[Th3Tank79]

I have a 1998 Cadillac Seville STS
At tiimes turns over and fires right up
Other times it takes a good 5-6 times before it fires up...sometimes more
Been diagnosed to death at several shops...most places are at a loss...thinking its something in the electical system itself
when not starting it was seen that while cranking its not getting spark!

So far I've replaced both Crank sensors & cam sensor
ICM & coil packs
new battery...cables are good...strong connections
Throttle body & injectors have been cleaned

Newest development is that the dash lights will at times flicker or go out completely but still cranks

Has me thinking this could be the ignition switch itself because when I jiggle the key just right, everything comes on and it will eventually start

Has anyone had or heard of similar problems and found a solution?
its going in tomorrow to be checked again at Majestic auto, but I'd like to possibly recieve some input from other Cadillac owners & mechanics
thank you for looking

 

[Ranger]

Has me thinking this could be the ignition switch itself because when I jiggle the key just right, everything comes on and it will eventually start

Now there's a clue.

Just out of curiosity, have you pulled the DTCs and checked the fuel pressure?

 

[Th3Tank79]

Yes Fuel pressue was the first thing checked
and bad fuel pressure shouldnt cause the dash to flicker n flash lol
but the ignitin switch may not throw a code

 

[Ranger]

I understand that, but you could have had two separate problems. That's why I asked.

 

[Th3Tank79]

only code it throws is P0420....for the catalyst system bank one....
like an O2 sensor or problem in converter...but that all got replaced

brain box and grounds where checked as well...

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this is why it has me wondering if it could be due to a faulty ignition switch itself
or bad relay...

this model the ignition is all located behind the dash and I myself dont have the knowhow for that one and not willing to attempt it lol
just looking for some possible insight

 

[rodnok01]

There was a guy with similar problem here a few months ago, he had access to scope and if I remember correctly the ECM was bad or the wiring related to it. His problems were very similar. Might try a search for it.

 

[Th3Tank79]

Thank you for the input...
Will try to find that thread n see bout checking that out