Oil pressure

[Brojab]

I have a 2000cc 1984 spider and the issue is that it loses oil pressure after 10 minutes of driving then you would shut it off and wait 1 hour and it would be back to normal then slowly lose oil pressure. Anyone seen this before?

[Nut124]

What do you mean with loses oil pressure? Does the oil press light come on? Or just the gauge reading seems lower.

Oil pressure normally does drop a little as the oil heats up. The Fiat oil pressure sender/gauge are not very accurate.

What oil are you running?

[Brojab]

What do you mean with loses oil pressure? Does the oil press light come on? Or just the gauge reading seems lower.

Oil pressure normally does drop a little as the oil heats up. The Fiat oil pressure sender/gauge are not very accurate.

What oil are you running?

What do you mean with loses oil pressure? Does the oil press light come on? Or just the gauge reading seems lower.

Oil pressure normally does drop a little as the oil heats up. The Fiat oil pressure sender/gauge are not very accurate.

What oil are you running?

When I drive the car the oil pressure starts at 55 then goes all the way to 0 and eventually shuts off the car. All happens in less than 10 minutes. Also it is running really rich the spark plugs are burnt to a crisp. When I turn the car back on after an hour of cooling down it works again but does the same thing and shuts off.

[Nut124]

This sounds a bit strange to me.

Does the oil pressure warning light come on after 10min, before it shuts off? Is the light on when ignition is ON but engine is not running?

Does the engine quit in the middle of driving, or is this taking place while idling, stationary?

I was not aware that low oil pressure would shut down an engine, as a preventive measure.

Are the plugs totally black? Crisp to me would mean lean, hot, light colored plugs. Rich is black and sooty.

[Brojab]

This sounds a bit strange to me.

Does the oil pressure warning light come on after 10min, before it shuts off? Is the light on when ignition is ON but engine is not running?

Does the engine quit in the middle of driving, or is this taking place while idling, stationary?

I was not aware that low oil pressure would shut down an engine, as a preventive measure.

Are the plugs totally black? Crisp to me would mean lean, hot, light colored plugs. Rich is black and sooty.

Yes all the plugs are black and it’s running rich. I took the car in the meantime to a shop and they said I need a new ECM to make it work out but I cannot find any that would fit it

[18Fiatsandcounting]

I'm not as familiar with the later spiders, but I believe they shut off the fuel pump if the oil pressure dropped to zero (or very low). This was a safety feature in case the car was involved in an accident, so the fuel pump wouldn't continue to run if the engine stalled but the ignition was still on.

There are at least two causes for your oil pressure dropping:
1. Most likely. Your oil pressure sending unit is bad. Fairly common, and the one that controls the idiot light also controls the fuel pump (if my memory is right).

2. Less likely. Since your car is running rich, there is excess gas in the oil and it has very little viscosity left. Smell the oil and it should not smell like gas. Change the oil and the filter if you haven't recently, but you still need to fix the running rich issue.

Or it could be a combination of both.

-Bryan

[Brojab]

I'm not as familiar with the later spiders, but I believe they shut off the fuel pump if the oil pressure dropped to zero (or very low). This was a safety feature in case the car was involved in an accident, so the fuel pump wouldn't continue to run if the engine stalled but the ignition was still on.

There are at least two causes for your oil pressure dropping:
1. Most likely. Your oil pressure sending unit is bad. Fairly common, and the one that controls the idiot light also controls the fuel pump (if my memory is right).

2. Less likely. Since your car is running rich, there is excess gas in the oil and it has very little viscosity left. Smell the oil and it should not smell like gas. Change the oil and the filter if you haven't recently, but you still need to fix the running rich issue.

Or it could be a combination of both.

-Bryan

The car is not turning on anymore because the mechanic said the ecm is bad. Do you know where I can get a new one or possibly repair the one I have?

[18Fiatsandcounting]

I've seen ECUs (Electronic Control Unit) for sale on Ebay, or you can get a rebuilt one here:
https://autoricambi.us/remanufactured-bosch-ecu/

However, the ECU (same as ECM) is very reliable on Fiat spiders, and the issue is usually one or more of the many sensors that connect to the ECU. Or a bad wiring connection. My guess is that, if you replace the ECU, you'll still have the same problem.

If the starter motor cranks but the engine will not fire, there are a bunch of things that should be checked: check for spark, fuel pressure, air flow sensor, cold start injector (CSI), thermo time switch (TTS), coolant temperature sensor (CTS, the for the fuel injection system, not the one for the dash gauge), auxiliary air valve (AAV), proper voltage on the injectors, etc. Your mechanic should be familiar with all of these.

-Bryan