Tuning Stalling

[rogerowen]

Took my 2000 Seicento for MOT, failed on emissions - said it overheated in 2nd attempt, fan seized. Anyway, now the car starts, runs but after de-acceleration - stalls (unless I can get my foot onto the throttle pedal in time to rev). Does this point to some kind of sensor or ECU problem??

 

[Pep0]

Hi

Is it MPI or SPI?
Does it stall hot or cold or both?
Does it misfire for a few seconds starting in mornings?

 

[rogerowen]

Is it MPI or [COLOR=#f77e1d !important][FONT=inherit !important][COLOR=#F77E1D ! important][FONT=inherit ! important]SPI[/FONT][/FONT][/COLOR][/COLOR]? ---------Not sure, it's 899cc if that's the difference.
Does it stall hot or cold or both? ------------ both, but worse when hot.
Does it misfire for a few seconds starting in mornings?........... No miss-fire, but engine starts with high revs for a few seconds, then slows.

 

[fingers99]

If it's 899, it's SPI (Single Point Injection = one injector).

If the MOT man says the fan seized, then that's where I'd look first! (The MOT man is not God incarnate, but chances are he knows more than you.)

Ignition off, fan connector unplugged, try turning the fan by hand. It must turn easily.

Get back with the fail sheet.

It's unlikely to be the ECU -- the SPI ones are almost indestructible.

 

[rogerowen]

Thanks, I'll give that a try. I got the fan rotating by hand - but I guess there's no way of checking that it's working ok till the engine gets really hot. I have heard the fan cutting in before in slow traffic conditions

 

[Pep0]

The thermostat switch is on the rad plastic between the inlet and outlet hoses.

Unplug the electrical connector there is a latch you need to lift first otherwise not much force needed and stick a bent paper clip between the two pins in the cable end.

The fan needs to be free to spin so check that first again.

If it does not spin freely try dose of WD 40 spray at shaft bearing if it is not free it will burn the motor out.

How long have you had auto and does it have a maintenance history?

 

[fingers99]

Try pulling the fan connector and applying 12v (+ and -) directly to the fan side of the connector.

I did a debugging guide to the SPI fan system for Cento Rebels, but the site seems to have gone down, so


This applies to SPI Centos. It should apply to Mk1 Puntos, too. On MPI cars the fan is operated by the ECU.

This attempts to present a logical way of troubleshooting a non-functioning fan. Bear with me!

The important thing to remember is that the fan is permanently live and is switched, by the thermo-switch on the radiator, on the earth side.

First, check the fuse. On the SPI Cinq no. 3 (25amp) in the main fusebox (passenger compartment) on the SPI Sei it's a 30amp maxi fuse behind the battery, there should be a fan symbol on the cover (check, though -- someone may have put the cover on the wrong way round!).

Next, try bridging the switch contacts (on the rad, right hand side as you face the engine) with something. If the fan goes, try bridging with a paper clip. If the clip glows red, the fan is drawing too much current and needs replacing (visit the scrappy). You might consider buying a new one from FIAT, but better quality (and thinner) fan/motor assemblies are available from after market suppliers, although fitting will entail a little DIY.

If the fan doesn't work, disconnect the connector to the fan itself, and put 12v (+ and -) to the fan motor directly.

If the fan works, put a meter to each of the contacts to the fan in turn (the other probe to earth). One should show 12v, the other nothing. If you don't get 12v, the live side is faulty.

If the fan works and you get 12v, the fault must be on the negative side. This will almost certainly be nothing more than a bad earth, so, attach a supplementary earth to the earth terminal on the offside wing, use the other end to probe the contacts on the radiator switch contacts in turn. One should cause the fan to run: you want to connect the wire to the other one (rather, to the wire going to it).


Diagram for Cinq, but it's pretty much identical for the SPI Sei.

 

[rogerowen]

Good tip, thanks - I'll give that a whirl. Not sure if this is significant, but I've found a narrow bore rubber pipe (with an in-line double cone plastic box - Flame Trap?) -that runs from the base of the throttle block to the back part of the ECU. It's quite perished and I may have disturbed it when I took the spark plugs out for inspection and cleaning. Think it might be worth replacing this pipe - even if it's not the cause of my stalling problem. Will report back if it works!

Had the car for about 10 months, only £350, and it's been a really good little car. Nothing much in rthe history apart from tyres, battery, exhaust - that sort of thing. I've just replaced one inner drive shaft boot, as oil was pouring out through the race that sits on the shaft. Got a good guide from this site and I have some extra info to add when I get a mo.

MOT man pointed out that things were pretty rusty underneath - particularly the rear suspension gear - I intend to borrow a 4 post lift and spend a weekend cleaning de-rusting and painting

 

[fingers99]

Good idea -- lots and lots of GT 85 on the nuts and bolts every day for a week before you start.

 

[Pep0]

Yes replace both hose runs leave the lump in middle in place. An air leak would cause problems.

 

[rogerowen]

Stalling problem solved! It was indeed the splits in the small rubber pipe that runs from the base of the throttle block via a (flame-trap?) to a small appendage at the rear of the ECU. Just one corroded brake pipe to replace and get the parking brake a bit better and finger crossed for a re-test.

 

[fingers99]

Probably the MAP sensor pipe.

But good stuff.

 

[blu73]

I did a debugging guide to the SPI fan system for Cento Rebels, but the site seems to have gone down, so

It my understanding that they have closed cento-rebels fella. It is kaput forever.

 

[fingers99]

It my understanding that they have closed cento-rebels fella. It is kaput forever.

Yes. Looks like even the domain name is up for grabs.

 

[blu73]

yeah i saw something about it on facebook. to be fair, sandy hasn't had a cento in years now and don't think anyone was prepared to take the site and its costs over.