[TexasST184]

So I've been dealing with the dreaded problem of my celica deciding to not start whenever it doesn't want to. Idk if anyone else has tried the little ignition short circuit trick where you put a paperclip, or anything else metal for that matter, into the diagnostic port. That was working for me for a while but now that won't even work. Does anyone know the true underlying issue of this situation? I have a strong feeling its a grounding issue somewhere because it'll drain a battery if i leave it hooked up for more than a week without driving.

 

[sefiro]

Yep, have done it many times on many cars including my Celica.

The starter:

• is grounded through the transmission, thru the ground strap from transmission to left fender, thru ground strap from fender top to battery.
• primary wire from battery to starter
• control wire thru ignition, security, nss device, relay, etc to the solenoid on the starter.

Use a 6,8 gauge wire to jump the primary wire to the control wire to crank the engine. Be sure car is in neutral, parked. If key is turned on, the car will start and idle.

If the car does not crank, (starter not spin), then a ground strap, or primary wire is bad. You need to check for voltage at primary wire.

If it does crank, but you can't with the key, then you have to chase the control wire voltage thru the various points listed.

Btw - I'm in DFW area, you?

Sent from my Pixel 5 using Tapatalk

 

[User NameMarky C]

If the car starts when it is cold or not warmed up and then doesn't when it is warmed up or hot (like when you stop at the store and then get back in), it is one or both of the Battery Cables. When cold, there is enough voltage through the battery cable to energize the starter. When it is warmed up and restarted, the engine heat causes additional resistance in the battery cable to limit the voltage to the starter and not allow it to start.
There is a Relay in the Fuse Box by the Battery that allows the Fuel Pump to energize when you start the car. Sometimes the relay fails and maintains a connection to the Fuel Pump, which drains the Battery after you turn the car off.
This car is 30-years old and has been exposed to significant degradation. Also, there are wires on the Fuel Pump, which is submerged inside the Gas Tank. Over time, these wires become corroded and must be replaced. No matter what you find to be the actual problem, you should consider replacing the In-Tank Fuel Pump and attached wiring. Search YouTube for a video on this issue.