Rough idle problem and can't find solution

Tiny
CARDETAILER18
  • 1996 FORD RANGER
  • 197,100 MILES

I have a 96 Ford Ranger 2.3l 5 speed that has been having a rough idle problem for the past 2 or 3 weeks. My truck was running fine and then I had the CEL come on and the code was P0401 or EGR Flow is insufficient. I proceeded to change the EGR Valve and when I did this and started up my truck it was idling rough, so I put the old EGR back on and it didn't fix the rough idle problem. Since then I have changed the EGR Valve, EGR Vacuum Solenoid, EGR Sensor, IAC Valve, Air Filter, Fuel Filter, Upper Oxygen Sensor, Spark Plugs and Wires, and I have cleaned the MAF Sensor and the Intake Manifold and Throttle Body. When I took off the Intake Manifold the hole that goes to the EGR valve was completely clogged and since I cleaned it the CEL has not come back on. I have also had 2 instances of the CEL coming on and it being a Cylinder #2 misfire. Ever since I cleaned the Intake Manifold a week ago I have not had any CEL's. My truck is still idling rough. I took it to Ford and had them do a diagnostic on it and they told me that it wasn't misfiring and that it didn't have any codes stored in the computer. They also did a compression test, which said that cylinder #1 had a low compression by 1% and that cylinder #4 had low compression by 4%. They sent me on my way after telling me that it might be a slightly stretched timing belt and that they would charge $600 to replace it. What a joke! I am at a loss as to what might be the problem. I don't know how to check for vacuum leaks, but that may be the problem. The only other thing I can think of are the fuel injectors, which I don't know how to test. My truck's temperature gauge is also slowing going up and down between 1/4 and 1/2 when it is idling.

I have changed the DPFE otherwise known as EGR Sensor and I have changed the Idle air control and I have cleaned the throttle body.

My P0401 code is gone. It was a plugged up intake manifold port going to the EGR valve.


Thanks for your help!

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Saturday, April 20th, 2013 AT 2:39 PM

44 Replies

Tiny
2CARPROS KEN
  • ADMIN
  • 11,727 POSTS

With that many miles I would think you have an intake valve that is leaking which would account for the rough idle. Let confirm the problem by doing a compression check

https://www.2carpros.com/articles/how-to-test-engine-compression

This guide may help as well.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please let us know what you find so it will help others.

Best, Ken

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Thursday, March 9th, 2017 AT 2:16 PM
Tiny
EDDIE1329
  • 1996 FORD RANGER
  • 2.3L
  • 4 CYL
  • 2WD
  • MANUAL
  • 150,000 MILES

Replaced plug wires. Code read cylinder one foul.
Put new wires on. Read a lot on this topic and I cannot just throw money at it trying to diagnose. Drove truck day before a one hundred mile round trip no issues. Next day started up and idle is terrible shakes bad in first, second and third gear.
Help!

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • 1998 FORD RANGER

Engine Performance problem
1998 Ford Ranger 4 cyl Two Wheel Drive Manual 51000 miles

My ranger has a rough idle. I have cleaned the maps sensor and the trottle body. Can you help?

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
  • 10,535 POSTS

Your PCV valve could be bad OR the EGR valve could be plugged.

Also take off the IAC and make sure the pintle is moving freely.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

Would the idle air control valve play a part with rough idle? Also how do you clean the EGR valve? There is no pcv on my truck. Thanks.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
  • 10,535 POSTS

To clean the EGR you have to unbolt it and clean its ports and the ports on the engine.

The IAC is the idle control valve and it is a big part of how the vehicle idles.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

Would the throttle position sensor effect the idle?
Thanks again, Kerry

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
  • 10,535 POSTS

Yes it could cause it to idle rough by telling the injectors to pulse out extra fuel causing it to rev up and down.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

Is there a certian type of cleaner for the throttle body etc.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
JBS111096
  • 1994 FORD RANGER

Engine Mechanical problem
1994 Ford Ranger 4 cyl Two Wheel Drive Automatic 92,000 miles

Hello,

I have replaced spark plugs ( they were jacked ) and had the injectors cleaned. I have plug wires to put on but haven't done that yet. I still have a vibraton/ rough idle to the point where you can feel it in the steering wheel and see it on the dash and even feel it on the floor. Runs like a top when moving and gets great gas mileage.

My buddy said mounts are fine. What could this possibly be?

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
  • 10,535 POSTS

Carb cleaner mainly would be for the throttle body, you can use brake cleaner or QD contact cleaner for it. I use the carby cleaner.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
  • 68,407 POSTS

Have you checked for vacuum leaks? Has the check engine light come on?

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

I have a 5 speed manual tran. How much play should there be on the drive shaft where it goes in the extension housing? When I take the truck out of gear the small viburation goes away. The truck has a new clutch.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
JBS111096
  • MEMBER

No check engine light problems and I think we have ruled out a vacuum leak. Could it be that the timing is off? Again, no issue at all other than idle.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
  • 10,535 POSTS

Sorry but I do not know the exact specs for that.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
  • 68,407 POSTS

I would think that if it was timing, it would be felt all of the time. To me, it sounds like a vacuum leak or maybe there is a carbon build up in the EGR and it isn't working properly. Also, I don't know the history of the truck. If it has had a rough life, you may want to check compression to make sure that you don't have a weak cylender.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

I have cleaned all parts you mentioned except the EGR, when I rev the engine it comes back to idleal most all the way, then in about 5 to 10 sec. It comes all the way back. Any help? Thanks for your helping me.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BRODERICK1
  • MEMBER

Please help. I have replaced the egr, Iac, cleaned the TB, MAF, Also done a Motor vac. Replaced plugs and wires,
there are no codes, this only happens while driving the truck does not want to return to idle. It wants to stay reved when I let off the accelerator for about 15 sec. In nuteral clutch in it operates fine.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
SUPERRAT
  • 1994 FORD RANGER
  • 15,000 MILES

94 Ranger, 2.3 with manual trans. Developed rough idle or miss. Runs good at hi rpm's. When warmed up rough idle at startup or miss. Really notice at stop sign when I take off sputters around till engine reaches higher RPM'S then runs good. I noticed if engine does idle normal then suddenly rpm's will drop & engine runs rough for a few minutes then takes off & runs normal. Thank you for any information on this problem.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)
Tiny
BOCHEVY13
  • MEMBER

With the engine running and hood up, spray some ether around the intake manifold where the gasket should be. May be a blown plenum gasket, had a ford explorer do that in the past. It was a V6, but I am also having that same problem but havent gotten a chance to fix it yet.

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Thursday, March 9th, 2017 AT 2:17 PM (Merged)

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