Technical Oh not again. Cutting out over bumps

[portland_bill]

Had a thought, while the idle is pulsing, disconnect the idle control valve connector. I believe the idle valve should stay where it was at the time of disconnection. This may stop it pulsing, or it may stop the engine.

If the pulsing stops, we now know we are looking in the right area. But we don't know if the idle valve is pulsing, or the ECU is pulsing it. You'd need a wiring diagram, but a meter across the right terminals of the connector should answer that one. If valve is faulty, you can try the option of replacement as above. If ECU is pulsing the signal, we need to think again.

If pulsing continues with valve connector disconnected, problem is with ignition or injection.

I'll try to find pin connections tomorrow.

 

[Goudrons]

I had a fiddle yesterday, it started ok when I left work.
I sat and let it warm up and the idle settled as normal before I drove anywhere.
By the time I got 3 miles, it was back up to fast idle.
Turned it off 2 minutes and when restarted it return to normal again and stayed there.

Once home (and idling normal) I checked the Alternator, it's outputting 13.8/13.9v which is a little lower than I imagined it should/would (around 14.4v was what I was looking for)

I left the lights on with the engine off for a while to drain the battery a bit and managed 14v after, I guess the battery was feeding back ok (fullish)and the alt output was minimum because of it.

It continued to idle ok, so I thought if I loaded the electrics up it might dip and trip the high idle
(then I thought I could jump it with another battery and it might return to normal and highlight a problem)
but it didn't dip volts or fast idle, so that put that notion to bed!

So onto the next stab in the dark!

A while ago I noticed the heater gurgling at cold start up, a sound of water bubbling from the passenger footwell, I'd seen a post about it a while ago.
The coolant seemed low so I topped it up, it took around 1.5 litres or so.
Looked again and it's a little low again, not as much as before (and not gurgling).

I can't be certain 'cos I don't drive the Panda as much as the Mrs
(and it's pointless asking her what the gauges read, she takes no notice of the fuel one, why would the temp one be any different?).

But after the first top up the temp gauge seemed to rise much quicker than before
(my other cars are diesel, so anything under an hour or two is quick to me, so it could be just be me)
It seemed to swing a little between half and just under, perhaps air is effecting the ECT sensor once the thermostat opens, hence the 3 mile fast idle trip??

As it was warm up I bleed the system of air lastnight, the heater bleed screw just spat coolant everywhere and seemed ok.

The rad bleed screw didn't do anything except drop the coolant level in the header tank. I couldn't hear any air hiss as the engine was running.

I re topped it up and did it again, and again until coolant started to pouring out and both top and bottom hoses were hot and, after a good squeeze, felt full.

I gave it a good run around after, it didn't fast idle, but that's no indication it's fixed as it was a warm restart and it doesn't tend to do it then.
Got to wait until I get a chance of a cold start.

 

[portland_bill]

1.5 litres is a lot to top up. Level low could lead to problems later, head gasket especially, but for now, keep fingers crossed. Point out temp gauge to wife, emphasise importance and tell her to check every 3 minutes. Or she'll be on a bicycle.

Hopefully if all is bled out, temp sender will be in water and give proper reading. However, coolant has escaped somewhere, need to find the leak. If not obvious, prime suspects are heater matrix, water pump or head gasket. Report back if level is dropping.

 

[Goudrons]

It did it again on the way home from work.

It's "MO" is:
Start up and fast idle as normal.
It warms a little and idle drops to normal, as normal.
Drive 3 miles or so (I'm guessing the thermostat opens around this point) and it trips back to fast idle.

Tonight I got home with it still fast idling, I reached in and unscrewed the rad bleed screw again with it still running, it took a few seconds for the coolant to appear, but nothing happened at that point.
30 or so seconds later, in a bit of a strop, I thumped the top of the ECU in frustration and immediately the rpm dropped to normal.

Now I'm confused what caused it to drop?
The bleed and it took that 30 seconds for the coolant to hit the ECT.
or
The thump. I must stress, it was at the precise moment my fist hit the wiring connectors on the top of it that the rpm dropped.

I pulled the connectors off and gave them a good soak with contact cleaner.
I guess it's another wait and see what tomorrow brings.
I think if it does it again I'll thump it first!

 

[A3jeroen]

I think I suggested cleaning all contacts and connectors earlier.
Soak em in contactcleaner, let them dry out and reconnect with a little vaseline.
That's what I did pre winter with every Fiat I owned since '92. I'd like to think that it prevented me from electrical Gremlins in my almost 22 years of Fiat experience.

gr J

 

[portland_bill]

As A3jeroen said.

Could be coincidence that it dropped with the thump, but cleaning the contacts can only be good. Could be the delay in reading the temp. It appears that you are losing coolant and this needs to be fixed, before more damage is done. Find out where it is escaping and fix it quick.

 

[Goudrons]

Well, I've been touching wood for a while, but four cold start warm ups and the fast idle issue hasn't surfaced again.

It seems I can fix this little car with the odd whack here and there.
You can't help loving the little thing.
Violence really is the answer!

Just trying to think, we've had her since May 2010 (it was 2 and a half years old back then)
She's had:
A rear shocker fixed by the dealer for free.

Three services, done by me for around £30-£40 a pop, depending if I changed the plugs or not, could have done it cheaper, but I used genuine filters.

Four tyres, £118 from Mytyres, I've got two news ones in the shed someone gave me.

Front Brake Pads, fitted myself for around £20

A back box, this wasn't quite new (the new cheapo React one caused a blockage) got it off a breaker for £25 and fitted myself.

Oh and the drivers seat has split a little, fixed with a seat cover for £9.95.

Now it's had £3.99 worth of contact cleaner,
£10 worth of coolant
£5 worth of intake cleaner.
It's going to bankrupt me!

Thanks for all the help and Merry Christmas everyone.
PS A3jeroen, you were right (I hope)!

 

[A3jeroen]

I hope so too
My spanish Panda (Marbella) was the cheapest car ever. We bought it for €200 without MOT. It needed two headlights, exhaust (from the breaker) and four tires to get it MOT'd (about €200 in total).
A few months later the tank leaked so I got another one from the breakers (€25). After fitting it leaked just as bad so got a replacement one with €30 worth of gas in it.
We've had it for two and a half years and about 50.000 Km's and sold it for €500.
Let's just say my current 100HP has cost me more in the past two months I own it.

gr J

 

[Goudrons]

Feck, it's got more problems (or is it the same one?)
MIL lite today.
I managed to wrestle P0130 - O2 Sensor Circuit Malfunction out of it with my home made/free software scanner.

I noticed the LT fuel trim was -39 to -40.
Though ST fuel trim hovered between plus or minus 2 or 3.

Now what's causing what?
Is the O2 sensor at fault and causing the fueling to alter (richen up)
or
Is the fueling at fault causing my P0130?
02 Sensor Circuit Malfunction

Read more at: http://www.obd-codes.com/p0130
Copyright © OBD-Codes.com
02 Sensor Circuit Malfunction

Read more at: http://www.obd-codes.com/p0130
Copyright © OBD-Codes.com

 

[portland_bill]

Very likely to be a failing lambda sensor. There should be two, one before the cat, one after. Your code should state sensor 1 or 2. To test, you could swap them over and see if problem moves to the other one.

 

[Goudrons]

Well there's been progress, though not much.

Tested the O2 sensor and it works ok.
Had it in a blowtorch and it swings up to 0.9v when glowing red, take it out and it drops to 0.1 or 0.2 almost instantly.

I couldn't test the heater side of the sensor, but as lucky as I am, I had a new O2 sensor sitting on the shelf, so that went in and works ok too.

What I have noticed via my scanner is that it trips
"Open Loop System Fault"
It does this under the same conditions as (and instead of) the fast idle conundrum.
ie,
Cold start,
Warms up,
Runs for a few minutes (I think I need to touch the throttle)
Then instead of fast idle, it reports "open loop system fault",
Switch off for 2 or 3 minutes and it runs fine (and the Open Loop System Fault disappears) as long as it doesn't go cold
Goes cold? Then it's another cold start and a repeat performance!

I believe this "Open Loop System Fault" is due to missing/unbelievable (ECU doesn't believe) signals from the upstream O2 sensor. (hence the P0130)

So a wiring fault?
OR
Does my earlier thump of the ECU tell me anything. Like there's a dodgy connection in there somewhere?

 

[portland_bill]

How many O2 sensors has it got? Should be two, one before cat and another after. This is a closed loop system, so an "open loop system fault" is misleading. Are you sure that is the error you are getting.

You have tested one sensor, what about the other one. I think the second sensor is dead.

 

[Goudrons]

The post cat sensor hovers around the 0.1v mark, give or take a few.
This I believe is correct and shows the cat is working well.
The post cat shouldn't oscillate too much and return a low reading.

 

[Goudrons]

This seems to have been solved.
But I can't for the life of me, say 100% sure, what exactly solved it!!

I pulled all the connectors, to ECU, ECU to fuse box, the fuses and fuse board, the relays, O2 connectors, all the connectors to the rest of the sensors and cleaned them.

Wire brushed and cleaned up the earthing points, fuse box to body, engine to body, ECU to body etc.

I swapped over the upstream O2 with a new one I had (it switched just the same as the old one)

In went a bottle of Cataclean, in went a bottle of injector cleaner.

I'd already cleaned the TB and the ICV, but did it again for luck!

Finally I swapped the old upstream sensor with the downstream one (same data log pattern as before, but the upstream switching and STFT seemed to have leaned out a little)


Seems she's back to normal, no more P0130, no more "Open Loop System Fault"
Idles like a purring kitten and roars like a lion when booted (well more like a feral cat really)
MPG seems to have improved as well.
Been fine over a week now.

The only thing I can point to for sure is the downstream sensor effecting the fuel trim and how the upstream switched as after changing it over it all evened out.

I'm only guessing, but I think the downstream might have been reporting intermittently, perhaps some sort of heater issue (like the sensor wasn't heating quick enough) and to protect the cat, it forced the fueling over, which sent the upstream over the edge so it didn't switch often enough causing the P0130 and the open loop fault.

That's what I told SWMBO and I'm sticking to it!

 

[Thorny]

Hello all. I am Thorny and I have registered here with the sole purpose of telling you how to cure this problem.

My wife's Panda is an 08, 8 Valve 1200cc Panda Mammy model.

Within the warranty we started having this problem.

The dealers said it was the earth strap which wasn't covered under so called wear and tear.

Nothing changed and for years various garages have changed so many parts that it's cost us close to a grand and it continued to happen.

Although I am used to doing my own mechanics my wife never put her faith in me being able to fix the car, especially as the garages couldn't.
It was only through despair and a near death experience caused by the engine cutting out at a critical moment that she agreed to let me take a look.

Now I should say that there are many new components on the car which the garages assured me was causing a) cutting out over even the slightest bump
b) idling at 1100 RPM
The list includes an earth strap, every sensor mentioned in the thread above this post and even the brake light switch.

So I decided the first thing I would do is change the plugs and HT leads which the mechanics dismissed as not a likely cause.

The result of this was that the car instantly idled at around 800 RPM when warmed up. The engine ran like a sweet little sowing machine.
I noted that one of the plugs showed signs of over heating.

But the bad news was that the cutting out still happened.

Last night I drove a circular route of around 2 miles to the chip shop and back. The engine cut 32 times. I tried all sorts of running tests but couldn't get the car to cut out myself. It just happened on bumps and some of those bumps were barely noticeable.

So when I got home, rather than collapsing on the settee with my chips, I opened the bonnet and with the engine running, tugged on the cables running out of the ECU. Bingo, every time the engine would cut yet it would start back up straight away when I turned the key.

This was entirely repeatable. So I push the multi block connector in as hard as possible and since then I have crashed over every pot hole and speed bump I could find and the engine hasn't cut out once.

 

[A3jeroen]

And then you enjoyed your chips

Good to report here!

gr J

 

[Wee Smurf]

Very annoying that in the end it was something so simple! But at least it's now sorted.

 

[Thorny]

Very annoying that in the end it was something so simple! But at least it's now sorted.

I'm glad it was something simple but quite annoyed at how much money we wasted by going to the experts.

I have never seen anyone report back that they solved this problem before so I hope that I can at least help others save all that money and time.

 

[Wee Smurf]

I'm glad it was something simple but quite annoyed at how much money we wasted by going to the experts.

I have never seen anyone report back that they solved this problem before so I hope that I can at least help others save all that money and time.

I know what it's like to be out of pocket with the cost of repairs. My bill for Dez's problems came to twice your cost, and much of that was due to the work of the Fiat "expert" I had entrusted my Panda's care to.

 

[portland_bill]

My wife's Panda is an 08, 8 Valve 1200cc Panda Mammy model.

Post a pic of the Mamy, more orange is needed on this forum.