Rebuild my RX8 13b Engine, but doesn't start? (Solved)
 

Hi all

I need some help, my apex seal broke and i decided to rebuild the engine, also bought a new front rotor housing because it was damaged, the same one with the broken apex seal.

Me and my Dad is doing the rebuild, he is a mechanic

Started the rebuild everything was going good until today, when we wanted to start it. We then push started it, it start but sounded little loud like one of the spark plugs where not firing and had no power also didn't idle and keeps fluding http://rx8ownersclub.co.uk/forum/ima...s/eusa_doh.gif

So thinking it was the spark plugs or coils, we tested the coils, all was working, testing the plugs, found a dead one, replaced it.

Compression is there and she starts up idle for +-10 sec and then she starts loosing rpm's and dies

Did we put the rotors in wrong? we put the back rotor 12 o'clocke and the front rotor 6 o'clock
Can it be the timing? The Eccentric shaft position plate?

At the oxgen censor near the transmission there are 2 white plugs and 2 black plugs, i put white in white connectors and black in black connectors, does it matter if i there are swaped?

Please ask me if anyone needs more details

Ty for Helping

Here is the picture from the manual we used on the rebuild:

http://s16.postimage.org/ugz1n4bqt/Rx8.jpg

Did you try the brake stomp method to reset the ECU?

Hi Arca

Yes did that yesterday, Ignition on but not start, pump brake pedal fast, oil needel went up and down.

She started idle and died shortly after again,

You just say the compression is fine but did you actually test it? what are the numbers?
Is the ignition wiring straight? swapping coil connectors or wires can lead to similar problems.

What did you use to rebuild the engine? There's a huge chance that it is just a botched rebuild.

We have n tester that show compression with needle, none of those testers with the nice graphs, but I'm busy trying to get in contact with local workshop to hear if they got one, the closes testers that i know of is 900km away :scared: yes we are in the middle of no ware, but will get you those numbers!

When you speak about the ignition wiring, do you mean the wires from the coil to the spark plugs? if so yes they are straight and they are connect as follow:
http://s7.postimage.org/4jkxc652j/Coil_Connect.jpg

What I used to rebuild the engine, i guess you mean the parts, the are all original Mazda parts ordered according to my vin number.

Yes but what parts did you replace?
I would double check all the vacuum hoses, solenoids, wiring etc and then do a compression test with a real rotary compression tester. Needle ones don't work :)

Just an extra detail i want to add, I did run the car's fuel tank dry ones and after that my problems began, i do have a brand new fuel pump, I'll build it in after work today and see if there is any differents

These are the parts I replaced and a new pilot bearing and Clutch disk
http://i.ebayimg.com/t/Master-Rebuil...6tw+w~~_12.JPG

Are you using an OEM O2 sensor?...the front sensor is a wideband sensor and not a normal one at that, so a normal autoparts one won't work

Yes they are OEM, i just use OEM parts ;)

Check the fuel injector wiring, it is possible to misconnect the injectors.

Just some feedback, we pulled out the engine again to open her up and see what we did wrong. We build it 100% correct, but what we did notice is that the back rotor didn't have any carbon on it, it was completely clean :uhh: so no firing/explosion was happening on the rear rotor. The front rotor had carbon on it, so firing/explosion was happing on it, so the engine only ran on one rotor. Anyone can tel me where to look for the problem?

Please note that all spark plugs and coils are firing, can it be that the rear rotor isn't getting any fuel?

Thank everyone that has helped.

Sounds likely..your options are no spark..or no fuel :)


Did you check the P injector wiring on that rotor?...it runs on the P injectors at idle and low loads...so that would result in no fuel for starting and idle for sure just from one connection

My car is running again!!! :D:

The problem was cabling of the fuel injectors, plugged them in at the wrong places :anger: She starts and purrs like a kitten now ;)

Here are the diagrams for anyone who may have the this problem.

Diagram:

https://s9.postimage.org/louweihsr/injectors.jpg

Colour Code:

https://www.rx8club.com/attachments/...ng-2005-fi-gif

Thank you everyone that help. :D:

Wiring problems...
Noob! :)

congrats on your rebuild

you have a cool dad to help with all of this and now yall know this car pretty good.
congrats and enjoy.

Hey, quick question. Would you and your father be interested in rebuilding my 13b? Weird question, hah. Let me know.

low compression after rebuild
 

Hi, Before I re build the engine the compression 4 bar's. After rebuilding the engine it was again 4 bar's. The problem is that when the engine is cold the car starts, when the it's hot it doesn't. I'm wondering if after rebuilding the engine that the engine must be working for some hour to make more compression. Because I just started it for 20 minutes and I didn't move or drive it yet. I Need some help, if any one knows what should I do to solve my problem. Please message me or leave a text bellow that would help me so much.

Very common for a rebuilt engine to have low compression until the seals bed in . You need to put a couple of hundred miles minimum on it . If it still has low compression after that ...you have a problem.

Thanks for replying I appreciate it. I just wanted to ask that the car doesn't starts when it's hot and I'm wondering why.. does compression makes this problem? or is it something else..

If anyone can help please reply. Thanks

Yes that's a common symptom of low compression. You should notice this getting better as you out miles on it.