My pickup 91 Nissan doesn’t turn over at all sometimes. Battery is good, told it was the ignition but if I jump it it starts. Though if I use a Black and Decker 350 volt self jumper it doesn’t.
How do you know the battery is good?
Clean the posts & terminals really well and then make sure they are good and tight. Strip some insulation from the positive cable and look for any signs of corrosion. Auto parts stores will test batteries for free.
The battery has been tested. Posts are clean. I think maybe the starter is sticking.
It could be a problematic starter, but what happens each time you turn the ignition key? Do you hear any clicks, i.e., is the starter relay operating and determine whether the starter is getting power.
If you’re sure your battery has enough power and is putting out enough amps to energize the starter motor, then check the relay. If the starter engages every time someone uses a bump switch on that relay, then look back in the circuit towards either a bad ignition switch or wiring between the steering column and relay.
Using an ammeter at the hot side of starter, will tell you whether both the relay and the cabling to the starter motor are good when someone hits the ignition key. Then there’s always the “mallet test”. When it refuses to start, smack the starter with a large mallet and see if it cranks after that. Not too scientific, but it helps troubleshoot the starting system.