Idle Problem

Tiny
SCOOBYTECH
  • MEMBER
  • FORD EXPLORER
I have had several people look at this problem but no solutions yet.

1995 Ford Explorer 4.0 4WD with 205000 miles

Vehicle starts fine. Accelerates fine. When at cruising speed (constant speed) I notice some hesitation. When stopped at light, car will idle fine and then drop sharply and back up. It will do this repeatedly and then shut off. I was receiving some EGR codes that have not reappeared since changing EGR Valve. However the problem still remains. Could it be the PCM? If so, is there a way to test the PCM?

Items that have been replaced:

Ait Filter
Fuel Filter
Spark Plugs
PCV
TPS
EGR Valve
DFPS Differential Feedback Pressure Sensor
Idle Air Control Valve(motor?)

Throttle body has been cleaned.
Monday, June 18th, 2007 AT 1:35 PM

5 Replies

Tiny
DONNY BRYSON
  • MEMBER
  • 13 POSTS
I would check the TPS and maybe your fuel pump could be getting weak.
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Monday, June 18th, 2007 AT 6:18 PM
Tiny
SCOOBYTECH
  • MEMBER
  • 3 POSTS
I already changed the TPS with no results. If the fuel pump was getting weak, would it show on acceleration as well? Is there a way to test the pump besides testing the voltage?
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Tuesday, June 19th, 2007 AT 4:29 PM
Tiny
98RANGERXLT
  • MECHANIC
  • 301 POSTS
If the fuel pump was getting weak you would know when you fill up the vehicle will cut off and on
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Tuesday, June 19th, 2007 AT 8:27 PM
Tiny
SCOOBYTECH
  • MEMBER
  • 3 POSTS
I haven't noticed that when I fill up. I will see on the next fill up.

I was thinking it might be the MAF sensor? I checked the voltage TO the sensor(at the MAF connection with KOEO) and I am receiving 5.83 volts. According to the Haynes manual, I should be getting battery level voltage (anywhere from 10 to 12).
Is this true?
If so, could this be the problem.
A short or maybe a bad PCM?

Thanks for your feedback!
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Wednesday, June 20th, 2007 AT 7:14 AM
Tiny
98RANGERXLT
  • MECHANIC
  • 301 POSTS
Also there is a sock on the end of the fuel pump that will get dirty check that also.
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Wednesday, June 20th, 2007 AT 7:41 PM

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