g8rpi said:

there is no problem leaving a OBDII interface plugged in

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Great!

g8rpi said:

If you have a multimeter check the resistance between pins 6 and 14 on the interface

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I'll try to get a meter onto those pins tomorrow and see what it says.

g8rpi said:

Where re you located? I'm near Cambridge and could put a break-out box and oscilloscope (and of course Multiecuscan) and try to see whats going on. I love a challenge.

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Unless you have very long leads, we have a bit of a problem! I'm around 500 miles away, just outside Aberdeen! Thanks for the offer of investigating further, but it's probably not very practical.

Update..... I've just been out in the Panda and it really wasn't a happy bunny tonight, even with the Bluetooth OBD plugged in and in the heavy rain we have at the moment. Lots of stuttering as the pedal was being depressed after being up a bit and then feeling rough as she is accelerating or cruising, as if she had a petrol engine with a cylinder going intermittently AWOL, for whatever reason. That's the first big-ish wobbly since my cheapie OBD sender was installed about a week ago.

Unfortunately, I didn't have my tablet to see if it was reporting any issues. I'll try again tomorrow.

g8rpi said:

check the resistance between pins 6 and 14 on the interface. If it is less than 200 Ohms the resistor is fitted.

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There is indeed 120Ω across pins 6 and 14.

If leaving the OBD gadget plugged in, remember that the connection has a permanently live pin which in the case of the Innovate Motorsports WiFi unit I used, meant it remained on and transmitting its WiFi network all the time. This might also be the case with the Bluetooth signal on yours. Mine had enough of a current draw to flatten the battery if I didn't use the car for a week or so. Had to remember to unplug it after that.....

Just a thought.

MikeySkiBoy said:

There is indeed 120Ω across pins 6 and 14.

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Hi,
That explains why it is making a difference. The question is still what is the basic fault. I'd tend towards interference. The first thing to check is earths / grounds and then connectors for corrosion.
Check / clean all earth connections including ECU mounting bolts, battery terminal, Battery to chassis lead, engine/gearbox to chassis lead(s)/strap(s).


Following that you are down to checking all the ECU and engine sensor connectors for dirt, corrosion or loose wires.
If that does not work, it's serious diagnostics including using an oscilloscope to look for noise.


Robert G8RPI.

g8rpi said:

Hi,
That explains why it is making a difference. The question is still what is the basic fault. I'd tend towards interference. The first thing to check is earths / grounds and then connectors for corrosion.
Check / clean all earth connections including ECU mounting bolts, battery terminal, Battery to chassis lead, engine/gearbox to chassis lead(s)/strap(s).


Following that you are down to checking all the ECU and engine sensor connectors for dirt, corrosion or loose wires.
If that does not work, it's serious diagnostics including using an oscilloscope to look for noise.


Robert G8RPI.

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Absolutely. Proper way to do diagnostic. Today's mechanics plug in the PC and if nothing shows up they are stumped. They seem to have no skills out with reading codes then when a real fault shows up the customer is rarely helped.
A scope and common sense will often find electronic issues long before codes are written to the ECU

I forgot to shove the OBDII plug back in after metering it yesterday and the car was fine on the way home. Left it out again this morning and it's been OK all day.

Maybe the OBDII being plugged is another bum-steer and it is just playing me along at the moment. Extremely frustrating!

Sounds like an intermittent fault. Very much like how electronics can be.
I'd be inclined to spend some time as Robert says and check connections, earths and look for corroded plugs etc. Half an hour and a can of De-oxit or WD40 may well effect a cure.

Mines been driving well for last week or so, with only the odd very slight stutter on a morning.

I got in it this morning, and could feel as soon as I started moving that it was going to have issues.

Unfortunately, I'd been called out about 20mins late for work, and had zero time to plug in and grab any readings.

As I suspected, it spent the first few minutes stuttering and surging.

Ventmore said:

Mines been driving well for last week or so, with only the odd very slight stutter on a morning.

I got in it this morning, and could feel as soon as I started moving that it was going to have issues.

Unfortunately, I'd been called out about 20mins late for work, and had zero time to plug in and grab any readings.

As I suspected, it spent the first few minutes stuttering and surging.

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I'd begin to wonder if it was something old-fashioned, like a fuel supply issue, or a dodgy piece of cable - or connectors/earthing as mentioned previously. Do the electronics monitor fuel pressure?

babbo_umbro said:

I'd begin to wonder if it was something old-fashioned, like a fuel supply issue, or a dodgy piece of cable - or connectors/earthing as mentioned previously. Do the electronics monitor fuel pressure?

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I can't monitor fuel pressures with the equipment I have, but I'm sure the dealers box of tricks will.

After 5 minutes or so of driving, the issues mainly clear up, which makes me think there's something mechanical sticking, then freeing up under pressure, or as the engine temperature rises.

I do still get some issues on the road after driving a while, but the motorway speed surges seems to have completely stopped.

I have had a few times where I've been accelerating, and the car has just seemed flat. I actually caught one of those times with my OBD device.



The grey line is engine load, and the purple line is MAP. The first peak is 2nd gear, the second is 3rd, and he third is 4th.

I was accelerating up an incline with my foot on the floor. In 2nd gear, the engine load hits 94% then fluctuates and drops to 74%. In 3rd, it again hits 94%, then drops to 76%. In 4th, it hits 100% and stays there, and I could clearly feel that it was then giving me everything it had.

This could be a related issue, but I'm also wondering if it could have just been a temperature issue. It was the hottest day we've had in a while, and the car was reading 27.5C in the external temperature gauge. Also, the orange line on the graph is intake air temperature, and at the first peak, it was reading 124F, but had dropped to 111F by the time I hit 4th gear.

Fiat customer service called today to say that as far as themselves and the dealer are concerned, they've checked absolutely everything, and there's nothing wrong with the vehicle.

They've now suggested that my only course of action is to try a different dealer.

I hate intermittent faults!

I'm booked in with another local dealer in 2 weeks. Maybe it just needs a fresh set of eyes.

Ventmore said:

Maybe it just needs a fresh set of eyes.

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What's the part number?

gar074 said:

What's the part number?

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? Cheers mate...just nearly spat my drink all over the screen!

Ventmore said:

I'm booked in with another local dealer in 2 weeks. Maybe it just needs a fresh set of eyes.

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Fingers crossed for you!

My one is still playing about occasionally, but I can't really see anything with the scanner tool, nor come up with a routine that brings the fault on. No point taking it back to the dealer because it is clear that they won't do much unless they can unearth a clue.

As this is becoming increasingly frustrating, I might be tempted to sell up and move on to another car and just forget all about it. It's a shame, because she's a good motor when running right even though the rear passenger door can't now be opened from the inside!

MikeySkiBoy said:

Fingers crossed for you!



My one is still playing about occasionally, but I can't really see anything with the scanner tool, nor come up with a routine that brings the fault on. No point taking it back to the dealer because it is clear that they won't do much unless they can unearth a clue.



As this is becoming increasingly frustrating, I might be tempted to sell up and move on to another car and just forget all about it. It's a shame, because she's a good motor when running right even though the rear passenger door can't now be opened from the inside!

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Thanks mate. Hopefully, if I can get it sorted, it may also help you out.

I considered getting rid of mine a few weeks ago, but the going rate for the car I paid 15k for just over a year ago is around 9.5k. Unfortunately, that wouldn't cover the finance, and I'm not willing to lose money on it.

I hope to get it working properly. I've spent way too much money chopping and changing cars over the years, but I've had enough of that now, and this one was supposed to be a car I could keep for a good many years.

I was just googling for a good picture of the position of the EGR when the alert came in for your post. I'm thinking of taking it off myself and checking it over. Don't really want to as I'm definitely no mechanic, but I really need to get to the bottom of this.

This morning I tried revving the engine a little before driving away. The problem still occurred the first time through the rev range. Whatever it is doesn't seem to right itself until the engine has been under load.

Sorry to hear you're still having problems with the door. I'm guessing it's something I'll get to experience at some point as this has been a fairly unlucky car.

Just looking around and came across Celtic Tuning. They say they can remove the EGR and remap the ECU to ignore the fact that it's missing. A remap may even smooth out some of the kinks in the rev range.

I wonder if it may be a route worth investigating. I've had 2WD cars remapped before, but not sure how good of an idea it is with a 4WD.

Maybe it's worth approaching a tuning company just to see if they have any insight on the issues I'm having.

Hi.
You say that with the Bluetooth dongle connected things improve. One quick test. Turn on the radio, select AM and tune it to 531khz. Then switch on the ignition either with or without the engine running, does the radio get very noisy? If so plug in your dongle and if the noise reduces you have an earthing problem. Now it could be anywhere, most likely at any of the ECU s or engine to body. This noise is electronic hash and if it effects the radio so badly it will be sending rubbish to the engine ECU. If you can't find the issue a decoupling capacitor to each of the ECU s supply "might" work.

Thanks for the advice mate.

Ive just tried it, but the radio is noisy with and without the ignition on, and it's the exact same noise either way.

Worth a shot though!

Well at least this discounts earthing and possibly poor connections.
The reason I asked was a friend had similar problems on a 500. He also complained of rotten AM radio reception. I plugged in my dongle and both the radio and running issues stopped. Fault was the engine ECU earthing strap was broken.