Technical 1242cc Panda Ignition Cuts Out (But ONLY in 1st Gear)

[MArkJohnAsh]

Hi All.
New member here.

I have had a 8v 1242cc Manual Panda for a while now and love it for what it is but have had an ongoing problem with it for 2 years +

Im mechanically competent doing all my own spannering on my own cars but Im not super electronics literate. There have been lots (49) of Alfa's, a 74 Spider, a 147 GTA , an 1971 850 Coupe, 16v integrale, Uno and currently and 2015 Lotus Evora. My bright yellow Panda is still a favorite.

I have silly competitions with myself about how little I can get it to use and have got it with a lot of effort to 58 MPG average for my old weekly work commute

My issue with the Panda is that (ONLY IN FIRST GEAR, COLD or WARMED ENGINE) it wont let the engine rev past around 3000 RPM 50% + of the time. Its not a "soft" stop, its like you turn the ignition off. Calling it a flat spot is being generous, more like a pit of despair. Its so bad and unpredictable that I have changed my driving style so I always change to 2nd before getting to 3000 RPM in 1st. Doesn't matter if you hit this rpm at full or light throttle, it just stops and you end up bunny hopping and having cars behind you almost hitting you

I am thinking that this possibly may be a emissions thing FIAT has mapped into the ecu but it would be pretty brutal if that's the case

If it was something like a AFM or electrical (excluding ecu mapping) it would happen across all gears. I also though the ECU may not let you rev the car in First gear when engine is cold but the problem happens across the engine temp range (and goes on to let it rev in higher gears)

As a fault diagnosis measure I have thought about disconnecting the sensor that the ECU measures speed from to see if this tricks the ECU into doing something different but dont know what the ECU measures speed from (ABS wheel sensors maybe? or speedo?, unsure)

Other than this it runs fine and has continued to for 20,000 miles giving great gas mileage.

Any ideas from anyone?

Cheers

Mark

 

[koalar]

I have no idea why it only fails in first gear

The only electrical connection between the manual gearbox and the electronics is the reverse switch

Revs are limited in reverse on some car. I don’t know if they are on the Panda and I don’t have mine here at the moment to check

 

[koalar]

ASR, ESP warning lights aren’t coming on are they ?

What year is your car

 

[DaveMcT]

Check the usual suspects - coils, leads, plugs and crank sensor and check the earth lead to the engine ECU. While in there, check the reverse switch wire and connector. It's a couple of minutes to take a look (though probably not the cause).

 

[The Panda Nut]

Classic case for MES so you can check parameters of bits n pieces. Please can we go back to cars without ECU's They are great when they work but if they dont work 100% of the time they are worthless, so they are worthless!

 

[koalar]

I have to admit even if I am driving hard I doubt I ever go over 3K in first gear

Then again it’s mostly flat around here and first is mostly redundant

 

[MArkJohnAsh]

ASR, ESP warning lights aren’t coming on are they ?

What year is your car

No error codes or lights on. Car is a 2012 (169 Chassis)

 

[MArkJohnAsh]

No gearbox VSS so I disconnected the LHF Wheel Speed sensor and the Speedo still read and I still had the problem, then I disconnected the RHF Wheel speed sensor and the Speedo still read and I still had the problem, then I disconnected both rear Wheel Speed Sensors, the Speedo didn't read and the problem appeared to go away. This obviously causes the ABS to fault and the electric assisted steering to go "full assist" as the ECU thinks the car is stationary. WTF???? Im confused. Its not as simple as trying another ECU as the 169 is very rare in NZ.

What functions require the vehicle speed.
ABS
Electric Steering
Stability/Traction Control (Not 100% sure it has it)

Any obvious identifiers that a car has traction control. This car is one of the last built 169's and was a "run out" model so may possibly have some of the newer model features

Im leaning towards thinking its something to do with the Traction Control

 

[koalar]

Not making any sense at all

If I take the front wheels off

With the car on axle stands I can put it in gear and drive. The speedometer works fine off the front left sensor only

I do get an ABS error due to the rears not turning which auto clears as soon as you drive a few yards

If your car has (ASR) Anti Slip Regulator better known as traction control a light on the dash will flash and the throttle will be reduced. They normally have a button to switch it off.

 

[RalphM]

I came across something similar on a Renault, if it as the toothed reluctor rings
on the drive shafts are those clean and tight they can crack and when you
accelerate slip giving a false wheel spin flag.

 

[MArkJohnAsh]

Well I am going to have to eat humble pie here. Put a scanner on that read live data and took it for a drive. Looking at throttle Position, when I was driving through the "Flat spot" the output on the scanner was not corresponding at all to the position of the throttle pedal. ie Full down on the pedal only showed 30% +/- throttle then it wammed to 100%. When it was OK (in 1st) it looked normal. In 2nd gear it still did it but not nearly as bad so I concluded it wasn't limited to 1st gear but felt like it. So..... I narrowed it down to the butterfly in the throttle body not replicating what the accelerator pedal position was wanting it to do. Took the throttle body off and gave it a clean with Throttle Body Cleaner. Took it for a drive without the air box on and it sounded like a BDA Escort and had no "Flat" spots and throttle position replicated throttle pedal position

 

[RalphM]

Result thanks for letting us know.