Technical Tipo 1.6ie cuts out randomly (RPM sensors ? coil ? injector ?)

[Modano]

Hi all,
I have a '94 Tipo 1.6ie S, ECU is a Bosch Monomotronic MA 1.7 . (full electronic ignition / injection) - 205 000 kms.-
Regular maintenance is done. (timing belt, air filter, spark plugs).

Before last monday, only problem I had was that some mornings, the Tipo won't immediatly start, it takes 3 or 4 attemps. Sometimes, I unplug/plug the RPM sensors (although I know it has no effect... unless maybe electrostatic discharge ? or plug cleanup), and it works all the time (done several times). So, basically, I never had any problems starting my Tipo.

On last monday, My Tipo cut 4 times on the motorway....3 times at 120 km/h, followed by nearly immediate restart, and once at a lower speed/rpm.
I did the "RPM trick", and never had the problem on the return home.

As preventive actions, I did :
- Contact cleaning of the various Sensors (only air, water, RPM)
- Surface cleaning of the RPM sensor
- Change the fuel filter (50000 kms-4 yrs)
- Did a Multiecuscan : no problems on the Air/Water sensors, throttle position seems OK, lambda as well... No errors monitored, but unfortunately, no way to check RPM failures, as it always shows an error when engine is stopped.

My questions are :
- What do you think of this problem ?
- Do you think the RPM sensor (and/or its connector) maybe faulty ? How to test that, except by an oscilloscope ?...
- I'm afraid there is a deeper problem : the coil connector is greasy (all the engine is, anyway ), maybe the coil itself is starting to fail...
- or even the injector ?... (I used once Kent Fuel Gauge 2).

Thanks for your advices

 

[SpaceBird]

To exlude most simple solution; Did you check all ground cable wires from battery to car, intake manifold and possible gearbox to car body.
Check connector from ECU unit on the passenger side as also from your Digiplex ignition module (if your car has that?). If all ok, I think your flywheel sensor is faulty.

 

[dazzo666]

did you find the problem on this?

 

[Modano]

Hi,
sorry for the long delay.

So, for this problem.
Not sure it definitely went out, as random failures are, by nature, unpredictable. Anyway I did the following :

- Fuel filter change
- Multiecuscan Error reset (1 failure with the coolant sensor, maybe because I unplugged it engine running)
- Contact cleaner on the RPM sensor and secure fixation of the Coolant sensor (partly broken) + Contact cleaner as well
- Surface cleaning of the RPM sensor (shouldnt make any difference anyway)

And it never ever came again (around 10 000 kms done since). I gave the Tipo to my mother last month and will keep you informed

 

[Modano]

Oh and in 5 months run, I only had a difficult start once (!) instead of once every one or two weeks...
And I did a contact cleaning of the RPM sensor every two weeks for 3 months.

 

[bluejohn125]

I had maybe a similar problem with my late '94 1.4 ie - I think it got the same ECU setup as the 1.6 in its late development..

Sometimes it just would not start, I tried changing lots of things including the fuel pump, finally I had the AA rescue guy look at it and he found that a bad (water) temperature sensor with bad wiring / connector would stop the EFi delivering fuel.. I changed the sensor and wiring and everything became OK.

Maybe that was your problem...