So i recently bought a 91 s5 fc, when i bought the car the previous motor was blown and wouldn't start. Before i move on i want to clarify that my rotary exp is this car and this car only, but i have been a mechanic most of my life. That being said i thought i was capable of taking on the challenge of doing a direct swap with another s5 13b. I got the old motor out and the new motor in. But i cant seem to get the starter to engage and turn the motor over. Ive had the starter tested and even went as far as buying a new solenoid. Yet still when i attempt to start the car all i get is the popping sound of what i think is a relay. Ill be posting pics of my progress sometime today after i take the pictures, but i need to know if there are any high occurring problems with this harness/car/motor that would be causing this? I also need to know what the small gray denso box located on the drivers side behind the primary coil pack is cause the popping seem to be coming from there.

 

So when you turn the key, you hear a click, but the starter never spins? This sounds like the common starting problem many people run into. This thread addresses it: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/ive-solves-2nd-gen-sticky-starter-mystery-896013/. The OP and I devised a way to bypass much of the old stock wiring and supply more current to the starter solenoid. The click you're hearing is a relay pulling in, which is likely the box you're talking about as well. I think the main relay (next to the trailing coil) says Denso on it.

 

Thanks. Ive made some progress over the past couple days. I managed to get the car started which is a relief. I couldn't believe that an engine that sat for 3 years got some TLC and fired in three cranks. Prolly thanks to the refresher I did on the apex seals before we started it. I haven't fixed the harness problem yet but I've narrowed it to the blown starter cut relay, That and i need a new ignition bad. I started it with a wire to the signal post and then touched it to the power on the solenoid and it fired right up. I do need to know however if not having a washer in between a banjo fitting and the block can cause oil to come rushing out of the block, which happened to be the end result, so about 4 quartz of oil is now all over the driveway and I'm stumped on how it happened. It was on the drivers side of the block. thanks for the link to the other thread im going to go check that as respond back soon.

 

Yes, you need to have crush washers in there. There's no way the oil line will seal against the block without them. There are 2 needed per bolt.

 

Ok thank god that was the problem. I fixed that and now im on to the next one. i read what you had to say about a sticky starter and i need to know how to bypass the starter relay cause i believe mine is dead. How would i go about adjusting your fix to my prblem?