Before anyone mentions it, I *did* read through a lot of forums related to the RX-8 not starting.

My car: 2005 RX8 MT @99k miles
This is a project car... we just wrapped up the following-

Did a complete engine bay swap with a JDM engine. All engine bay components are relatively new (JDM engine came with trans and components, ~45,000 miles). Engine was tested before being shipped out, listed at a 90ish psi. (I apologize for not knowing more about how compression tests are rated.)

We also replaced coils, plugs, and wires. SOHN adapter was installed.

Day 1: After fixing everything my friend made the mistake of starting it with the JDM ECU. This tripped the immobilizer system and unfortunately the car was towed to the stealership... 2 new keys later, she runs! () I get pretty excited... we drive it to a gas station (drove fine for about 7 minutes) then filled it up. Car doesn't start, or doesn't seem to want to start. We attempt a quick deflooding procedure and the car starts up again.

Day 2: We decide to tackle the easy things:
Battery: tests good
Wires/Terminals: good or cleaned
Starter(we had the old 100k mile starter in, replaced with the same type JDM starter):check
Grounds: check


Car starts up fine; we decide to head over to Costco to install some tires. Luckily, my friend was trailing in my other car- the RX8 was dying on idle. (This issue was only happening on day 2). He pushes us forward so we can start the car, and we head back home. Once home the car still doesn't want to turn over/start (just cranks). In trouble shooting, (spark plugs are dry, we don't think it's flooded) we hook two batteries up to the car and it starts after cranking for about 3-4 seconds.

We drive the car for a good 30 minutes, low and high revs. We park the car in the garage, STILL won't start.



I'm pretty much at wit's end... I love this car to death and I've only had it (driving) 3 days. Tomorrow I will try a cold start (since it's possible that warm starts are the issue.) If it still doesn't start, I'm going to buy a better starter. Thoughts? Am I totally fucked with this engine? I really appreciate any responses or help I get on here, thanks guys.


This is when the car started up(two batteries) , I cut the video off because I didn't think it would. We tried two batteries later, didn't work.

 

The first thing to know is : you can start a renesis with less than half the compression it came with new . I know this very well as I've had to do it for about 2 years on a completely stuffed engine . It took a while to crank over but I ALWAYS got it going .

The second thing you must find out is ...what actually is the compression as if one or more chambers is down to zero ...there is no sense flogging a completely dead horse . (mine was still twitching)

Armed with this knowledge you can go forth and do what is required to make a tired engine start .
1/Good strong Battery
2/Good connections on battery /starter motor /earth.
3/Good starting speed .... 250rpm or better (pre 2005 low voltage starter motors don't cut it in any condition)
4/Good ignition . Get yourself an HEI coil tester (they are cheap as) and make sure they all pass.
5/Good plugs

Aside from that there are other issues that can prevent starting ,but the fact that you actually got it started a few times makes me tend to think you can attend to the list above and be golden.

 

Thanks for the reply Brettus-

Thursday I'm going to check the fuel lines... car was sitting about 3 months before I bought it. Also going to check the battery again and get a better starter (this one is a 2005). Wish me luck, I'll keep the thread updated :D

 

If I were you, I would have it compression tested with a rotary-specific compression tester. There is no point in throwing more money at a bad engine.

 

One more question- could rust or the fact that the car was sitting for 3-4 months with 1/5 tank of gas caused some sort of fuel related issue? Either the pump, or possibly the fuel filter is clogged? It almost sounds like it's not getting enough gas, and when it does start it sounds... Hesitant?

Still heading up to work on it tomorrow. Wish me luck!

 

3-4months isn't that long really ........ but sure , it could be related to fuel supply.

I'm leaning towards ignition and compression though.

 

Keep us posted with the compression numbers, I've wondered about the mileage/health claims of those JDM import engines.

In an unrelated matter, it looks like the undertray is not installed on your car in the video you posted. I'd have to imagine that you simply took it off given the scope of work but make sure you get that back on before driving once you fix the starting issue. Don't want to see one problem turn into a cooling issue.

 

Starting to think it's the ignition, going to swap the old coils back in/test the ones I have rn.

Replaced the starter/battery, and the fuel pump while I was at it. Confirmed that the fuel pump was working, and the car turns super fast now.

Kinda concerning- when we tried to push start the car, the car idles till it loses momentum (so it's turning/you can hear the exhaust) but if I try to give it gas, I don't get any response.

Not gunna lie, pretty bummed. Even got a speeding ticket coasting 38 down a 30 in my own neighborhood by the friendly police officer. Help me out guys!

P.S. I'll post another update in a bit regarding the coils

 

Will it start with a small shot of oil administered via the vacuum ports? (via syringe)

 

Can you advise me on which vacuum ports, or where they're located?

 

Final update:

Tomorrow morning I'll swap the coils and see if it makes a difference. If not, I'll just have to spend the money to tow it to the dealer.

Pretty frustrated, but not too sure what else I can try. The thing I really don't understand is I can push the car, drop the clutch, and it turns on.... But I can't give it gas after that point.

 

There are two vacuum ports on the lower intake manifold. If you follow the intake runner from where the plastic manifold meets the aluminum manifold and follow it down a little ways you should see them. They should have caps on them. If you take the caps off you can squirt *little* oil into each side, replace the caps and it should help it start. It's not the way it should be done, but in a pinch it works. In your case I don't think it will matter. Sounds like you have other problems. I would guess a big vacuum leak or an electrical related issue if it won't stay on it's feet. Sorry to hear your going through this......at this juncture Willie Nelsons song, "Bubbles In My Beer" comes to mind. Hang in there......