1997 Isuzu Hombre Rough Idiling

Tiny
HANKS782
  • 1997 ISUZU HOMBRE

Engine Performance problem
1997 Isuzu Hombre 4 cyl Manual 198000 miles

Today I noticed my truck began to idle roughly. The engine runs roughly only at idle. The engine does not seem rough while I drive. When at idle it feels like the whole truck is rocking.
We are thinking there is a valve problem. Are we correct? If so. Would we need to have them changed? Or adjusted?

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Friday, August 7th, 2009 AT 8:00 PM

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Tiny
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Hello,

Usually with a valve problem you will hear them tapping.

I would first check for Vacuum Leaks.

Also is the engine light on? If so go by your local parts store and have them pull codes. Could narrow down cause of rough idle.

Post codes here.

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Friday, August 7th, 2009 AT 8:28 PM
Tiny
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It came up with 3 problems:

Definition
BBABS rough road system fault
Probable cause
BB1.-ABS system fault - check other systems for
BBtrouble codes

Definition
BBCylinder misfire detected number 2
Explanation
BBThe powertrain control module monitors the
BBcrankshaft speed and has detected a misfire
BBcondition
Problem cause
BB.- Ignition system fault-spark plugs, ignition
BBwires, coil
BB.-Vacuum leak
BB.-Injector fault
BB.- High or low fuel pressure

Definition
BBFuel trim bank one condition
Explanation

BBThe Power train control module uses the oxygen
BBsensor to calculate the Air/Fuel ratio of the
BBengine. The computer has recognized a rich or lean
BBcondition on one engine bank only.
Probabe Cause
BB.- If one and two codes set together suspect fuel BBpressure or MAF (mass air flow) sensor
BB.- Oxygen sensor defective
BB.- Ignition misfire repair
BB.- Fuel injector problem

Any insight into all this would be welcomed and greatly appreciated.
Thank You!

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Wednesday, August 12th, 2009 AT 10:30 PM
Tiny
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Ok, when was your last tune up? If been a while I would do tune up and see what happens. Change the Plugs and Wires.

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Thursday, August 13th, 2009 AT 9:54 PM
Tiny
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The last tune up was 2 weeks ago. New spark plugs, air filter, fuel filter, & pcv valve. The wires were changes the tune before. Anything else we could have done?

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Friday, August 14th, 2009 AT 12:47 PM
Tiny
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Ok, other possibilities are.

Bad or Weak Fuel Pressure Regulator and/or Fuel Pump.

Vacuum Leak

Bad or Leaking Injector(s)

Bad or Weak Spark - Meaning possibility of one of the towers on the coil pack could be bad.

Also do you have the Number Codes? Should look like this P****. The **** represent the Numbers like P0301.

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Friday, August 14th, 2009 AT 5:06 PM
Tiny
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The guy who did it did not give us actual codes. What I sent you was all he gave me.

I have had 2 people since asking the question tell us it sounds like a vacuum leak. My dad being one of the two. He used to do a lot of mechanical work. He said to check for a vacuum leak and that it could be a bad sensor in the fuel system.

The hubby is going to start with checking for a vacuum leak and go down the list from there if it does not work. I wish I had the codes to give you.

Thank You for your help.

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Friday, August 14th, 2009 AT 11:56 PM
Tiny
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Ok, you can get the codes by going by your local auto parts store. The will pull them for you, and most do it free.

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Sunday, August 16th, 2009 AT 9:22 PM
Tiny
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We went to the only auto part store that hooks up the tester and that is all he gave us.
Does he have to redo it so I can get codes?

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Monday, August 17th, 2009 AT 11:04 AM
Tiny
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Did they charge you for pulling codes? If not call them and ask if they can give you the code itself and not just the defs. If they can, and they should be able to, you'll probably need to have them pull the codes again.

I ask for the number codes because it is usually easier to figure a problem with a simple easy to understand code def.

For example this def -

BBCylinder misfire detected number 2

Could be P0302 - cylinder 2 misfire

Which as you can see is very similar to the def they gave you.

The other defs they gave you could just be a symptom caused by another code. It is easier for me to dianose with the number codes.

Also what has been checked so far with the list I suggested.

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Monday, August 17th, 2009 AT 6:29 PM
Tiny
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We went by today to get the actual codes.
He gave us these codes
P0172
P0302
P01380

Hubby is having a hard time finding the vacuum hose. He has never had to change one before.
We do not have a covered area and it rains everyday here lately so it is hard to find a chance to work on the truck.
Also he is leaving in the morning for 2 weeks for work so it will be that long before he gets to work on the truck.

If you can tell us exactly what those codes mean so we will know exactly what to fix that would be great!

Thank You.

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Friday, August 21st, 2009 AT 12:10 AM
Tiny
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Ok, here are the code defs.

P0172 System too Rich (Bank 1)

P0302 Cylinder 2 Misfire Detected

P1380 EBTCM DTC Detected-Rough Data Unusable.

So, with the #2 cylinder misfiring I would suggest swapping one plug wire for another and if the misfire moves to the cylinder you swapped with then I would say you have a bad wire and would change wires again. You could also check with the parts store if you have the receipt and see if they have a warrantee.

And if that wire is bad that can be causing the code P0172.

I will need to check on the code P1380 because that reffers to the Transmission Control Module and they are usually only used on Automatic trannies.

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Friday, August 21st, 2009 AT 10:12 PM
Tiny
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Ok, is the truck 4 wheel drive? If so I believe it is referring to the Transfer Case Control Module. Which would indicate that it is possibly bad.

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Friday, August 21st, 2009 AT 10:15 PM
Tiny
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Hubby said the truck is a rear wheel drive not a 4 wheel drive.

Also he wanted to know if the type of plugs he used would make a difference. This time instead of the regular Bosch Platinum he used the Bosch Platimnum Plus 4 (the ones with the 4 prongs) He was told they worked better but after he changed to them we are having these issues.

He said when he gets home he will go ahead and just change the wires and see if it runs better or normally. Wires are not too expensive.

I told him all this trouble means he needs to get me a nice little automatic vehicle. I am getting sick of his manual. HA HA

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Friday, August 21st, 2009 AT 10:48 PM
Tiny
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Well, Honestly I don't like or recommend them. I haven't had any good experiences with them.

And yes it is possible the plugs are the cause. I always recommend using OE (Original Equipment) or an OE Equivalent Design.

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Friday, August 21st, 2009 AT 11:08 PM
Tiny
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Ok Since the last problem with the truck we have changed all the spark plugs and such. There is a new fuel pump.
Ok the fuel is burning too rich. I am thinking we need to change the oxygen sensor and really hoping it is not the injectors. I had remembered one of the codes was P0172 (System Adaptive fuel too rich). My husband has been driving the truck and not me. Since we started having problems I stopped driving it. He came home 3 days ago complaining about the truck not wanting to go after stopping.
He said he has to pump the gas or push the pedal to the floor to get it to go from a stop. Once it is running it is fine. I called a local repair shop to get a price on cleaning the injectors and I never did get a price. All I received was down talk. I guess he assumed since I was a woman I was stupid. Lets just say I am not going to him to fix anything.
I want to know if we should change the oxygen sensor since the fuel is rich. I do not want the truck to get worse. We would like to get it all done this Friday when we get paid. Also if it is the Oxygen Sensor. How many are there? I know it is located at the catalytic converter. Are there two? I believe it calls for the unheated ones. The engine is a 2.2 L SFI 4 cyl. Please help! I am trying to keep this truck alive for at least one more year. Lol

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Monday, January 4th, 2010 AT 6:19 PM
Tiny
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/Ok, there are at least 2 O2 Sensors one in the Exhaust Manifold at the engine then one by the Cat some models also have one behind or after the cat.

As far as changing it and fixing the problem it may or may not, here some info on running rich.

Because the sensor reacts to oxygen in the exhaust and not fuel, any engine problem that allows unburned air to pass through the cylinders will also trick an O2 sensor into reading lean. A misfiring spark plug or a leaky exhaust valve - even a leak in the exhaust manifold gasket - may allow enough air into the exhaust to screw up the sensor readings. It won't damage the sensor, but it will create a rich running condition that hurts emissions and fuel economy.

So, I would also check for vacuum leaks, and if the misfire is still present in the #2 cylinder then need to find cause.

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Monday, January 4th, 2010 AT 8:16 PM
Tiny
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Would any of this be what is causing the acceleration problem. We did find one vacuum leak and changed that line. We have not found any others. Since we noticed this problem we have noticed a considerable drop in gas mileage too. We used to get 400 miles to a take and not we seem to have lost at least 100 miles per tank.

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Monday, January 4th, 2010 AT 10:01 PM
Tiny
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The biggest one that would cause the lack of acceleration is the misfire. If it is still there then need to find cause.

So, if still have misfire need to check Injector and Injector Harness.

Here is more info on the P0302 code - Cylinder #2 Misfire.

A code P0302 may mean that one or more of the following has happened:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer
Possible SolutionsIf there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.E. Spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.K.A. Coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Here is more info on the P0172 code - Rich condition Bank 1.

A code P0172 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak.
There could be a fuel pressure or delivery problem
Possible SolutionsPossible solutions include:

Inspect all vacuum and PCV hoses, replace if necessary
Cleanthe MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect fuel lines for cracks, leaks, or pinches
Check the fuel pressure at the fuel rail
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)

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Thursday, January 7th, 2010 AT 7:14 AM
Tiny
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Ok, well think I have found the problem. Here is the Isuzu code def.

P1380 ABS Rough Road Data Unusable

And from what I have read and found on this code the most likely cause is your PCM. It describes pretty much all the problems you have describe.

I will email you the info I found.

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Thursday, January 7th, 2010 AT 8:29 AM

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