Stuck at the job

[Clay-Goose-Davis]

Just got off work and the car won’t start. No noise at all when I turn the key. Headlights turn on and battery voltage reads at 12.1. Service engine soon light is on when the key is turned but there’s no engine codes. 
I looked under the hood and found a broken line/hose. I’m not sure what this part is or if it’s the problem. 

Seems like the no start issue’d be a bad starter or fuse/relay. Any advise? And what is this in the picture 

[Clay-Goose-Davis]

91 btw

[rogold]

Have you checked your battery connections? Make sure they are good and tight.

 

[DAVES89]

4 hours ago, Clay-Goose-Davis said:

Just got off work and the car won’t start. No noise at all when I turn the key. Headlights turn on and battery voltage reads at 12.1. Service engine soon light is on when the key is turned but there’s no engine codes. 
I looked under the hood and found a broken line/hose. I’m not sure what this part is or if it’s the problem. 

Seems like the no start issue’d be a bad starter or fuse/relay. Any advise? And what is this in the picture 

That's the large diameter cruise hose.

If I was a betting man I would say either crank sensor or Ignition Module. I carry extras on both in the trunk.

[Clay-Goose-Davis]

3 hours ago, rogold said:

Have you checked your battery connections? Make sure they are good and tight.

 

Thank you for the suggestion. Yeah I did. I replaced the terminals recently too, due to stripped threads and a bad connection. 

[Clay-Goose-Davis]

2 hours ago, DAVES89 said:

That's the large diameter cruise hose.

If I was a betting man I would say either crank sensor …

Hey Dave, thanks for the reply.
What does the cruise hose connect to? 
and I’ll read up on the crank sensor and ignition module and act accordingly.

[DAVES89]

To the cruise control servo. 

[2seater]

Try a different VATS key? Neutral switch on the transaxle where the shift cable connects? Try starting with the shifter in neutral or while moving it around.

[Clay-Goose-Davis]

11 hours ago, 2seater said:

Try a different VATS key? Neutral switch on the transaxle where the shift cable connects? Try starting with the shifter in neutral or while moving it around.

I haven’t had another key made yet. I tried starting how you suggested with no luck.

[Ronnie]

Turn on the headlights and have someone watch to see if they go out when you try to start the engine.

[Clay-Goose-Davis]

17 minutes ago, Ronnie said:

Turn on the headlights and have someone watch to see if they go out when you try to start the engine.

Last night I could see the lights against the building. The headlights stay on. The dash goes off.

[Clay-Goose-Davis]

20 hours ago, Ronnie said:

Turn on the headlights and have someone watch to see if they go out when you try to start the engine.

If the headlights stay on that means it might be the starter motor or ignition switch right? Btw I couldn’t get the fan to turn on if that means anything. Thanks Ronnie

[Ronnie]

I was wanting you to do that because if the lights went out when you turned the key it would mean you had a bad connection to the battery. Since your lights don't dim or go out that tells me there is a problem in the circuit that activates the starter.  I hesitate to offer to much help on a '91 because there a lot of differences from earlier models and I've never worked on a '91. From what I've read here so far, your problem could be the theft deterrent system locking out the starter, a bad ignition switch or park/neutral safety switch as 2seater said.

 

Below is the path (yellow) the circuit takes if your '91  is like earlier models. Note the starter interrupt relay in the circuit. It is what keeps the starter from turning if the VATS is the reason it won't start. Assuming the '91 is same as other models, I  would do my troubleshooting at the transaxle position switch to determine if the starter is the problem or the other things mentioned. 

 

 

[Ohjai]

Here is the 91 Starter and Charging System.

 

A service manual is a an extremely valuable tool for these cars if you are going to do the work yourseld.

 

[Clay-Goose-Davis]

On 12/13/2023 at 9:22 PM, Ohjai said:

Here is the 91 Starter and Charging System.

 

A service manual is a an extremely valuable tool for these cars if you are going to do the work yourseld.

 

There’s a lot of E-manuals for sale and they don’t all look great. You or anyone have a recommendation?

[ship]

You might concentrate on acquiring the 1991 Riviera & Reatta Factory Service Manual.  I also recommend the 1986-1993 E Body Parts & Illustration Catalog.

[Clay-Goose-Davis]

Update-

Before I got advise from Ronnie,

I followed some of the troubleshooting guides on the ignition system and didn’t find anything wrong. I was going to troubleshoot the crankshaft position sensor next. I disconnected my plug wires first like the instructions said but then realized I didn’t have a socket big enough to fit the bolt on the crankshaft and called it a night. I also replaced my plug wires this summer and the new ones were not numbered so I left them disconnected until today. 
Today I looked up the firing order and reconnected the wires in the right order. I also read something about the security system possibly locking the starter and to lock and unlock both doors with the key to deactivate whatever lockout could be going on, so I did that after.

On my first try the car started with no hesitation. I let the engine reach temperature and took a lap around the parking lot, shut it off and sat for a second and started it again with no problem.

 

So something could be/have been wrong with the plug wires connection, or the security system.

 

With this new info, is their anything we haven’t considered that could have caused the no start condition ?

[Anthony]

You could completely remove both the crankshaft position sensor and the plug wires, and the engine would still turn over without any problem.

 

As Sherlock Holmes would say, once you've eliminated the impossible, whatever remains, however improbable it may be, must be the truth.