Hi guys

Having a bit of trouble with my sisters car. Did a lot of searching here, but I would like your advice. The car is a 2002 1.2 8v 188A4000 with 160.000 miles (258.000km on the clock). Probably seen better days, needs its tappets done, but until now actually ran pretty great :spin:

Well, the main issue now is that it is not running right, misfire/not running on all cylinders I guess. Plus it vibrates and idles really rough.

My sister has only been driving it for about 2500 miles (4000km). When we first bought it, it had just had it's cam belt changed and I presume a headgasket replacement. Valve cover gasket is a little leaky as usual, havent gotten around to sorting that yet. It does not loose oil though, coolant is fine too.

I changed the sparkplugs and HT leads because they were old and crusty, and it ran fine (aside from tappets noise), until now. No power, rough idling and poor revving/power. It does drive, but barely, and the engine light comes on flashing almost instantly.

Thought it was the coil packs. I did change them, but it didnt help. But aren't the readings on the ohm-meter weird? Old VS new:

Old:

New:


Made a video of the car idling- http :// surl(dot)dk/huu/ (cheat link, I know sorry, cant post links yet. Maybe a moderator can verify it) Notice vibrations by alternator and motor mount.


Any ideas on where to go from here? Dont really know what to check. Although I am going to check the sparkplugs for cracks, didnt think about that yesterday. Probably gonna put a tester on it too, but I dont know how helpful that is going to be. I am really leaning towards a used engine, seeing that the tappets are also in need of repair. Dont know if the engine is worth spending a lot of time an energy on.

thing ive learnt about coil packs is this
1 - never buy cheap white box surprises, buy a quality replacement or oem
2 - when coil packs fail the resistance often is still within spec - which i found out when i had a pack fail
They tend to breakdown internally when hot but after a brief cool they work again


You need to disconnect the HT lead one cylinder at a time - find out which cylinder or cylinders arent firing
If you find 1 and 4 or 2 and 3 arent firing then were looking at a coil pack failure (from new) or a ecu failure or wiring fault

Puntos over here in the uk are prone to it... usually abused and never had spark plugs or ht leads changed, resistance builds up
Resistance = more amperage needed to charge the coil packs up = more heat = pop gpes the very find channels inside the ecu

If its a pair of cylindes 1/4 or 2/3
Swap coils over and see if the fault moves

If you have 1 cylinder missing
Start swappin a plug and see if the fault.moves
Again checking ht leads do same

Ive had ht leads fail also right out the box [emoji21]


If its a pair of cylinders down - and its not plugs/coils/leads

We need to test the signal the ecu is sending to the coils
The coils work on a negative switched feed

So power is applied all the time - however the negative side goes back to the ecu where it ""opens and closes" the flow of electricity

If the ecu isnt switching it on and off (stuck off) the we get the misfire

Ecu repairs are possible
Ecu swaps are possible (but require all the other electrical crap too)


Get back to us
Hope this helps

Ziggy


Sent from my SM-G920F using FIAT Forum mobile app

Hi Ziggy

Yeah well, granted I did buy the cheapest coils out there, hoping they would do it. But are they all dead, with those readings?

I did swap around the original coils, same problem.

Do I disconnect all plugs, plug in 1 cylinder, start the car and see if the cylinder fires, and then shut off and do next cylinder? Or disconnect them while running? Kinda noob here, I know


"Puntos over here in the uk are prone to it... usually abused and never had spark plugs or ht leads changed"
I think this is exactly the case here. Car does have a lot of maintenance receipts and papers though, but leads and plugs were awful. Tappets and valve cover gasket too


I ordered an old VAGcom KKL409 thing to use with MultiECUscan for Fiat, but the cable havent arrived yet. Might try a Delphi tester.

Ecu repairs are possible
Hm, is it expensive?

Ecu swaps are possible (but require all the other electrical crap too)
What other electrical crap? It isnt a direct swap? Saw a youtube video on how to swap ECU

Cant do anything with the car right now, but I will soon, thanks

You do NOT want to run around unplugging spark plugs with the engine running.. That's a bit dangerous..


You can get used, virginised ECU on ebay for 60£ or so.. Works fine - and then you don't have to get all the other "electrical crap" (which is body computer etc.).

I know its dangerous, thats why I am asking before electrocuting myself Although some people do it anyways (cant post links, BMACVAGS has a misfire video on the tube.)

Thanks for the tip on the ECU

Later today I am going to measure HT-lead resistance/continuity, diagnose the plugs (brand new Bosch FR8DC), check the coils again, and maybe have a look at the injectors as well.

Thank god for forums and Youtube

The injectors rarely fail on these engines - it's more likely to be an ignition failure, than injection failure.
If the car runs too long with this failure, the transmitter of the ECU will take damage (been there myself). Could also be low compression causing this.
Remember to check for fraying in the cables, revealing possible places where the spark may jump.

If it does prove to be injectors, I have plenty spare ones lying around.

The cables are new, have done maybe 1000km max, but I'll inspect them.

I suspect ignition, at least I hope. Dont really want to replace the ECU, but hey if there is no other option How long is "too long" ? It has only been idling a bit, and the occasional drive up and down the street to test.

If it does prove to be injectors, I have plenty spare ones lying around.
Great, I'll keep that in mind

Have you pulled the plugs to see if one is a bit different?
If you suspect an injector you could swap around it to see if the fault moves.

Brendan W said:

Have you pulled the plugs to see if one is a bit different?
If you suspect an injector you could swap around it to see if the fault moves.

Click to expand...

Not yet, but I am going to do that when I get off work today

Hmm, worked a little on the car today.. Found out that my plugs are not FR8DC but instead FR7DC+, is that a problem?

Measured the resistance in the HT leads, after watching the ChrisFix video (hehe). This is what I got, dont know if it is good or bad:

1 : 0.97k
2 : 0.84k
3 : 0.99k
4 : 0.70k

Ofcourse they differ in lenght, but I think the readings are a bit funny..

Oh yeah, btw, the fourth plug apparently was loose Did hope this was the culprit, but it wasnt. Still idles rough and misfires.


How do I determine whether it is the ECU failing? I think the next step will be putting a OBD tester on it.

Alrightythen, I'm BACK with an update! Finally recieved new sparkplugs and a KKL409.1 cable - damn holidays...

Well, I changed the plugs to NGKs (read somewhere in here, that they solved the problem for someone with a Panda). Did not help though, but now it has NGKs

Did manage to read out some error codes. P0300 and P0304, which is generic misfire, and specific misfire on cylinder 4, and I have narrowed it down to being injector 4 not getting the squirt-signal (if that is a technical term ).

Here is what I did:
- Ran the engine, pulled spark plug wire 4 - no change in idle
- Swapped injector 1 and 4, pulled spark plug wire 4, no change. Pulled spark plug wire 1, idle changed.
- Swapped connector 3 and 4 on the injectors, pulled spark plug wire 4, idle changed.

This tells me that the signal wire for injector 4 is bad somehow. How do I fix this? Is it ECU related, or a "simple" broken or loose wire?

Dammit, thought I was on to something.. Read somewhere on here that someone had a similar problem, where one of the injector connectors did not read ~2v when the car was in the on position. Measured mine, and they alle were around 2v, so I'm kinda stuck again.

Injector 1: 1.96v
Injector 2: 1.96v
Injector 3: 1.97v
Injector 4: 1.96v


Did a cold start, and heard it misfiring like this. Is it time for a replacement engine? And yes, the engine does rattle a lot, it needs it's tappets done (drives alrighty though, and that is the main goal right now, getting it back on the road), and I dont really wanna pour a lot of money into doing that, if the rest is garbage nor do I want to buy a new ECU if that isn't the problem either. It has done 258.000 KM.

Still really puzzled about this.. It's still down to injector 4 not getting a signal, but I dont know how to be certain that it IS the ECU. Still getting P300 and P304, so it's pretty isolated. Swapped injectors, plugs and coils around, no change. Used contact cleaner on all the plugs I could find, including ECU.

Did the testlight coil ECU check. Unplugged the coil that has cyl4 on i, started on the "good" coil with cylinder 2+3. Did get negative trigger flickering on the testlight, so the ECU is sending a coil signal. Both coils are new and good. Obviously could not start the car with coil 2+3 unplugged, and 1+4 plugged in, because cyl 4 did not fire.


Also did a compression test, since that's something that is often suggested.
Dry only though, didn't think a wet one was neccesary:


Cylinder 1: 225 psi
Cylinder 2: 190 psi
Cylinder 3: 225 psi
Cylinder 4: 225 psi


I am really close to getting rid of this awful barrow I dont really wanna spend more time nor money, when getting nowhere..

Can u redo the timing belt. It may be a timing issue.

could you please explain how you tested for the ecu earthing to produce the lt switching needed for ht to happen??

you know of the red neon plug caps that flash when ht passes thru them? but you may need to make 4 adaptors for them the reach the plugs??

Noids are available for injector signal testing, again ht neons maybe,or led's??

what would be the nature of the injector signals, how many volts??

check for a make and break contact inside an injector wire via continuity and wiggle test maybe??? maybe a load test may be needed also, wire size and number of strands dependent?

whats the compression ratio these and was compression test done hot or cold,or both.

clattery engine so valve working clearance check??? these use shims so camshaft out to replace/adjust?