Question about 2002 Buick Century

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Ive changed the mass air flow sensor but it idles rough

I made sure spark plugs and wires are good but it still idles rough what could be the problem

Posted by Anonymous on

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5 Related Answers

Anonymous

  • 321 Answers

SOURCE: buick lesabre nightmare 2

  • The PCM doesn't even see the O2 sensor until engine temp has reached operating temp,the vehicle goes from open loop when cold,to closed loop when warm,where the PCM uses the O2 sensor to measure the rich/lean of the exhaust content,and from that,adjust fuel richness to achieve 14.7 to 1 air/fuel ratio.So when cold,the O2 sensor is out of the picture anyways.When unplugging sensors,it can be deceitful.The PCM has a program whereas,if a critical sensor (such as the mass air flow) is somehow damaged and out of the picture,the PCM will substitue a generic value that will allow the engine to stay running.So,by unplugging the MAF,it did try to run on it's own better than plugged in,there's the problem area.The vehicle is running better with the MAF unplugged,because the MAF is likely bad,and the PCM is substituting it's generic value when it IS unplugged.Something to recheckThe PROM update is a newer program for the PCM,and likely won't fix it unless the PCM is bad.I would try a good used PCM as a last or later resort,because i have seen my fair share of defective PCM's too.I have taken some PCM's apart,and found capacitors that had gone bad and leaked all over the circuit board,mostly Honda and Mitsubishi and Chrysler though.Good luck,keep me posted.

Posted on Aug 01, 2008

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Anonymous

  • 19 Answers

SOURCE: 1997 buick lasabre custom high idle, transmission, stalling

had same problem i would check the Idel Air Valve and also check all of your vaccum hose lines makeing sure there are no cracks or splits in rubber connectors if there is repair immediatelt because over time they start to dammage the internal parts fo the engine and if youve replace tps mass air etc. sounds like a vaccum hose problem

Posted on Feb 10, 2009

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Richard Scordino

  • 6982 Answers

SOURCE: Mass Air Flow Sensor - 92 Buick Century

Remove it and clean with some carb cleaner and a Q tip. Be careful with it so you don't do any damage. 9 of 10 times this will get you running again! Since signal from there is variable low voltage, you cant really bypass it!

Posted on Feb 16, 2009

SOURCE: Where is the Mass Air Flow Sensor?

It is inline with the air intake .They are typically held in the tubing with hose clamps and a 2 or 3 wire connection. Make sure you check for direction of air flow.

Posted on Apr 21, 2010

Anonymous

  • 196 Answers

SOURCE: 97 buick lesabre 3.8 Idles rough and stalls out.

ignition system not operating properly ,or intake air leak ...crank engine get a can of staring fluid spray around the intake if the motor idles up you got a leak hope this helps

Posted on May 08, 2010

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1 Answer

2000 kia sportage 4x4 never seen anything like it. changed plugs both coils and both plug wires all bad and still starting rough press on idle feels like not getting enough gas high idle sensor off.


-Not always the plugs and the coil case this. This can be cause by bad injector. Dirty mass air flow sensor.
-First Clean mass air flow sensor. If it's still do the same thing
then check the resistance of every injector. If it's not within its specification then replace it.

Good Luck

Mai

Jan 25, 2017 | Kia Cars & Trucks

1 Answer

Rough idle only when stopped


Vacuum leak , mass air flow sensor dirty , dirty throttle plate . YouTube videos will show you how to diagnose this problem . How to Clean an Electronic Throttle Body Safely How To Clean Mass Air Flow Sensor Properly Misfire caused by vacuum leak

Good luck an good hunting ! an have fun !!!!


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Engen problem and missing


Sir, your question is not very clear, but I will still try to post a solution here. Engine missing could be due to any problem in fuel system, ignition system, engine or ECM as well.

LOW ENGINE IDLE SPEED (Poor idling):
-Throttle body (do the cleaning and idle speed learning)
-A /C signal circuit
-Fuel pump control circuit
-Fuel pump
-Intake system
-P C V valve (clogged or open) and hose

ROUGH IDLING:
-Cylinder Compression
-Ignition system (Igniters, spark plugs, wiring harness)
-Spark plug fouled, gap too wide or too short. (1.00-1.1 mm)
-Fuel injector circuit
-E C M power source circuit
-Fuel pump control circuit
-Fuel pump (required pressure 44 psi - 49 psi)
-Throttle body (cleaning)
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Heated oxygen s ens or
-Mass air flow meter
-Idle hunting
-Throttle body
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Mass air flow meter

HESITATION/ POOR ACCELERATION:
-Fuel pump control circuit
-Fuel pump
-Spark plug
-Ignition system
-Fuel injector circuit
-E C M power source circuit
-Mass air flow meter
-Throttle body (do cleaning)
-Intake system
-Valve timing
-Cylinder Compression


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1 Answer

2.2 litre 1995 gmc sonoma idles rough no trouble code. found hole i brake booster vaccum line fixed that. replaced and changed fuel filter, idle air control valve, got spark at coil packs, put new spark...


Three things you should check using a good code checker which can read sensor outputs - the throttle position sensor (TPS), the mass air flow sensor (MAF) and the EGR valve. While you are at it, replace the PCV valve.

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Mass air flow sensor, is the air box and all vaccuum hoses tight? make 100 percent sure that wires and plugs are good. Dont deviate from the motorcraft plugs and good wires-ACDelco or similar. Possibly coil.

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Engine idles rough at stops and in park is it idiling sensor or something


This could be a lot of things. There is no 'sensor' but there is an IAC (idle control valve) that lets air into the engine when you aren't using the throttle. But, when this part goes bad your engine usually will idle really high or not at all. You could have a slight misfire or broken/worn engine/transmission mount. A tune-up could eliminate maintainence caused problems. You should replace the air filter, fuel filter, spark plugs, spark plug wires, PCV valve, and run a good injector cleaner through like Chevron Techron or Valvoline Synpower. If this doesn't solve your rough idle, then you likely have a broken mount somewhere.

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Runs ruff changed mass air flow plug wires plugs


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I have a 99 kia sephia. I've changed the spark plugs and wires my coil wire, alternator, and battery. It's gone from not even turning over to starting on it's own. I did the troubleshooting guide in my...


make sure that your clean air intake is all hooked up correctly this is a common problem because when the mass air flow sensor detects too much or too little air it will try to die or idle rocky also if it is correct look to make sure the air filter is clean if not then replace it.

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I have a 1999 oldsmobile intrigue that is misting a lot. It idels rough, and runs rough. I can still take off it is a little slow, but I can still go pretty fast, but it still mist at the high speeds...


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