Surging RPM whilst driving

[boston]

Replaced map with genuine ford and all the map and turbo issue never came back. I've not put the ford maf in yet. I reset kam. Now took on a test ride and still surging. I looked at the pedal PIDs. They do not follow the surge. I've added a pic of the turbo and maf whilst surging. I now have a P1102 fault code. Getting closer!!! (Green is turbo) @airline tech

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[airline tech]

If the (Blue) Trace is the MAF - it's all over the place and should be a more stable signal.
I would install the (Ford) MAF sensor and see if it becomes a more stable reading, you can also go through the wiring checks for the signal wire and or have that PID up (At Idle) and shake the wire harness and connector and see if the signal jumps around

From what I can tell it's either a bad aftermarket MAF or a bad Signal Wire circuit, the surging is due to the MAF signal

With the aftermarket MAF - it appears to be doing the same as the (OEM) MAF and same symptoms you had initially - so if you have the new (Ford) in hand install it and note any change if still the same dig into the wire checks or at least replace the MAF connector, I suspect that a connector shake and harness shake test may reveal a signal jump on the PID

I suspect (In order)
Bad Connector (Contacts) - Spread or wire strands broken at the connector
Bad MAF
Bad Harness - damaged wire inside the harness

If I could see the wiring diagram - this would make it more simple - by disconnecting the PCM end of the circuit and (Resistance Check) the circuits but having the knowledge that a (Ford) MAP cured some of the issues tells me that possibly a (Ford) MAF will either cure the current issue or provide the same results - if provides the same results then a deeper dive into the wiring or that connector will be needed.

 

[boston]

Now with Gen Ford installed. Red is MAF Blue is Turbo. Much cleaner lines. Faults are gone besides the P1102. The surging's is far less. Prob 80% less. I suspect a leak somewhere. These are screen shots of the surging. @airline tech

 

[airline tech]

The way it is spiking - leads me to think its a signal issue and or a bad ground

Going on the (Assumption) that the connector is wired (Left to Right - using your pic)
Blue = IAT Signal
Green = 12 Volts
Redish / Orange = Ground
Green / Orange = MAF Signal

I suspect either a bad ground or a bad signal being sent to the PCM

If the wiring is (CONFIRMED) to be exactly this try @ Idle

Back Probe the MAF Signal wire (Red Lead to Signal Wire - Black Lead to Battery Negative
Does the reading match the (PID Data) - Erratic

While still connected above (Jumper-Wire) the Ground Pin (Via Back Probing) to Battery Negative
Did the voltage & PID - smooth out

If it smooths out - It's a ground issue

If It is does not - while still connected (shake the connector and harness) - look for the meter and PID to react via the shake test - if it reacts - bad signal wire or connector pin

 

[airline tech]

Out of curiosity - as another possibility I thought about, as we can see the MAF signal is erratic but have yet to 100% confirm is it truly a signal issue or is it a (bad command) issue from another sensor (Input) to the PCM
You have eliminated the (EGR Valve) and have checked the TPS & APP PIDs

I suggest checking the Temp Sensor PIDs
IAT
ECT
CHT
AMB or OAT
and

The EGRT - EGR Temp - I am curious if this temp reading is affecting the MAF sensor reading

 

[boston]

Out of curiosity - as another possibility I thought about, as we can see the MAF signal is erratic but have yet to 100% confirm is it truly a signal issue or is it a (bad command) issue from another sensor (Input) to the PCM
You have eliminated the (EGR Valve) and have checked the TPS & APP PIDs

I suggest checking the Temp Sensor PIDs
IAT
ECT
CHT
AMB or OAT
and

The EGRT - EGR Temp - I am curious if this temp reading is affecting the MAF sensor reading

Should I see an erratic response coinciding with the MAF?

 

[boston]

Out of curiosity - as another possibility I thought about, as we can see the MAF signal is erratic but have yet to 100% confirm is it truly a signal issue or is it a (bad command) issue from another sensor (Input) to the PCM
You have eliminated the (EGR Valve) and have checked the TPS & APP PIDs

I suggest checking the Temp Sensor PIDs
IAT
ECT
CHT
AMB or OAT
and

The EGRT - EGR Temp - I am curious if this temp reading is affecting the MAF sensor reading

As you can see I have 2 EGR temp PIDs I'm assuming that EGRT is not used as it just sits at -40. Besides this it seems ok. I dont have a CHT PID either. Ill check wire on MAF today

 

[airline tech]

Those look good, and there is another possibility for this system and that is:

A restricted exhaust system or clogged DPF or leaking creating backpressure disturbance which in turn is causing the MAF sensor and EGR Valve to become erratic.

Just another thought of a possible

But for me - the issue still looks like the MAF wiring on the signal wire and or the ground

 

[boston]

Update. As I said I'll update till it's found.

I replaced the egr, put it in wrong. Garage replaced with genuine ford. Maf and map replaced. Dpf and exhaust temp sensors replaced. All faults now gone. However rpm.surging still there ffs!

Had an auto electrician have a look at ecu. All good.

Off to Ford specialist garage on the 26th to investigate.
Lastly the gear box seems to shift hard but I'll deal with that after rpm surging.

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