My Saturn was running fine then after servicing A/C turned off & disconnected Freon gauges went to drive it cranked good but no start. It has no spark at coil terminals, no power to fuel relay trigger pin, fuel gauge stays at empty has about 1/2 tank of fuel.

I have changed the crankshaft position sensor, also checked continuity for ground at CPS connector but did not get a completed ground like u-tube video showed??
Fuel pump relay checks ok & if I jump the trigger circuit the pump starts but fuel gauge remains at 0.
I changed the engine temperature sensor.
I have checked all fuses several times, but using ohm meter checked the output terminals on under hood fuse holders I got a reading on all circuits except the EIS fuse holder. Not sure if I should have.
Have checked all grounds that I can find & all check with ohm meter & appear to be ok.
I’m trying to figure out what the fuel relay trigger, fuel gauge & ignition circuit/coils have in common, I’m thinking ignition switch but the starter cranks engine good.
I need a good diagram of ignition circuits, the ones I’ve seen on internet are not clear enough to really read.

 

Sounds like one of two things
1) the EIS fuse is blown. (Electronic Ignition System. )

2) The ckp sensor is flaking out or failed.

The CKP is not a powered sensor. The signal is generated by tracking the rotational motion of the crankshaft. Current pulses are generated in the ckp and are fed to the PCM. If the ckp fails, you will read an open resistance across it. The acceptable range is 500 to 700 ohms ish.

CKPs are known to fail intermittently, known to go open circuit only when hot, then contract and complete the circuit again(causing you to not know what the hell is going on when your car stalls when hot, will not restart when hot, but starts when cold.) And sometimes they just plain old fail.

For the record, if there is no CKP signal detected, the PCM inhibits spark and injectors.

What is the resistance reading across the ckp, disconnected from the harness?

 

The old cps showed 750 ohms, new one 850 ohms so was waste of time changing but had removed starter already for easier access so changed it out.
EIS fuse is good but how can I pull under hood fuse box to check pins on back of box?
Also do you think ignition switch could be the problem even though engine cranks ok?

 

Did you leak liquid refrigerant from the can at any point during the servicing?

Have you checked for fuel pressure at the rail after cranking?

Are you sure the harness to the ignition control module under the coils is firmly seated and corrosion free?

Does everything else on the dash function properly besides the fuel gauge? I know you cannot check the speedometer or the temperature gauge. When you crank the engine, does the tach move or sit at zero?

I'll go hit the schematics.....

 

Sorry. In the midst of a job search. You know how that goes.

Was hoping you would have responded to the questions in my previous post. Some of them seem silly and thoroughly unrelated, but often things are not as they appear in situations like this. So we go back to first principles.

Fuel air spark and compression.

I know you have issues with spark. What about fuel? Is there pressure at the rail? After cranking, can you smell fuel under the hood? Pull a plug. Is it gas fouled.?

Did you do anything besides add refrigerant? Anything that would have required you to disconnect wiring elsewhere?

I can't tell you the number of times I've worked on part a having disconnected module B and C only to fix a hookup C and forget B. And then wonder why it doesn't work.

 

I believe under hood junction box is held down by separate bolts in the center.

If you're going there, also pull the instrument panel junction box at the base of the center console. I believe there is a chance that a particular contact, F1 f2 F4 is a single distribution point for the fuel pump and presumably the sender, the dome light, the chime and some other stuff. Oh, the lighter. In those days that was a lighter not a 12 volt socket. People using high current cell phone chargers caused this particular pin to melt and devices attached to it with lose connection.

More likely than you should be under the hood in my opinion. Just a few bolts from one side.

 

Thanks will check the other pins in console, checked F5 cause it sounded like a trouble one but it was good & getting power thru it. I do get power to chime & dome light but looking for any possibility.

 

Sorry. I believe I now have a clue.

Lighter and radio and fuel pump all feed from F5 on second generation S cars.

Did you remove the entire fuse panel inside the car to inspect the PIN AND the mating socket.

​​​​​​Do your radio presets ever disappear?
It is possible that the pin itself can look fine but the socket maybe melted and vice versa. Usually you can see it on both. Here is a link to Richpin's video though I sense you have already seen it.

https://m.youtube.com/watch%3Fv%3DbE-HbjrIQSs

 

Sorry. I believe I now have a clue.

Lighter and radio and fuel pump all feed from F5 on second generation S cars.

Did you remove the entire fuse panel inside the car to inspect the PIN AND the mating socket.

​​​​​​Do your radio presets ever disappear?
It is possible that the pin itself can look fine but the socket maybe melted and vice versa. Usually you can see it on both. Here is a link to Richpin's video though I sense you have already seen it.

https://youtu.be/bE-HbjrIQSs