Fiat Punto1.2 8V Dynamic 53 plate,
Hi Guys,Sorry about the long post but I want to give you as much info as possible. My daughter bought her Punto in late July, this is the first car she has owned. We fitted new plugs, HT leads & air filter and checked oil.
Everything was going fine until the day before the bank holiday Monday when the MIL light came on & on the Monday when she went to work & the car failed to start.The engine burbles like it wants to fire then dies on first crank & it will not fire after that. Checked we had a good spark-OK, crank sensor Ohms –OK & various wiggle tests. Added some petrol thinking perhaps gauge was faulty, (showing ¾) car started 3rd crank, filled up with less than ¼ tank used at petrol station so gauge wasreading OK. EBOD test was carried out to find: 2 DTC’s P0351 & P0352 – coils. The MIL light has gone off after a while andwas put down to loose connections as coil circuits tested and Ohms within spec.
Happened again about a week later. Removed petrol cap thinking pressure problem after above. Car started 3rd crank.
OK for a few days, then car wouldn’t start at all. Engine turns over fast; checked spark at plugs -yes, fuel pump heard working-yes, and fuel at pressure release valve next to fuel rail-yes. Called RAC & guy reset the fault codes above & car started first crank.
Driven Home approx.5 miles failed to start next day, Monday. Reset fault codes drove car to garage that night. The garage at first thought it was the immobiliser, so called an auto electrician to get to the bottom of the problem. He changed the T09 relay saying it was burnt out. The car was kept at the garage the rest of the week and started at regular intervals no problem. Brought it home Friday, drove It to Reading Uni. from London on Saturday. Daughter says it ran like a dream, no problems with lack of power, misfiring or overheating. She drove to work that evening and back again at 2 in the morning. No problem. Went to pick house mate up from the station yesterday –wouldn’t start
Called the RAC again. This guy happened to be an ex-Fiat mechanic who said he knew Punto’s. He went through the motions and suspecting the ECU. Swapped that & the camshaft sensor for known good ones he carries out of habit with him. Still wouldn’t start. He was baffled. Did some wiggling, car started although he admitted he couldn’t remember exactly which bit he was wiggling before it started. Swopped everything back again, still working. Nice guy that he is said he has a pair of new coils in his garage which he would drop off FOC as he doesn’t need them. Will wait to see if it happens or not. I will buy a set regardless.
Seeing as new ECU & camshaft sensor didn’t cure the problem, can anyone give me some guidance on where to start looking after we fit the new coils? My thoughts are this won’t cure the problem as the Ohms measured fine, but may lie with the engine temp sensor on the throttle body as this only happens when cold.


Any Ideas anyone?
Roman

IIRC T09 is the fuel pump relay. Maybe the sparky fixed a symptom but not the cause. When you turn the ignition on you should hear the fuel pump hum for a bit as it primes the system.
I recall someone finding a loose ecu earth wire on the inlet manifold throttle body under the air filter which when secured fixed a T09 clicking and no start problem.
I'm sure I've seen this issue here more than once so search T09 might produce some interesting stuff.
If you do open the ecu earth wire to clean it I would disconnect the battery first and let the car sit for 10 minutes or so to avoid the possibility of triggering an srs alarm.

Thanks for the info. I've a circuit diagram from this forum and have it front of me as I write this & I can see that T09 (K46) also activates the injectors & the coils but does route through the ECU on the negative side of the coil.


The fuel pump can be heard to be whizzing around when the key is turned and although I haven't done a pressure test there is fuel in the fuel rail under pressure so I don't suspect a pump problem.


The earth lead you mention was checked & cleaned just recently as part of the various inspections so I know this to be good.


Roman

Does the pump cut out after a few seconds running?

Yep,


The pump primes for about 5 seconds then goes quiet until you start the engine.




Roman

Never trust a coil pack to be okay
Pure and simply because it checks out to be ""resistively" okay

Its okay when its not under load - so the resistance is fine
but under load its not able to cope and it breaks free

The punto is well known for coils, they can be fine 1 day, and dead the next

I had that myself, went to derby car drove fine ALL the way there
Got in the car to drive home went to mc d's on route - it was fine

After leaving Mc D's, i got lacking power with the EML on.... the car started to limp

Yet 4hours before it was PERFECTLY fine

They both also tested out to be "resistively okay"

Ziggy

Thanks Ziggy,


I am hoping the RAC guy is as good as his word and drops of the surplus coils today otherwise I've another 140 mile round trip ahead of me. I should have changed these when the problem first reared it's ugly head but I got side tracked into thinking it was something else. Any way they'll get changed this weekend regardless and we'll see after that.

Car's running OK-ish at the moment I'm told

Roman

Roman1963 said:

Thanks Ziggy,


I am hoping the RAC guy is as good as his word and drops of the surplus coils today otherwise I've another 140 mile round trip ahead of me. I should have changed these when the problem first reared it's ugly head but I got side tracked into thinking it was something else. Any way they'll get changed this weekend regardless and we'll see after that.

Car's running OK-ish at the moment I'm told

Roman

Click to expand...

my coils jumped from been okay to dead
Once cooled they were fine again, but would suddenly cut out again

Dont go white boxed parts shop special - get genuine or high quality items Such as NKG or Bosch or Magnetelli etc

Ziggy

I never buy shady makes if I can help it. I learnt my lesson long ago with a suspect fuel pump for a Fiesta which leaked everywhere. Eurocarparts have Magnetti's on offer online for £28 each. They are around the corner from where I work so I can click & collect at lunch time.

Roman

Just a quick update.


Since the RAC man got the moody Italian running last Sunday it hasn't had a recurrence of the starting problem. My daughter has used it every day since, sometimes several times a day. It was running rough on Monday but by today (Thursday) has settled down again. I suspect the ECU needed to be updated with info from the sensors to adjust the settings correctly over a couple of runs. The MIL light also went out by itself on Tuesday and hasn't come back.


I'm going to fit the new coils regardless tomorrow as the only fault codes we had were coil related and also go through the connections and earth points to make sure they are clean and tight.


I'll update as I have any news.


Roman

Quick update,

Changed both coils on Luigi (as he is now called) on Friday. Starting is noticeably better,almost first turn of the key. The old coils were a miss-matched pair, one Champion & one Magnetti M. Both looked in a very sorry state externally.

MIL light came back on immediately same codes P0351 & P0352 - coils! Urgh!!! It’s been on all weekend as well, where as before it’s gone off after a day or so. I suspect that this time it’s the difference in resistance between old & new coils that the ECU is picking up as we didn’t clear the fault codes. Also the car hasn’t done any serious mileage since Friday just a couple of miles to work & back. It’s due to go for a run to Swindon & back to Reading so I’ll have my girl clear the fault codes this week, which I hope will allow the sensors to reset properly.

Other than that no issues to report. Not a hint of the non-starting we had before so far, but early days. I won’t be happy until it’s done several weeks trouble free.


Roman

The Ecu might be funny but it should very very quickly readjust

Make sure all DTC's are clear incase any new issues arrise

But as long as the coils - ht's and plugs are all okay
Then keep motoring

Make sure you stick to the replacement schedule as the ecu is prone to backfeed and burning the driver tracks out - resulting in a costly repair

Ziggy

Ziggy,


Thanks for the advice, it is pretty much our plan.


If anything changes I'll post an update.


Roman

I've spoke to soon,

Call from my daughter - car won't start.


She cleared the fault codes with the app on her IPhone and it started again first turn although lumpy until it re-sets. Interestingly only 1 DTC showing for "primary coil A" (P0351). She is going to give it a run out to settle it down and report back. At least the app on her phone gives her a chance of staring the car when it fails.


If we hadn't already tried swapping the ECU I'd be inclined to say that's where the problem lies and get it replaced but I'm thinking there's another something else going on.


Which coils is "A" right or left?

Roman

Dis connect one and make it develop a t DTC, so you know which one is which

I'd be quiet enclined to say - its a wiring fault
Since the ECU has been done along with the rest of the ignition system, i'd say either there is a damaged wire or the new ECU is still fu....


Ziggy

I have to confirm with the mechanic ( if I can get hold of him) if he replaced the original ECU as the "spare" one he swapped it with didn't seem work at the time. I can't believe he left the new one on TBH. In which case perhaps the original fault is still there but with new coil packs


I have been reading on the net about a known problem with the loom in the shielded portion that runs over the cam cover, I believe where the connectors for the fuel injectors emerge. I wonder if anyone else has heard of this? It was on the BBA-Reman web site.


http://www.bba-reman.com/content.aspx?content=Fiat_Punto_Technical_Help

Looks like another 140 mile round trip coming up.

The things we do for our kids.

Latest news.

The car now won’t start even when the fault codes are cleared. I’m of the opinion that the ECU is fried completely unless there is one very bad connection that makes & breaks.
We are also pretty certain that the ECU is the original one that was fitted to the car before the RAC man played around with itand got it going nearly 2 weeks ago.

I have some good quotes from a couple companies to repair the ECU but I think for speed I will have to use ecutesting.com they have an ECU on ebay for £120 on exchange. Has anybody any experience using them?


Roman

Quick Update,

Looks like the curse of the bad coils spiking the ecu again. I checking every connection in the ignition/fuel injection circuits for continuity from fuse board back to the ECU connectors which confirmed all were sound. I did mean to take some photos to do a guide on fault finding/circuit testing but the weather was that bad I had to give up.

Fitted new Magnetti coils last week & the ECU from which arrived Friday from ECUtesting.com. Despite having a flat battery Luigi started first turn when a donor battery was connected. Set up the ECU and went for a long run. Everything seems Kosher so far. My girl has been tasked with doing lots of short journeys to force any issues that might be hidden but so far so good.

Big shout to ECUtesting.com. Despatched the same day they received the order, kept me informed all the way, very helpful with any questions I had too plus free P&P even to return the old ECU.

Here's hoping that's the last of the starting problems.

Roman