitation. It has an irradic idle, the reducced power light comes on sometimes. when you go around a corner it dies, sometimes. The car is a v6 . We have replaced the egr valve, the pcs sensor, plugs wires, starter, fuel pump, fuel filter,etc.

Posted on Feb 18, 2009

  • Brent Nonoffyours Apr 23, 2011

    I have the same exact problem. Did you finally fix it and if I may ask what was the problem.
    Thanks
    Brendt

×

  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

After changing my idle sensor, throtle position sensor and trying the ECM fuse disconect trick. My idle issues were not resolved. Before looking for an intake manifold leak I did the following, I disconnected the power steering preasure switch and my idle speed has returned to normal. I'm waiting to get a replacement switch for my PS pump. I'll post here with my results.

Posted on Jun 09, 2009

  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

I am by no means a mechanic but I just had a similar (possibly same) problem in a 2000 f-150. pretty sure mother in law has same problem. I think it could be the intake manifold gasket. I'm reading alot about spraying carb cleaner around manifold in order to find the leak. Vacuum problems will not show up on the vehicles computer, until they cause associated problems. Take it to autozone and ask them to read your vehicles code. Should be free. If no codes, almost definitely a vacuum problem. Seems to be a very common problem on vehicles in that year range.

Good Luck

Jay

Posted on Jul 30, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Isuzu Master
  • 20,706 Answers

Fast idle 101: USA CAR???? ill guess that....

first off you never said hot or cold engine?

if hot is it really hot? 180F (or 150) the engine will race if the engine thermostat is bad, and wrong temp. for sure.

if the engine never warms up it will race fast. so...

is it at 180F or more? on this V6 1999 (what size? V6?????)_

if that is ok, fails hot idle.

the next step is knowing the difference between the 2 EFI systems

(to a lay perso,n its MAF or MAP engine)

(makes all the difference that fact)

the MAP engine races for any air leaks (vacuum)

the MAF engines stalls or runs too slow as it goes LEAN.,

see>???????? (illegal air leaks means lean)

EFI controls , basics....

so which is it, ok i open my book. and look.

but wait there are THREE 6v engines. some are TWIN CAM (4 cams total) must i guess that too?

guess what the EFI is not the same on all 3 engines.....dang.

2.6-liter 4ZE1 engine?

3.2-liter 24-valve SOHC V6 (my guess)

3.2-liter V6 up to 194 hp (1996 up graded power)

or

The 6VE1W 3.5L DOHC 24V V6 was introduced in 1998 with 215 hp (160 kW) and used until 2004

so not saying the displacement , of this v6 is a pain.

ill GUESS its the 2.3L with single cam shaft each bank.

below is my guess on engine and not a guess on WHY.

so how does it race, this engine, in this car.

easy.

some cars have both sensors (map/maf) the map is used only at idle and low speeds, and then MAF takes over for more accurate, readings fast.

so we now know that the MAP sensor if it sees any air leaks the engine MUST race with full power, and not go lean.

so what is it.

as posted here the ISC is stuck open

or any vacuum line on car leaking for ANY reasons.

or any PLENUM leaks. for ANY reasons.

or the ISC is dead, because, the ECU sees the idle switch stuck open killing all idle controls. (read TPS errors)

you did the correct thing, unplugging the ISC

ISC ,= idle speed control valve 2 pins is modulated, more is motor drive ISC,. no matter what is there or it NAME.

this causes it to close.

and must not idle so low it stalls.

if NOT , they you just proved, you have vacuum leaks

(the isc can only close 100% and if the engine STILL races

the ECU can not by magic, close the valve more.)

CANT.

find the leak.

we pinch all hoses to find that first.

and lost more.... some leaks can be hard to find.

propane gas tricks

smoke machines

and more. lots more.



the parts store calls this part the IAC , idle air control

the name is not important.

it is a stepper motor drive, more than 2 pins tells you that.

or close.

getting it to close can be tricky.

one trick i do is to remove it. and pack clay in the port

sealing off all air to this port.

start car with 10% throttle.

then release the throttle , good engines stall now.

if it races it has AIR LEAKs big time, (vacuum leaks)

the engine can not run with no air, so.... there you go.

no air + lots of fuel is flooding.

some cars the ISC closes , unplugged. others not.

others just freeze where they were(steppers)

tricky huh?



on some engines, like this. the map is only there to test the EGR.

i do NOT have intimate knowledge of the PCM on this car.

nor have the very rare FSM books on it.

my guess, as the EGR has read back lines (it does)

the MAP is used at idle. for better calculations of air flow

the MAF work very poor at idle, such low air flow.

my guess based on many EFI systems, worked.

Posted on Sep 14, 2015

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 4 Answers

According to Mitchell OnDemand, turn the key on and off after IAC replacement then start. the PCM controld idle speed and is not adjustable.

Posted on Aug 14, 2008

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

I hooked my 95 Mazda mil up and says I need O2 sensor for bank 1 and 2 and also says I need engine speed circuit not sure wat to replace and wats really messd up please help


First is all always write down the codes you have present, it helps in closing down on the problem. I am assuming you have a 95 Mazda Milleinia

1. Start and run the engine and monitor the oxygen sensor signals and see if this sensor has bad readings still. Check for an open or shorted wire between the sensor and the Engine Control Module (ECM) if the signal is dropping out.

2. Listen for an exhaust leak in the area of the oxygen sensor, the leak could allow oxygen in to the exhaust and skew the sensor readings.

3. Inspect the ECM and ECM connector for signs of something that has been spilled on the ECM. Is the engine idling too high or too low then check this:-
1. Unplug the idle air control valve and turn the air bypass screw in to see if it will idle down. If it will idle down, adjust the idle speed to around 500 RPM's and then plug the idle air control valve back in.

2. If it still idles high, remove the air boot from the throttle body, block the air bypass ports with duct tape, hook the air boot back on and start it. This should make it not idle at all or just barley idle. If it does, the problem is in the idle air control valve.

3. If blocking the air ports doesn't cause it to idle down, the throttle plate must be sticking open. Clean the throttle plate really good and back the throttle stop screw off and then see if it idles down.

4. Verify the coolant level is not low and that coolant is circulating through the idle air control valve. Tech Tips: This idle air control valve is two valves in one. It is a fast idle thermo valve on one side and a duty cycle idle air control valve on the other.

Mar 30, 2015 | 1995 Mazda Millenia

1 Answer

Free seized engines


When the weather is warm, we rely on our car's cooling system to keep temperatures in the engine compartment under control, and keep us on the road. Your cooling system is a series of components that circulate coolant through the engine to absorb heat, then circulate air around the coolant to get it out. If any part of the system stops working, you're on the side of the road while your engine takes a steam bath.The best medicine is preventive. You should flush your radiator on schedule to keep the system clean and well flowing. Unfortunately we aren't always lucky, and things go wrong. Let us help you figure out why your car or truck is running hot or overheating.
Problem with 2000 BMW 528i idling problem when you start the car in the winter time. The care starts by idling aroun 1000rpm, which is normal for a cold engine start, but within 30 seconds it drops down to about 750rpm. Now the problem is that it fluctuates between 750rpm and 250rpm, almost shutting down, and sometimes does shutdown.
Solutions:
1. I would first try to clean out the Idle control valve...some people have seen a 30% increase on cold start idle, there are several links in the DIY section.

2. If the sounds like classic Vanos seal issues. I had the same problem with mine in the cold weather. It would go away after the car warmed up. Replaced the Vanos seals and the problem disappeared.
3. Make sure you get the correct replacement seals or you'll end up with the same problem down the road.

Jun 04, 2013 | 2000 BMW 528i

1 Answer

2.7 crd.grand cherokee 2002. Varying idling speed,dimmng lights


well it could be the idle control valve or vacuum leak check all vacuum lines for cracks and listen for air sound you may need to check PVC valve

Feb 08, 2010 | 2002 Jeep Grand Cherokee

1 Answer

2002 Neon - car idle rough with the A/C on. Have changed spark plugs, air filter, etc. and still runs rough. Took it to a shop and there are no fault codes. The problem only happens when the car sits in...


YOUR ENGINE IS IDLING LOW.MOST CARS WHEN YOU TURN ON AC THE PCM WILL INCREASE IDLE SPEED TO KEEP ENGINE FROM STALLING OUT.I WOULD HAVE THE IDLE SPEED CONTROL CHECK OUT AT THE DEALERSHIP.THEY WOULD HAVE TO ADJUST YOUR IDLE SPEED.SINCE MOST IS PCM CONTROLLED.

Sep 26, 2009 | 2002 Dodge Neon

1 Answer

Engine idling gone crazy


check for lose vacuum hoses or lose throttle hose make sure you air flow meter ducks are tite if you see everything ok then the idle speed control valve could be dirty with a little carburetor cleaner spray while engine is running open throttle and spray into throttle till you can see throttle is clean you may have to do this a few time hope this information is useful good luck

Jul 27, 2009 | 1995 Toyota Previa

1 Answer

Still Idling High!!


HI. i recommend inspecting the following areas for faults.

1. Air filter- this unit may be clogged or dirty.
2. PCV Valve- This device may be clogged. it is part of the emissions system.
3. Check the wire sets for damage.
4. Check each spark plug for damage.

Last. if your vehicle is equipped with a Idle stop solenoid, this may be the main issue. replace if found to be defective.

NOTE--(If the above inspection check out ok, this will confirm a more serious issue with the PCM(Power Control Module). This device controls the Idle and, it is not adjustable. you will need to replace this device if the above inspections are satisfactory.


Jul 11, 2009 | 2001 Hyundai Elantra

1 Answer

2000 mistubishi galant es idling rough seriously


Idling problems may be cause buy a number of issues.  You may check out the fast idle control valve and PCV if they would need cleaning.  You can check out the timing it may be advanced, that is why you feel that the car runs hard.

Jun 13, 2009 | 2000 Mitsubishi Galant

2 Answers

IDLING PROBLEMS ON 1992 ACCORD EX


Have the Idle Control Solenoid Valve cleaned up.

Or it might be defective. See steps below to check...
  1. Disconnect idle control solenoid valve electrical connector.
  2. Disconnect upper hose to solenoid valve from manifold and apply vacuum to hose. Valve should hold vacuum.
  3. Continue applying vacuum to hose and briefly energize valve by connecting battery positive terminal to the black/yellow wire terminal and negative battery terminal to the green/black wire terminal. Valve should not hold vacuum when energized.
  4. If idle control solenoid valve fails to perform as outlined, valve is defective.

Jun 03, 2009 | 1991 Honda Accord

2 Answers

1999 Ford Escort idle problems


PVC valve is not metering air correctly, it will appear ok shaking it but looses it ability to maintain proper position causing a medium to gross vacuum leak.

Sep 12, 2008 | 1998 Ford Escort

4 Answers

Ford focus 2000 1:8cc


check for a vaccum hose that broke or came off

Jun 25, 2008 | 2000 Ford Focus

Not finding what you are looking for?
1999 Isuzu Rodeo Logo

17,032 people viewed this question

Ask a Question

Usually answered in minutes!

Top Isuzu Experts

yadayada
yadayada

Level 3 Expert

79865 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

14411 Answers

Are you an Isuzu Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...