fcrotory

iTrader: (20)

I did a s4/s5 long block swap. All s5 parts on s4 block. Now car won't start. Not using emissions rack or 5/6 ports actuators. Any ideas???

RotaryEvolution

iTrader: (30)

try sticking to one thread and be patient for help...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-4-a-937221/

start with the basics:

check for spark
compression test the engine
check fuel pressure and for injector firing

if the car is starting for a second or 2 you can pretty much rule out an ignition issue, compression still may be iffy. check fuel by testing fuel pressure before, during cranking and with the engine running to see if it is dropping off causing it to stall out, you can also test it by spraying carb cleaner into the throttle body and reinstall the intake duct/AFM and try to start the car. be sure the AFM is plugged in and double check your vacuum lines to make sure there is no leaks in the system, it only takes a few small vacuum leaks to bypass the AFM and cut off the fuel pump switch causing the engine to only run for a few seconds at a time. you can test that last theory by jumpering the fuel pump test connector at the RF strut tower(yellow 2 pin connector, run a wire from one pin to the other and try to start the car).

additionally, if the engine you installed hasn't been run in a long time it may need some additional lubrication to help build compression to keep it from flooding out. get a few ounces of MMO/2stroke oil into each spark plug leading hole and retry to start the engine.

fcrotory

iTrader: (20)

It has 100 lbs in both rotor housing. It's got a fresh rebuild on block. And we plugged off alot of vacuum. Maybe too much?? And the primary wires could be backwards. Timing could be off too. I had to swap front covers.? How do I set timing??

RotaryEvolution

iTrader: (30)

steps for setting timing are in the FSM and some how to's on the forum easily found with a search.

but your issue sounds fuel related.

fcrotory

iTrader: (20)

Ya, I read the fsm under the engine chapter. Car only started once. Can't even get it to run now. It's seem like if I mess with timing it tries more and more. Could backwards injector plugs do that?

RotaryEvolution

iTrader: (30)

yes, injector plugs in the incorrect location will cause it to be difficult to start, but with an n/a that is nearly impossible unless you are trying. it sounds flooded at this point, re-stab the CAS correctly and add oil to the rotors or do the deflooding procedure by removing the EGI fuse, crank then reinstall the fuse.

fcrotory

iTrader: (20)

What about vacuum? Is there certain places where vacuum shouldn't be plugged? I've been doing none stop research and this is the only info I got. I appreciate the help.

RotaryEvolution

iTrader: (30)

you can cap off any of the vacuum ports and it shouldn't affect how the car idles much or cause a no start condition, unless some of them were left uncapped. any leaks in the intake tract bypass the airflow meter causing it close back up after starting which turns the fuel pump back off, shutting the engine down.

fcrotory

iTrader: (20)

Ok that's good to know. I'm gonna mess with it some more. Check vacuum and stuff. Thanks again for help.

RotaryEvolution

iTrader: (30)

np

fcrotory

iTrader: (20)

Update:
Cars start up fine now but won't rev fast. Can rev high if I slowly open Tb. But if I try to slap it open it Jus cuts and backfires. Starts fine though.