Hissing Sound Near Plenum

[joelittel]

Haven't checked for spark yet, working too much and haven't had time, but will as soon as I get the chance.

Checking for fuel seems easy enough, so I'll do that right after I check for spark.

No fire extinguisher in the garage, but I'll get one before I check for spark.

Thanks for all the advice

[joelittel]

Used my timing light to check for spark. There's no one here to help so the timing light method seemed practical. If this method isn't reliable let me know because I found that none of my spark plug wires would illuminate the timing light.

[narfire]

Ok , do you have an old spark plug to stick in a lead or well insulated screw driver and get it close to the valve covers for example.. Just confirm the no spark as one of my timing lights packed it in. Connections on the coil OK.
Still no spark , take the cap off the dist. and check the two thin wires. They get very brittle and eventually break. Sometimes the cap pinches them and again no spark. If they are pooched, then the pick up will have to be replaced.

Once you have spark, then you have to make sure it is at the right time....

[joelittel]

I'll try the spark plug method now. I'm using the distributorless ignition mark sells so I can't check any of the original distributor wires you mentioned.

[joelittel]

I found out why there was no spark, the sensor that kills the engine when it gets too hot was/is bad. Once I disconnected it and tried to start the car everything was back to normal, meaning the car sprang to life and in no time was purring like I'm used to hearing. It even sounded better than I remembered it sounding back in November when it was last running well.

It seemed very strange to me that my temp gauge would shoot right up to 190 as soon as I turned the key this morning so eventually I got around to trying to start the car without the two sensors connected. Guess I was lucky that nothing more serious had failed.

However, all is not 100% yet. My "Kill Sensor" (for a lack of better term) has rounded corners from me trying to take it out last year and therefor not easily removed. Can I safely drive the car without this sensor or do I need to find a solution asap? Plus there is still the issue of that hissing sound near my plenum. I've been reading a lot about the fuel system here on FS.com and it sounds to me like my fuel pump is turning on when the key is turned to the run position. It also sounds to me like some FI pumps are noisy in general, so I'll need to sort that out and get it set up the correct way.

I never did check for fuel once I determined that there was no spark so I'll still need to determine if my pump is "always on" or just noisy but not always "pumping."

Thanks to everyone who helped me solve the problem. I learned something new from all of you and hope some day I am in a position to help someone else.

In my efforts to solve this issue I came across a nice collection of FIAT Spider shop manuals and reference materials online. I have them all in PDF form and could email them to anyone who is interested. One of which is a 597 page Service Manual that covers things my Haynes or Brookland don't even come close to. PM or email me if you're interested, I'd be happy to share the wealth.

[majicwrench]

There is no "kill sensor".

Personally, not sure why you are worried about hissing noise.

Keith

[joelittel]

Hmmm. I thought I had read that one of those sensors was to shut the engine down if it got to be a certain, and dangerous, temp. Guess I need to read up on what it is I just unplugged...

The hissing noise bothers me because it's new.

Every year the car gets a little bit better than it was the year before, ( I clean, refresh, replace and rebuild the things I can and have a local mechanic do the things I'm not yet confident enough to bite off). I really like that it doesn't make squeaks, or rattle... it sounds "tight" like a car that's in great shape. You know how it sounds when you slap the side of your dog in praise, like a solid "Thud" vs. a hollow or weak whack, my car is like that thick muscular dog. When you close the door it sounds solid, when you start it up it sounds well sorted and athletic, bumpy roads don't make it chirp like some older cars do and I get a real kick out of keeping it that way.

This hiss/noise is simply new to me and that flips my OCD switch and gets under my skin a little bit. The simple fact that it's a new noise really makes me want to know exactly what it is.

Plus, if this noise/hiss leads me to discover that my fuel pump is running when it shouldn't be it's a win-win and I'll be very happy that I did put it on my "To Watch" list. If I can't figure out what it is right away I'll continue to monitor it until I do. I've found all sorts of fixable issues this way.

I get real satisfaction from the car fitting my special brand of "perfect."

Joe

[RRoller123]

The sensor you indicate just pegs the temp gauge, it doesn't shut down the engine. You have to do that manually, no automatic system.

[ORFORD2004]

If you want to know if your pump is running, turn the key on and check the voltage at the pump. (Under the car behind the driver seat)

[joelittel]

The sensor you indicate just pegs the temp gauge, it doesn't shut down the engine. You have to do that manually, no automatic system.

What does peg'n the temp gauge do? My car will not start with this sensor connected, and I can not get the sensor out to replace it. The corners are rounded (because of me) and the whole thing is seated extremely well at the moment.

When I first discovered that this thing was bad another member mentioned that he doesn't have his connected anymore and simply keeps an eye on his engine temp. Worst case, if my wife were to take the car for the day (and I'm guessing she never looks at the temp gauge) could I be setting us up for a breakdown by bypassing this sensor?

[RRoller123]

It doesn't normally do anything other than peg the gauge to tell you there is an overheating problem. Doesn't light up an idiot light or do anything else. It is likely a coincidence that the car won't start with it disconnected, unless there is some really wacky wiring flaw related to this.

[bradartigue]

Yes, like they say above, no sensor turns off the motor when its too hot. In fact except for a pulse from the ignition system and sharing a battery the FI system has no connection whatsoever to the car. Unlike today's motors that are tightly integrated the FI system is really just a big bolt on replacement for the carburetor.

There is a temperature sensor for the FI system and it is located near the radiator in the "T" in the front of the head, between the cam wheels. It has two connectors in a standard Bosch quick-release plug. If the plug or the wire to it are bad then the engine may not start. There is some debate on this but I can assure you on my three FI cars that if I wanted to kill the motor, I'd disconnect this thing. It is *not* a kill switch, just a temperature sensor that tells the ECU how to send fuel.

[RRoller123]

Agreed. Mine also won't run with the temp sensor disconnected (the FI sensor at the front of the engine between the cam wheels)

Pete

[joelittel]

I had the temp sensor you guys are talking about fail on me a couple years back. I also agree, if that sensor is unplugged or does not work the car will not start. I'm going to check out what I can this weekend.

I'm disappointed that the sensor on top of the head, between the plugs, is not the reason my car wouldn't start. But at this point I know I have fuel and spark.