I'm really starting to struggle on this one. Fiat Punto 1.2 60SX – I4 engine, starting problems.

Engine will not start (turns over but not firing), has been missfiring for days, struggling to start, no power/missfire at low revs, poor idling, ran fine above 2500rpm, no missfire. At the moment it will not start, just turns over fine, but no firing, not even a little chuff.

Checked for spark on all 4 cyls, spark strong and regular. Changed HT leads, plugs and coils anyway. No signs of anything wrong on old spark plugs except a little covered in soot, but as I said been missfiring so to be expected.

Plugs are all wet and smell of petrol after trying to start, so suggests fuel is being delivered.

Headgasket was done in oct last year, no signs of HG going again – oil clear, rad water fine, no overheating.

Timing belt tension fine, doubt v much it's slipped as its a new ish belt, done with HG last oct.

Crank sensor may be faulty, but it's expensive to replace, and I'm worried about spending more and more cash on this car now.

Is there anything I haven't thought about? I'm assuming if spark, fuel & air are all getting to the engine, then it must be a timing issue, sparks not at the right time?

I am prone (like all mechanics/engineers I hope) to doing something really stupid, but I've been over everything and cannot find anything wrong. Petrol can+Match suggestions welcome, especially if particularly ingenious methods of dispatching the stubborn thing, at least I may be able to threaten it into starting! Thanks

Hi,

I think you need to hook a vacuum gauge up. This will rule loads of problems out, timing being one of them. Not that expensive to buy.

I would replace the crank sensor anyway. Is this the one with the sensor running off the cramkshaft pulley? I don't think they are that expensive – £45?

Hth
Marko

what year?

Yeah £45 for the crank sensor (on the pulley, you're right), but forked out £20 quid recently for oil+filter, £25 on plugs and leads and injector cleaner fluid, replaced vacuum tube to the injector, £45 on new coils, I've already spent a quarter of the total value of the car, and no change! Just a bit hesitant spending more with it being possible scrap.

Its a 1998 – R reg. mk 1.

1998 and you had the HG replaced last year?! How much did it cost?

Have you had the codes read?

I havn't had the codes read, its not a obd connector, some other type so can't do it with current kit I have. I guess that's probably the next step, where's good to get the cables from? Ebay or motorfactors?

I did the headgasket in Oct myself, got the head skimmed, had to get the thermostat mount helicoiled because it stripped when I put it back in. changed thermostat, belts, tensioner, gaskets, water pump, all the usual type stuff you do at the same time. Think it cost me £250 with the extras (helicoil because I was a pleb)

I had a problem like that on an old car and it turned out to be a damp distributer cap.

No dizzy I'm afraid, coils and ecu control the spark timing 🙁

Even if it is an easy fix I'd wax-up and sell.

Sorry I can't help on this particular problem though.

You've just re-awoken my Fiat nightmares of last year with our daugherts' diesel Punto. After many months of fixing almost weekly for various sensors and others bits failing it thankfully blew up and was scrapped. 😆

Honestly, sell it, buy something else at the sales cheap, Rover 25 1.4 springs to mind, ~300 quid for a good condition one.

I'm glad that others have had the 'experience' that is owning a Fiat…

I've changed the crank sensor now, found it at GSF for only £23 so worth a shot, still no change though. Got a jump from another vehicle to boost the starter, still nothing.

Currently I'm going to give up and cave in to getting a recovery truck to come and have a look, and tow me back if unfixable.

I'm off to uni in sept, was planning on SORNing it and leaving it at home until I need it for work next summer, but at this rate, will likely get rid.

Although it's had its problems, its a brill car for me. Only small hatchback of that age/price that will fit my family (4x 6 footers), and it will easily swallow multiple bikes in the back, and is frugal the way I drive it, 50mpg achievable regularly. And I like that its mostly mechanical and easy to work on, even if it does cause me issues like this!

Bolox, I've got an emotional attachment to a car!

i had something similar with an Audi I owned. It came down to the air mixure sensor being faulty. However it was fixed with having the battery off the car for 15mins or so. After that it worked fine for ages! It re-set the ECU which seemed to help things no end.

Worth a try?

Thanks for the suggestion!

I make a habit of disconnecting the battery when working around the engine bay, just incase I short/spook something, so the battery has been disconnected several times for over 20 mins (time required for ecu to reset), which results in the idle stepper motor resetting and positioning itself, and the ecu relearning a load of positions of bits. Unfortunately this has made no difference to it! But thanks for the idea.

Take a plug out, turn the engine over with your finger near the plug hole – can you feel any compression? Repeat for each cylinder.

If you think it could be a mis-timed spark thing, then check the distributor is bolted on tight. You can alter the timing by rotating it one way or the other. If it's come loose and slipped round, then that could be the cause. Get a timing light gun from Halfords/fleabay to be sure. One off cost, but it'll see you right for evermore.

Also, If you've got any kind of ingress downstream of the AFM (do Fiats have these?) then you're always going to have issues starting. Have you checked for pipes off, cracked pipes, etc.?

Its nearly always coils for a missfire and crank sensor for starting on these engines.

These are changed so is fuel getting into the bore?

motivforz – Member

Checked for spark on all 4 cyls, spark strong and regular. Changed HT leads, plugs and coils anyway.

Did you do this before or after it started refusing to go at all?

Could be something like a throttle position sensor, or the maf.

Ideally you want to borrow an identical car, and start swapping stuff over until you fix it!

Or buy my 850 estate off me.

Take a plug out, turn the engine over with your finger near the plug hole – can you feel any compression? Repeat for each cylinder.

christ who are you Mr Tickle!!

A mate had one of these. It would run like crap. Turned out it was the ECU.

It's a very common problem. New ECU fixed it…… for a while

sell it.

when it was misfiring was it missing on a particular cylinder(s) or was the misfiring spread across all four cylinders?
oher suggestions to add to the ones above could be engine coolant temp sensor or mass air flow either could be upsetting the mixture ???
Good luck

What about disconnecting the MAF? It should still start, if the MAF is reading wrong, could be overfuelling?

Ok then, thanks again for all the ideas.

As no cracked pipes as far as I can tell, the one cracked pipe (vacuum for something, cant remember what now) has been replaced.

Fuel is getting to the bores – wet plugs after turning over after airing the cylinders, and the throttle valve gets wet so injector is working.

I swapped the components over after it stopped completely, only thing I did before it died completely was put some injector cleaner in with a full tank of fuel.

New ECU is going to be around £150 to do myself, might have to be my next step, but trying to find cheaper options first.

As for the location of the missfire, don't know which cylinders it was, whether it was the same ones or not. Sometimes it was one cylinder, and sometimes it sounded like it was 2 cyls.

With the coolant temp sensor and mass air flow sensor, i understand they will change the amount of fuel going in, but would these really stop the engine from starting completely?

Thanks again for all these suggestions. Really appreciate the help, as it's starting to do my nut in. I hate being beaten, especially by a machine!

coolant tempsensor could cause overfuelling preventing it from starting.
mass air flow may cause some misfiring/lack of power but with both of these i would have thought you would hear the engine at least trying to start.
maybe go back to basics with compression check – it wont cost you to check it

Take it to someone who knows how to diagnose fiats with the correct tooling/knowledge before you end up doing what a lot of folk do on forums (even forums dedicated to the specific car model)

They waste their time and money. I had a running problem with my pug and so & so said to try this and that. some of them are well known tuners down south.. but i decided to take it to a well known pug garage and once checked, an injector was the problem. A 2nd hand one fitted from a recent break up of a similar model saw me leave the place a few hours later with £80-ish labour and 35 quid for parts. No buying half a dozen sensors from ebay/gsf etc.. just someone who can look at the car in the flesh and find out whats wrong first time round.save the ball ache and dont fall into that nasty money pit of hoping and gambling. Some folk will sound so convincing that this or that is the problem but it could be 1 of 20 problems.

ebay is your friend for ecu's,

are you getting a waveform from the crank sensor?

relays all ok?

you got a pickup on the key/immob problem?

simple tests, even if you think fuel might be getting through still might not be right, get someone to give it a squirt of bradex easy start into the mpi – if it fires then you have a fuel issue, check spark, not only that you have a spark, but also when it occurs, use a strobe or decent car multimeter. Those are both basic cheap checks…. You can also test the crank sensor with a multimeter whether it is hall effect or magnetic two pin type + air temp and water sensors – you can get resistance curves for air and water off web to ref want you see… Though after that it could be an immobiler fault in ecu. Unless you like fiddling, have tools etc, get a decent travelling mechanic to come round and take a look…… Or if you have recovery / breakdown phone them and tell them it does not start…

RECKON you got A immob problem, wire it out and try it.

Had a mate a couple of years ago who repaired the ecu's for these. He told me that it was just the earth track on the circuit board that blows. He simply solders in a new earth path.

Don't ask me how/where/difficulty/symptoms etc. No longer in contact either.

Have you been on any fiat forum to ask their advice?

I'm off to uni in sept, was planning on SORNing it and leaving it at home until I need it for work next summer, but at this rate, will likely get rid.

IMHE of trying to revive a car that had "sat" unused for a while – don't do this. They're just never the same.