Running rough and hesitating - struggles to start

[Bunkle]

I have had a problem with my TDI arosa now for nearly 2 months. When driving along at a steady speed it will hesitat very badly then carry on, it does it when hot or cold but first started when low on diesel. I have changed the fuel filter and air filter. Over Christmas it refused to start so i changed the coolant temp sensor but still no joy. Green Flag got it started by spraying alot of Easystart down the air filter tubing after the MAF. Main Seat garage then diagnosed a dirty EGR which they cleaned up (albeit only charging for 20 minutes labour, thought it would take longer to clean) Since then it is still running rough and hesitating so i have cleaned the MAF sensor and reset ECU after reading various posts. Also it has had a load of Forte diesel treatment.

The car this morning struggled to start AND still runs rough. Any ideas ?

Oh and the weird bit from the is when i turned my radio on after ECU reset it asked for a code which i don't have (SAFE on display), left it off for 2 days and turned it on yesterday and the thing works ! and has remembered all the preset radio stations, HOW ???

 

[cupra.al]

your diesel problem could be an air lock in the fuel system i only think this as i recently had to bleed the fuel system on my work van due to an airlock.

 

[Bunkle]

Cheers for the advice, i still havn't sorted this problem out, It wouldn't start again yesterday so i removed the pump from the tank and cleaned out all the fuel lines but to no avail, i know it's nasty stuff but the only way it would start was by spraying Easystart down the air filter housing, it fired up straight away, could it be the tandem pump ?

 

[gdelargy]

Came here to post about the same problems I've been having with my own TDi.

Similar symptoms to what you describe--I could be driving along at a steady speed and it'd suddenly hesitate for a wee second. That's been recurring intermittently since Xmas for me as well. Then, on Thursday, it failed to start completely after sitting for a day in snowy weather. However, even now it's thawed the car still won't start.

At least I have a couple of ideas to look at thanks to this thread. Still, I just had the car serviced a couple of weeks ago, so to be sitting here with no car is really pissing me off...


G

 

[Bunkle]

Came here to post about the same problems I've been having with my own TDi.

Similar symptoms to what you describe--I could be driving along at a steady speed and it'd suddenly hesitate for a wee second. That's been recurring intermittently since Xmas for me as well. Then, on Thursday, it failed to start completely after sitting for a day in snowy weather. However, even now it's thawed the car still won't start.

At least I have a couple of ideas to look at thanks to this thread. Still, I just had the car serviced a couple of weeks ago, so to be sitting here with no car is really pissing me off...


G

I feel for ya ! - it's driving me mad, if you are desperate to get it started spray some easystart down the air filter housing, disconnect your glow plugs first, i've been told it's not particularly good stuff to use on Diesels but if your desperate it's up to you, I have been back to Seat (again) who have diagnosed blocked injectors due to "bad" fuel, i have now completely drained it of all fuel and started from scratch but to no avail, it is severly getting on my nerves now, Spoke to an injection expert today who have advised the injector theory is unlikely as it would probably be running terrible all the time, i'm at a complete loss now, i tried kicking it yesterday a few times yesterday though

 

[Mr Biscuit]

from what I've read, engine temp sensor could be the culprit.

green ended thingy, battery end of block, with four wires.

£25 fix.

worth a go anyway.

 

[Bunkle]

mr biscuit i will be buying one tomorrow and if it works i will be forever grateful, i take it this is different from the coolant temp sensor as i have already changed that, i have noticed mine takes AGES to warm up, could this be another symptom

 

[Mr Biscuit]

ah no if you mean temperature gauge in dash, its the same device, but has two sensors built in, one for the gauge & one for the ECU.

So perhaps you have already covered this one.

mine takes ages to warm up, perfectly normal, 15 mins or 15 miles on a cold day.

Not sure what else to suggest, worth checking the fuses in the case on top of the battery are all ok & seated ok.

there is another fuel pump on the end of the engine block.

i know all about draining fuel & changing filters, after a brief foray into bio diesel a couple of years back, don't go there.

doubt if its the injectors, unlikely all three would fail.

ah, brake light switch is another one, if this fails, or closes, it throttles back the engine, but this is unlikely to cause the non starting issue.

good luck. let us know how you get on.

 

[Bunkle]

blast !, if i unplug the coolant sensor would i be right in thinking the ecu would just be "told" the engine is cold, just wondering if it's worth me unplugging it and seeng how it runs in case i have replaced a dodgy sensor with another dodgy sensor

 

[Mr Biscuit]

worth a try, might possibly throw a fault though.

I guess the glow plug light comes on as normal, and even two cycles of glow plugs doesn't improve starting?

There is also a glow plug relay which can cause problems, don't know if the light still comes on though when faulty.

 

[Bunkle]

mmmmmm, i'm not convinced but on Friday via a complete fluke i noticed fuse number 32 (engine electrics) was not seated properly, since then it's been running fine !! surely not ...... could i really be this lucky

 

[Mr Biscuit]

I hope it fixes your problem.

I too had a strange fault a couple of weeks ago, a momentary power loss, accompanied by
yellow warning light on dash. (too quick for me to see which one)
Also knocked out my scanguage, so I suspected a power fault.

I checked the fuses in the battery box, & one was loose & not properly seated.

Since then (touching wood), not had problem since.

You & me both fingers crossed!

 

[robreidmotors]

Is it possible that the easy start, rather than igniting as such, helped clean everywhere it went? maybe loosening up parts that were carboned up etc?

On petrols you can use throttle body cleaner, diesels dont have one, im hoping diesel heads will be able to help on this one. Is it possible to use something to clean up from the ducting onwards?

On a simple not id check the air filter also, as dirty ones cause havoc on any car, petrol or diesel.

 

[Bunkle]

Is it possible that the easy start, rather than igniting as such, helped clean everywhere it went? maybe loosening up parts that were carboned up etc?

On petrols you can use throttle body cleaner, diesels dont have one, im hoping diesel heads will be able to help on this one. Is it possible to use something to clean up from the ducting onwards?

On a simple not id check the air filter also, as dirty ones cause havoc on any car, petrol or diesel.

It's back in garage, now in limp mode, now diagnosed as needing a new tandem pump, i am seriously regretting buying the little pain in the

 

[Mr Biscuit]

ah tandem pump is the one on the end of the block, that I mentioned.

maybe its heading my way too?

Though I've had no probs recently.

can get clogged up, particularly after bad fuel / bio.

I've seen diy cleaning done on TDi club USA

 

[Bunkle]

and the hits just keep on coming .......... Ran lovely for 20 minutes after pump change, then died, seems a diagnosis before of a blocked injector may be true as thats what diagnostics is now showing,sooooooo now having injector replaced, £35 road tax=lovely, 65mpg=lovely, £700 bill (so far) to keep it running NOT SO BL**DY LOVELY

 

[CatB1]

Seems like the Tdi's are all catching a similar bug. My daily driver Arosa Tdi refused to start a few weeks ago, had it towed to mates garage, crank sensor was OK & Tandem pump was pressurising to 40psi at cranking speed. Diagnostics was showing injector 1, 2 & 3 to be at fault. Mates garage could not believe all three faulty at the same time. Took it to SEAT main dealers, more checks & diagnosed all three injectors could be faulty. Injectors taken out (diagnostics, labour & cost of sending injectors to specialist) & confirmed all three to be U/S. Originally quoted £300 per injector, now its £220 plus VAT. Bill at the moment is about £1100, car tax renewed today & insurance now also due. The 16V Cupra MOT was done in Feb, the Arosa had a new exhaust, also in Feb to get that through the MOT & the 1.8T MOT is now also due. Oh dear, expensive couple of months.

 

[Bunkle]

Seems like the Tdi's are all catching a similar bug. My daily driver Arosa Tdi refused to start a few weeks ago, had it towed to mates garage, crank sensor was OK & Tandem pump was pressurising to 40psi at cranking speed. Diagnostics was showing injector 1, 2 & 3 to be at fault. Mates garage could not believe all three faulty at the same time. Took it to SEAT main dealers, more checks & diagnosed all three injectors could be faulty. Injectors taken out (diagnostics, labour & cost of sending injectors to specialist) & confirmed all three to be U/S. Originally quoted £300 per injector, now its £220 plus VAT. Bill at the moment is about £1100, car tax renewed today & insurance now also due. The 16V Cupra MOT was done in Feb, the Arosa had a new exhaust, also in Feb to get that through the MOT & the 1.8T MOT is now also due. Oh dear, expensive couple of months.

I feel for you mate, mine now has new tandem pump and 1 new injector and is still failing ! now told ECU, not sure what to do as the VW independant "specialist" still hasn't fixed it but i'm up to £760,Anyone know where i can get the ECU checked/repaired. ps my cupra leon is due a service, tax and 4 new tyres, deep joy

 

[CatB1]

Picked the Arosa up this morning after having all three injectors replaced, hope you guys have got your problems sorted.


Pete

 

[Bunkle]

Picked the Arosa up this morning after having all three injectors replaced, hope you guys have got your problems sorted.


Pete

afraid not, got in it today after being on hols for a week, started lovely drove like a pig, tried starting it after 30 minutes, turns over and over and over but will not start, aa man turned up filled it with easy start and i'm off again, i've had enough now, spose my last chance is an ecu test, anyone wanna buy it ?