Spark no start

[72fiat850]

Hope someone can help me Drove the car last weekend for about 1 hour ran great, stopped to get my paper and car stalled. Would not start back up. Had to push it into my garage. here's what I have so far. Car will crank, but not start. Getting a spark, tested coil resistance is with-in specs, but only 6-8 volts when cranking. Fuel pressure is also fine. Crawled under dash, found a burnt out fuse? but no change. Ignition switch wires look good, no burning or apparent issues. Hate to start just buying parts, but do you think it could simply be the coil? I have a decent basic understanding of these cars, but am really only a weekend mechanic.

[seabeelt]

As our good mentor Brad says, test, test. As Magicwrench says, don't guess. First is battery fully charged after all the cranking. Second, if you pull a plug and are getting spark, that more or less eliminates ignition troubles. That leaves fuel. With the air breather off, if you depress the throttle, does fuel squirt into the carb?. If you pull the fuel line to the carb and crank, does fuel come out of the hose? Do you have any fuel line leaks preventing fuel from getting to the carb? Are you sure there is gas in the tank? What about the fuel filter? Do you have one, when was the last time it was changed?

Report back and we can go from there

[72fiat850]

first thanks for the reply
I should have said it's a 1981 2000 With FI
yes battery fully charged
yes pulled plug spark
yes good fuel pressure -- pump on with key-- I think PO bypassed a relay but that's a job for a different day
clean filter drained and cleaned tank last fall new filter at that time only a Summer driver

Spark + fuel should = running
the frustrating thing is I know I'm just missing something. I miss my old 1972--850 just a basic engine that anyone could tear apart and put back together-- I even replaced a head gasket in the parking lot of a nearby school

thanks for any help

[spider2081]

A common problem is the temperature sensor in the coolant "T". The connector could be intermittent and or the sensor bad. resistance between the pins of the sensor should be around 2000-3000 ohms at 70 degrees F.
Also any air leak between the Air Flow Sensor could keep car from starting.
And the cold start valve connections should be checked

[72fiat850]

Thanks my son did mention it ran rough and stalled a week or so ago when the engine was hot can I bypass it to test it

[spider2081]

If you have a volt/ohm meter measure the resistance between the pins. Then clean the pins and connector pins. Hold pressure on the plug as you try to start the car. ( takes 2 people)

[majicwrench]

I would not recomment just randomly cleaning connectors unless you know something is wrong. You will end up creating more issues.

Did you pull a plug?? Is it wet or dry?? If dry, I would take a hose off, like vacuum brake hose, and piss a small amount of fuel in, tablespoon or two. Does car now fire and run??

[wizard124]

The Fiat FI Diagnosis manual I have says this for a "Cranking, but no start condition".
1) Check for spark;
2) Check for air leaks;
3) Check fuel feed pressure. Disconnect vacuum line from fuel pressure regulator. Connect a gauge. Operate starter and you should have 35.25 psi in the fuel rail. There is more troubleshooting if not in spec, so let me know
4) Check for voltage at the injectors. Test light should have weak and flickering intensity;
5) Check Coolant Temp Sensor Resistance. 2100 to 2900 ohms at 68F:

It gets more involved after this. The double relay also supplies voltage to the ECU, injectors. If the wiring is bad or this relay is faulty, the Injectors won't pulse