Technical Help me bring my Punto back from the dead- Fiat can't!

[ricrea]

Hello Peeps,

Bought an 02 Punto last year (Mk2 sporting), ran like a dream, then head casket went. Got a new one done, £450.

Drove it away, but revved to high when idle. Small problem really i'd been driving it everywhere, took to another garage as original mechanic has gone, told me head had gone. Didn't beleive them. went to pick it up from a Fiat specialist that they had passed job on to - car was a wreck.

I believe it sounded as though firing on two cyclinders ie ECU/coil problem but at this time hadn't done any research so took back to the second garage. After 4 weeks of them playing with it bought a new engine from yard. Saw yard car, it was a write- off. Engine only done 27k so bought for £380 and let second garage fit it.

Now they tell me that the new engine needs a new ecu and keys barrel etc. (Fiat dealers Cambridge)

Looked on this great site and found info on how to change coils. Bought a pair and put on. Not much difference. Called AA-fault codes for fuel sensor came on only (P0460) but told this would not affect engine, this code was just for the display on dashboard hence allways showing low.

Now, I have the original ECU in car. Runs like 5hit but does start and stay running but only on two cylinders so no good obviously.

I have a new ECU I believe the second garage ordered but I think they tried this one without using the phonic wheel learn, could this have made it unusable or could this technique still be applied? Tried it but when I try to start it and push on gas does nothing unlike original ECU, so put original back in.

Also by using new ECU and my original 'probably' faulty ECU could I have damaged the new coils (only been in there for an hour)?

I have spent £1100 trying to get it sorted and it is worse than when I first brought it in, even with a new engine, but I am sure the problem is technical not mechanical.

I have lost my faith in Fiat dealers as all the official Fiat dealers tell me the same thing - to buy new parts as it 'MIGHT' fix it!!! - they told me that £1100's ago.

So I am going to give it a go myself and would really appreciate some advice.

Also one of you members with 55 thousand posts says an 02 MK2 Punto does not need now keys for a new ECU, but with a new engine is this MANDATORY? It still starts with my old key and sounds no different to what it did with the old engine I had the head done on. I think the garage thought a new engine would make things easier so they lied and said I needed one, hence not charging me any labour!

Please fellow Puntoians, don't let me lose faith

PS I don't know much about cars but am starting to learn so if I don't make sense my apologies

 

[ricrea]

I have been avidly searching this forum for months and found others who have had this problem and asked if they had it remedied to no avail so I thought id ask on here

 

[arc]

the engine is dumb, it does not need a new ECU or lockset when you replace it. You have been lied to.

afaik there was an issue with punto ECUs and the coil drivers, but i'm not too clued up on the specifics of it. got a feeling it was with the 8v models, but am not sure.

as you are relatively new to the oil bits of the car, have a read of this and get back to us

https://www.fiatforum.com/tech-talk/190268-basic-diagnostic-efi-petrol-engines-start-here.html

 

[richie.guy]

afaik there was an issue with punto ECUs and the coil drivers, but i'm not too clued up on the specifics of it. got a feeling it was with the 8v models, but am not sure.

It was the 8v's which had the issues.

 

[dave]

was the ecu the garage put on brand new?

 

[ricrea]

I think it was a new ECU yes, not from an old car I believe, but I'm sure he told me it cost £50 so sounds a bit cheap....

i will read up on that [arc] let me have a butchers

 

[ricrea]

I've been offered the ecu lockset and keys for £80 from the car yard (and car I got the engine from. Is it rocket science to install? I am very good at these types of things.

I might buy this as it's cheaper than an ECU.

If the ECU had failed would a fault code come up? There were only two related to dashboard electrics no coil or ECU faults came up.

I am currently studying arc's post as suggested. cheers!

 

[dave]

read this before wasting more money https://www.fiatforum.com/punto-guides/52068-punto-coil-ecu-checks.html

 

[ricrea]

Cheers Dave that was one of the first things I did but unfortunately I only tried this after I let the garage put new engine in, it didn't make much difference so I'm starting to think the ECU is at fault. It's just a shame that Fiat garages can't tell me the problem.

 

[ricrea]

Trying all the methods, but noticing coil plugs (new ones) getting very hot, still firing on 2 cylinders....i'll keep you informed

 

[tcook5]

I thought mine was running on two cylinders until i got a diag and one injector was gone and it screwed up the fuel/air mixture to the others.

Please try checking the resistance across the injectors, i wish i had and saved time and money.

If you cant do this whip out the plugs and report back on the colour of the electrodes.

 

[tcook5]

Also just read your original post and the new coils cant be damaged by the ECU. The ECU can only supply 12v at low ampeage and t coils can handle more than that.
Have you go te leads on the correct way round?
The cylinder order, of the coils, from the front of the engine is 3, 2, 1, 4
You need to get the pairs of coils to the correct pair of leads. if you get 1 & 4 mixed up it wont make any difference as wasted spark means the spark plugs fire twice, once on exhaust and once on compression.

 

[arc]

Also just read your original post and the new coils cant be damaged by the ECU. The ECU can only supply 12v at low ampeage and t coils can handle more than that.

Not strictly true. The power comes from a fused line to the main relay, the ECU grounds the coils to allow them to power up. A coil pack can be overheated and damaged by a damaged coil driver as it may be messing up the dwell time.

 

[ricrea]

I thought mine was running on two cylinders until i got a diag and one injector was gone and it screwed up the fuel/air mixture to the others.

Please try checking the resistance across the injectors, i wish i had and saved time and money.

If you cant do this whip out the plugs and report back on the colour of the electrodes.

I have had it diagnosed and there were no faults apart from temp sensor. Would a damaged ECU have a fault code?

I'm going to get my original ECU rebuilt at ECU-testing.com. as I have a spare one it will only cost me around 80 bucks (they buy them and discount rebuild).

Should I get new coils even though I just bought new ones? as when we tried a different ECU that we were unsure if was programmed to my car or not, the coils got hot.
I'd rather spend another 25 pounds than have to fork out for ANOTHER ECU.

I will check the injectors....and find out how it's done

Sorry I am so unknowledgeable but you guys are helping me learn, and it's not as though I haven't taken it to Fiat dealers ('official specialists....'), but over a thousand pounds later and a car that won't work iv'e give up on them. Anyway they told me my new engine needs a new ECU and keys etc so they lied. They did advise me that the ECU was :bang:'probably' faulty:bang:.

 

[richie.guy]

Not always, mine died without any code.

I would just use your existing new coils (if they are new?).

 

[ricrea]

cheers Richieguy. I got them about four days ago.

 

[ricrea]

Hi people,

Got my original ECU reprogrammed now engine is fine.
Had few faults, fuel level sensor light faults buzzing on driver side etc etc

Now got one problem,

The revs like to stick at 2000 and go up when idle.

Did a fault test and car says revs are at a ceratain level when car isn't even on. Going to get garage to look at unless anyone has any ideas....

Also reads needs phonic wheel learn but I can get the process to work as it wont drop down from 5000 rpm very well sticks at 3000, so need the rpm issue sorting.

Really quite happy this morning as I managed to fix 95% of the stuff the fiat garage in cambridge couldn't do or made worselast week I didn't even know what a spark plug was...

Once I have the car running well I will donate more to this site as it has been brilliant.

Oh just realised my air con (well heater thing ) doesn't work.

Laters

 

[arc]

heater doesn't work? as in, the fan - or no hot air comes out of it? If that is the case, it means there is massive airlock (bubble) in the cooling system. This is bad, and the cooling system needs to be correctly bled.

 

[ricrea]

The whole air con/heating system doesnt turn on, if i put it on any speed temp etc nothing happens as though it is not connected to anything.

Anyone have any ideas about the high revs? (See my last post) Cheers

 

[arc]

high revs could be an air leak (bad seal on the throttle body, inlet manifold or a pipe off somewhere) or the idle control (or throttle stepper if it's fly by wire throttle.. i can't remember if the mk2 16v is or isn't fbw).

i can't really advise any further as i'm not sure how the inlet on that car is set up (unless it's the same as the mk1 sporting, as that's what is fitted in my cinquecento!)