Technical Rough running at idle and serious judder at low RPM in gear

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Technical Rough running at idle and serious judder at low RPM in gear

Don't beleive it will work but I'll try anyway if it's free.

One of those links I posted before they are specifically talking about how the torque app would not work with a 2000 punto.

Paul
 
Bluetooth ELM327 dongle doesn't even light up ? XXXXXXX

Edited....

Okay I got it to work now.

This is some log that I did, plenty of fault codes which I cleared and have not come back since;

https://jpst.it/Wh-G

Car still running badly but does not seem to stall even with the throttle position sensor plugged in, but it still feels like it would really like to.

Weirdly I found that putting the rear window heater on seemed to stop the chokes at idle but this still didn't improve the driving judder. Could this mean there is some kind of over voltage problem affecting the ignition circuit maybe ?

Gf tried a bit of monitoring whilst driving using the graphs in alfaobd. Found that

Injection time varied between 1-10 milliseconds
Lambda sensor cycled between 19 - 800 mv

Anything significant ?

Can anyone suggest things to look at now it seems like I actually can ? I wanted to check the fuel pressure but can't actually see anything for it in AlfaOBD. Will try the torque app and anything else I can find but I'm expecting from what I've read that only Alfaobd program is likely to work.

Cheers,

Paul
 
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Bluetooth ELM327 dongle doesn't even light up ? XXXXXXX

Edited....

Okay I got it to work now.

This is some log that I did, plenty of fault codes which I cleared and have not come back since;

https://jpst.it/Wh-G

Car still running badly but does not seem to stall even with the throttle position sensor plugged in, but it still feels like it would really like to.

Weirdly I found that putting the rear window heater on seemed to stop the chokes at idle but this still didn't improve the driving judder. Could this mean there is some kind of over voltage problem affecting the ignition circuit maybe ?

Gf tried a bit of monitoring whilst driving using the graphs in alfaobd. Found that

Injection time varied between 1-10 milliseconds
Lambda sensor cycled between 19 - 800 mv

Anything significant ?

Can anyone suggest things to look at now it seems like I actually can ? I wanted to check the fuel pressure but can't actually see anything for it in AlfaOBD. Will try the torque app and anything else I can find but I'm expecting from what I've read that only Alfaobd program is likely to work.

Cheers,

Paul
For reference the early puntos 1999 / 2000 were obd2 compliant

However 2001 - 2006 were different in the sense that they used a different protocol to communicate
They had yellow emls for exanple and early had red

Silly thing but they are compliant and do worm fine!

As for injection variance should be occouring depending on the other sensor inputs, which is a good sign its actually controlling fuel inputs

Lambda should fluctuate, the car is striving to reach perfect burn (lambda one or stiometric ratio 1)
As a result it riches and leans the fuel.mixture and u should see a peaking and troughing of lambda on a pre cat sensor

Ziggy
 
For reference the early puntos 1999 / 2000 were obd2 compliant

However 2001 - 2006 were different in the sense that they used a different protocol to communicate
They had yellow emls for exanple and early had red

Silly thing but they are compliant and do worm fine!

As for injection variance should be occouring depending on the other sensor inputs, which is a good sign its actually controlling fuel inputs

Lambda should fluctuate, the car is striving to reach perfect burn (lambda one or stiometric ratio 1)
As a result it riches and leans the fuel.mixture and u should see a peaking and troughing of lambda on a pre cat sensor

Ziggy
But I thought the whole point of what OBD2 means is the protocol?

And yes I have the red engine management light meaning I have something older which I already knew.

I'll try the torque app tomorrow, at least it might help others to know what might / might not work on a 2000 punto.

I should add that I removed a resistor labelled R4, though I'm not completely sure I needed to. The reason for doing it was that I thought that maybe the unit wasn't working due to something i'd read about needed to remove a resistor that was between pins 6 and 14. Anyway it luckily still worked when I realised I hadn't initially pushed the dongle thing in far enough.

Looks like nothing abnormal seen yet then. There's almost too much data now and plenty of driving symptoms as well. I can actually smell fuel a bit now so I'm concerned I have a fuel line leak. That's part of the reason I would have wanted to check fuel pressure.

Symptoms are, to summarise;

-Rough Idle but didn't actually stall earlier even with throttle position sensor plugged in.
-Horribly jerky at low revs or when taking foot off accelerator.
-Slight smell of fuel outside the car somewhere.

Paul
 
Look at the obd2 protocol as been a sort of irish,scotish,american, british versions of the "English language"
All same thing - but slight variations

Most generic obd2 scanners can talk to them
I did havenissues with a 2000 pug x reg but thats probably cause its french tbh...

Ziggy
Okay thanks, I'll try some other apps tomorrow then see if I can get a fuel pressure reading. Maybe it's just not possible on my ECU ?

If anyone has any suggestions on what data to look at or log regarding this I'd be most grateful. I've tried new plugs, leads, coilpacks, MAP sensor so I don't believe any of these to be the issue. I'll see if any new fault codes come up in the next couple of days since I've now cleared the old ones. Not expecting anything though as I have not actually had the engine light come on other than when I have myself removed a connector to MAP / TPS.

Paul

Paul
 
Okay thanks, I'll try some other apps tomorrow then see if I can get a fuel pressure reading. Maybe it's just not possible on my ECU ?

If anyone has any suggestions on what data to look at or log regarding this I'd be most grateful. I've tried new plugs, leads, coilpacks, MAP sensor so I don't believe any of these to be the issue. I'll see if any new fault codes come up in the next couple of days since I've now cleared the old ones. Not expecting anything though as I have not actually had the engine light come on other than when I have myself removed a connector to MAP / TPS.

Paul

Paul
Multi ecu scan should do what u need on free version
If 20mins aint enough time restart the software and go again :)
 
Okay,

Multi ecu scan works but the torque app doesn't. With torque it connects and then tries to find the correct protocol but it never does and consequently it just hangs on 'connecting to ECU' or whatever it was.

Couldn't really see any issues in multi ecu scan, but again, I don't really know what values are good or bad. I suspect the idle control valve isn't moving as fast as it should. Now I've meddled around a bit its idling at much higher rpm but still judder when driving, though potentially not as much.

All this aside I've now noticed the bottom of the fuel tank is wet so it's going to have to go to the garage anyway to look at that first.

Could a fuel leak explain the other symptoms ? I can't be really sure where exactly the fuel is coming from.

Paul
 
Garage said that removing the fuel tank to look would cost 100's as the bolts and brackets etc are rusty.

Looks like I'm stuck with the leak.

Anyone have any idea why using electrics would make the engine run slightly smoother when idling ?

Paul
 
Fuel pump replaced, unfortunately didn't cure the rough running at idle and juddering.

Not sure what to try next. No fault codes and don't really know what to look at using OBD connector.

Paul
 
well next step is measuring compression, does it also misfires when its hot?
you sure this light isnt on?

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Definitely no light, and it works because it illuminates when I remove for example the throttle position sensor cable.

It misfires (at least I think it's a misfire) when hot, both at idle and when giving it throttle. It feels like it 'skips' a couple of times a seconds if that makes sense, and this causes a judder. At idle it maybe does this once every 2 seconds or so and causes a stall eventually.

I could try and get hold of a compression tester kit, what will it tell me if there is a problem in one of the cylinders ? Piston rings ?

Cheers,

Paul
 
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I checked at night, didn't see anything but changed the leads anyway. I think there's a slight improvement.

Maybe I shouldn't have fitted cheap Bosch spark plugs ?

How possible is it to change a head gasket at home, with minimal tools, knowledge or competence ?

And does anyone know how the hell I can stop fuel leaking out of the top of the tank, considering I've bought a new fuel sender unit, locking ring and gasket as well as the special tool to do the thing up ? Is there some special procedure I'm not seeing regarding lining up the locking ring or something ?

This car is a living nightmare.

Paul
 
top plastic nut isnt tight enough and it leaks, or you didnt put that rubber round seal on good enough

for head gasket you can do everything at home apart from head resurfacing, better to bring it to a shop

never did it at home but still




but first find out what the compression is on the cylinders
 
Alright cheers, I think if it's the head gasket I'm probably screwed as no way to get head skimmed, do people normally remove the whole engine then and take in another car to garage ?

Paul
 
Hi there. I'm new here and was just reading through your post. I have the exact same problem with the car juddering really badly when at low revs or taking my foot off the accelerator! Have you managed to find out the problem?
 
Sorry to butt in guys - I have a Cinquecento. The misfiring/kangaroo petrol/stalling took me a few days to suss out. There were no error codes ..

Disconnect the electrical connector on the MAP and run the car. If the symptoms disappear or seem to have 'eased' .. suspect the MAP.

As a rough rule of thumb, worn piston rings burn oil and leave a cloud of smoke behind when you accelerate. A burnt or split exhaust valve can cause what feels like a misfire. A compression test followed by a 'wet' compression test can help identify the problem

** Before anybody rushes off and pays lots of money to have a new head gasket .. try one of the modern head-fix additives. I'm told that the 'steel seal' is excellent.
http://www.ebay.co.uk/sch/i.html?_odkw=punto+map&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR6.TRC0.A0.H0.Xcylinder+head+fix.TRS0&_nkw=cylinder+head+fix&_sacat=0
 
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