NoPistons -Mazda Rx7 & Rx8 Rotary Forum

NoPistons -Mazda Rx7 & Rx8 Rotary Forum (https://www.nopistons.com/)
-   Rotary Engine Building, Porting & Swaps (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/)
-   -   New Rebuild Starting Issues (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/new-rebuild-starting-issues-25255/)

ryosuke_fc 09-24-2003 09:11 PM

Well, we tried pull starting it today. It coughed a lot of smoke, but that was about it. Still never fired up. We had the intercooler off because we put some starting fluid in the throttle body before that, which is probably a no-no. I donno if that would have anything to do with it. I'm quickly running out of ideas though. :(

BigTurbo74 09-25-2003 01:30 AM

did you have it soaking in oil? when i pushed started mine i had to do it many many times but every push it became easier to start. keep trying!

75 Repu 09-25-2003 01:53 AM

This may sound stupid.. but are you sure the wires on the plugs are hooked up right.. the vert I bought would not start because of this.. once I fixed that it never gave me a problem again..

ryosuke_fc 09-26-2003 12:30 AM

What do you mean, did I have it soaking in oil? We oiled the engine per the Haynes manual when we put it back together. The engine is getting oil pressure when try to start her up.



Maybe I should doouble check all the wiring. Is there a good wiring harness diagram somewhere online? The Haynes manual didn't really have crap, so we pretty much has to guess by the memory of the wires and the connectors. All I really need is something that shows the wiring harness and the connectors in order from one end to the other and says what they all go to.

BigTurbo74 09-26-2003 01:03 AM

this wiring is probably your problem. check fc3s.org for the factory service manual, good way to double check everything else to troubleshoot too.

mperformance 09-26-2003 02:03 AM


Originally Posted by ryosuke_fc' date='Sep 22 2003, 06:24 PM
We did run a compression test and were seeing about 75 in the rear rotor, but only like 40 in the front. :( I'm not sure if this is cause for concern on a new rebuild, but it seems to me like it should be. :( This is a full rebuild with all new hard parts, gaskets, and bearings.

Sorry but 40psi is way to low if using all new parts.



I just finished rebuilding a 12a with all used parts except for new apex seals and soft parts, all of the reused parts were checked properly specially side seals and corner seals.



I have been testing compression everyday this week and it started up pull started with a compression of 80 and 75 psi cold (no oil added), now after 4 hours of idling is up too 83 psi and 80psi when hot. It's still difficult to start but it starts up with a few drops of oil since it floods easily due to having a weber carb and no fuel cut off for it since the carb holds gas in the bowl.



Your engine should start pull started even at 65 psi but 40psi is too low and might be a bit difficult but it's doable, you should check internal specs again if everything else fails.



sorry for the bad news.

BigTurbo74 09-26-2003 11:45 AM

how where u measuring compression?

ryosuke_fc 09-26-2003 04:49 PM

Using a compression tester in the spark plug hole, while cranking the engine.

ryosuke_fc 09-26-2003 11:46 PM

Well we got her running finally. https://www.nopistons.com/forums/pub...#>/biggrin.png We pull started it in reverse of all gears. We noticed it seemed to like reverse when we pushed it down the driveway to start off with so that's what we used. The idle was real rough to begin with but it seems to have smoothed out, though it still bounces a little bit. At first it wasn't wanting to idle at all. Then it would idle at like 500rpm, but we noticed that we forgot to hook the BAC back up so after that it's up to about 750rpm, and it will hold the idle better. We drove it around the neighborhood for about an hour, and it seems alright. There's a pretty big jump in power around 1500rpm though, which I'm not sure is normal. Below that it doesn't really feel like it wants to go, but above that it accelerates a lot quicker. Now our problem is getting it to start on it's own. It will push start relatively easily, but it won't start by itself. Any ideas as to why? I killed it at a stop sign a couple times(my first manual car), and we had to roll it back to get it to fire up again. If we just drive it more will it start on it's own, or is there something else we need to check?



Thanks for all your help thus far, by the way. I really appreciate it.

BigTurbo74 09-27-2003 03:08 AM

try to get it to idle as well as possible, then get out and spray starting fluid on all of the parts that connect to each other,(injectors, manifolds, ect.) see if the idle revs up,


All times are GMT -5. The time now is 08:37 PM.


© 2024 MH Sub I, LLC dba Internet Brands