Strange starting problem. Need help please :)
 

Ok so I more or less recently installed a new moter into my R2 and it ran great for a while but started to have starting issues.

It apeared to be flooding its self and after a few checks I found two broken air silenoids and one over active fuel injector. All were replaced and the car ran great after but after a few weeks it slowly started taking two tries to start it and had to turn it over for a few sec, when befor it would start right up. I dont drive it often but maby once or twice a month so the next time I went to strat it up it wouldnt. It smelled rich and sounded like it wanted to start but was just short of actualy turning over.

While trouble shooting we could not find anything wrong. We tried to start it a few more times when one of my friends decided to place his size 15 shoe over the end of my exhaust and it started right up. We had to move it to my new garage so we drove it down the road to test it out.

We got to my new garage and turned it off and started it again. and it wouldnt start. So i told him to cover my exhaust again and it started. We tested the therory a few times and it seams my RX will only start when the exhaust is closed off. Im going to assume it needs the back pressure, but why when the car started for years with the same exhaust?

So my question is what or why would my car need the back pressure to start? Or what other problem could cause my RX to need the extra back presure?


mods:
custom made intakes for the twins (pretty basic nothing fancy)
custom made piping and Vmount IC (larger modifided version of the Gready)
Corksport cat back exhaust.

other than suspension and wheels all else is stock.

have you checked the compression? i realize its a new engine, but this should still be done to check it off the list. Your starting problem is likely not due to having too little back pressure, covering the exhaust is just a band aid for whatever the real problem is.