Surging RPM whilst driving

[boston]

From the busy overlay of data - it looks like the EGR Valve is hunting for correct position.
So:
Sticking EGR Valve (or bad position sensor-feedback)
Clogged or restricted EGR Tube - causing low flow (on MAF) and PCM is trying to adjust
Bad MAF feedback not seeing the EGR Flow


Try displaying the PIDs in a (data) vs (graph) and include the MAF response

Tighten it up with only - to get a better view of what the EGR Valve is doing

EGR Desired
EGR Command
EGR Actual
MAF
RPM

The MAF should drop (smoothly) when EGR is flowing, if it fluctuates it will cause the EGR Command to attempt to adjust the EGR valve until it sees the correct response, so this can be restricted EGR flow (tube) and the MAF reading correctly or the actual MAF - not seeing the actual flow

Summary:
From what I see - in that busy PID data is the EGR Valve is hunting for correct position and its erratic
Now it just needs to be isolated down to is it the EGR Valve sticking - slow response to movement or is it restricted EGR flow (Tube) or the MAF sensor not responding to the flow.

EGR Desired should remain stable until commanded to change
EGR Command - adjusts to EGR Desired, then fine tunes the command from the actual flow response (MAF)
In a normal operation - the EGR Command and the Actual should match (closely)


NOTE:
I cannot see the manuals for the 3.2 variant - from what I can tell, the 3.2 does not have the DPFE sensor (used for EGR Flow) the same as the 2.3 does - the 3.2 uses the MAF instead.
However, there is a DFE sensor that is used for the particulate filter, and this creates conflicting information due to the close naming of the 2 sensors, so if I am correct here you do not have a DPFE and the MAF is providing the feedback the same way the DPFE does for the 2.3 engine.

Airline tech you are indeed a legend. I've created a csv and had AI review the data and this is the same result. You are right! I have the CSV file for review if you or anyone would like to see it. Its comprehensive data of my last drive. I will indeed do as you said and make it less busy and post here. And I will keep everyone updated as I'm sure someone else will have this issue. Im going to replace the EGR to start.

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[boston]

Have you checked for any DTC codes?

Yes, nothing there

 

[boston]

I have ordered the EGR. Im going to take the manifold etc. off and clean and replace EGR. Im looking to do it this weekend. Wish me luck. I will up date as soon as its done.

 

[boston]

Job has begun. And holy crap it sucks. Im currently trying to get the cooling hoses off. I'll update tomorrow for all who want to hear the pain.

 

[boston]

I've replaced the EGR and carbon cleaned intake manifold. All nice and clean. And the problem is still there!!!!

Thinking MAF sensor next.

 

[boston]

Ok, changed MAP Sensor and we'll. Still getting surging.

Any ideas?

 

[airline tech]

Ok, changed MAP Sensor and we'll. Still getting surging.

Any ideas?

Replaced (MAF) or (MAP) sensor?

I would pull the PIDs for the senor (MAF) and note any glitches in the reading, engine running, the MAF sensor is the feedback for the EGR Valve not the MAP

I would also pull the PIDs for the APP (Accel Pedal) (X2) and (TPS) with only (Key On) and note any glitches in the readings - it would be easy to see with the engine off

 

[airline tech]

In addition to the above PIDs I would pull up

Fuel Pressure
Fuel Rail Pressure
Fuel Rail Pressure (Desired)

To check for proper fuel pressure at the fuel rail

If the Fuel Rail Press and Desired - do not match closely this may be the root cause of your issues, just a thought of other possibles (if you mistyped) and meant the MAF was replaced

and then the importance of viewing the - TPS and APP PIDs with the engine off to get a good view electrically of full travel

You need to view the following PIDs for the TPS and APP - and watch the PIDs with Key On Engine Off

TPS
Commanded Throttle Actuator Control
Relative Throttle Position
Throttle Angle Commanded
Throttle Angle Corrected


APP
Accel Pedal Position D
Accel Pedal Position E
Pedal Position Sensor 1
Pedal Position Sensor 2
Relative Accel Pedal Position

Move the Pedal - (SLOWLY) - Full Range and watch the PIDs for any glitches

If these are confirmed good - then we need to look at MAF or Fuel Related issues, since the EGR is ruled out.

Now the MAF sensor and MAP Sensor
Steady at idle
Snap Throttle
Immediate Rise (Smooth)
Immediate Drop (Smooth)

And the MAF and MAP should track together

another test would be - hold 2,000 RPMs
and watch for - Stable MAP & MAF

If MAP is fluctuating pull up the PIDs for the Turbo
Might be labeled as - VGT (Variable Geometry Turbo)

VGT Commanded
VGT Actual

and note - is the VGT also fluctuating along with the MAP, this would highlight if the issue is actually turbo influence related
and then monitor the correlation between actual and commanded
Are they steady and tracking together


One of the above tests - should reveal something and give some direction on where the issue is.
I am focusing on things that would produce the EGR Hunting - this is causing the RPM bumps, and the goal is to find the reason for the EGR to hunt.
One of the above signals is generating invalid data and the EGR is just reacting, now it has been replaced and the tube is cleaned - it is ruled out

 

[boston]

I unplugged the maf and the surging disappeared. I've just bought a new one. Do I need to disconnect the battery so the ecu will relearn?

I'll.then record the PIDs mentioned. Cheers guys

 

[boston]

In addition to the above PIDs I would pull up

Fuel Pressure
Fuel Rail Pressure
Fuel Rail Pressure (Desired)

To check for proper fuel pressure at the fuel rail

If the Fuel Rail Press and Desired - do not match closely this may be the root cause of your issues, just a thought of other possibles (if you mistyped) and meant the MAF was replaced

and then the importance of viewing the - TPS and APP PIDs with the engine off to get a good view electrically of full travel

You need to view the following PIDs for the TPS and APP - and watch the PIDs with Key On Engine Off

TPS
Commanded Throttle Actuator Control
Relative Throttle Position
Throttle Angle Commanded
Throttle Angle Corrected


APP
Accel Pedal Position D
Accel Pedal Position E
Pedal Position Sensor 1
Pedal Position Sensor 2
Relative Accel Pedal Position

Move the Pedal - (SLOWLY) - Full Range and watch the PIDs for any glitches

If these are confirmed good - then we need to look at MAF or Fuel Related issues, since the EGR is ruled out.

Now the MAF sensor and MAP Sensor
Steady at idle
Snap Throttle
Immediate Rise (Smooth)
Immediate Drop (Smooth)

And the MAF and MAP should track together

another test would be - hold 2,000 RPMs
and watch for - Stable MAP & MAF

If MAP is fluctuating pull up the PIDs for the Turbo
Might be labeled as - VGT (Variable Geometry Turbo)

VGT Commanded
VGT Actual

and note - is the VGT also fluctuating along with the MAP, this would highlight if the issue is actually turbo influence related
and then monitor the correlation between actual and commanded
Are they steady and tracking together


One of the above tests - should reveal something and give some direction on where the issue is.
I am focusing on things that would produce the EGR Hunting - this is causing the RPM bumps, and the goal is to find the reason for the EGR to hunt.
One of the above signals is generating invalid data and the EGR is just reacting, now it has been replaced and the tube is cleaned - it is ruled out

It was MAP replaced not MAF. I did MAP because I replaced EGR and cleaned all the I take so figured might as well.

 

[boston]

Update to the saga. I decided to buy a Hella MAF sensor made in China. Think it was a big mistake. I get over boost, and other times underboost, maf and map inconsistencies, maf and vaf too. Maf is all over the shop. Im buying a genuine one Monday.

 

[airline tech]

I would go with (OEM)
If after OEM install - it still has issues for control

Try a KAM - Reset
Start Engine and let it (Idle Learn) for about 10 Minutes - do not touch throttle

You may try this with the (Hella) as well

I would also ENSURE the ducting is secure and in good condition between the (Air Filter Housing and the Throttle Body)

I would also do a good visual on the MAF sensor connector and its wiring. as its a possibility since this was disturbed - and the issues got worse - may be a sign of - Hey look at me

Summary
Bad MAF - Sensor Calibration (Aftermarket)
Bad PCM - Learned Data (Airflow Calculation)
Ducting (Leaks / Cracks) after the MAF sensor
Bad Connector or Nearby Wiring (Feeding The MAF)

 

[boston]

I would go with (OEM)
If after OEM install - it still has issues for control

Try a KAM - Reset
Start Engine and let it (Idle Learn) for about 10 Minutes - do not touch throttle

You may try this with the (Hella) as well

I would also ENSURE the ducting is secure and in good condition between the (Air Filter Housing and the Throttle Body)

I would also do a good visual on the MAF sensor connector and its wiring. as its a possibility since this was disturbed - and the issues got worse - may be a sign of - Hey look at me

Summary
Bad MAF - Sensor Calibration (Aftermarket)
Bad PCM - Learned Data (Airflow Calculation)
Ducting (Leaks / Cracks) after the MAF sensor
Bad Connector or Nearby Wiring (Feeding The MAF)

I've booked in for Ford to have a look as well. I disconnected the battery for 30 min ans installed the hella and still bad results. I will leave the hella in and see what ford says. At least it will help the next person.

 

[boston]

Quick question, am I doing this correct as far as putting in the new MAF. Im disconnecting the battery for 30 min then reconnect and idle for 10 min? @airline tech

 

[airline tech]

Quick question, am I doing this correct as far as putting in the new MAF. Im disconnecting the battery for 30 min then reconnect and idle for 10 min? @airline tech

Using the scan tool - KAM Reset procedure is best - this way you have a confirmed reset, but the battery disconnect also works - and let it idle for 10 minutes or so and once it settles down then you can also turn on AC - to let it learn idle (load)

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