Hi everyone,

Im new to this forum and im asking for help, ive bought a shell and build the motor from scratch and finally finished building and already installed in the engine bay. gorund wires are connected and now makes crank, in the initial attempt it started for a few seconds with the help of engine starter fluid, but that was it.
it wont run, ive replaced all sensors in the engine bay, new spark plugs, new spark plug wires, trails seem to work since ive tested with the crank angle sensor, battery is new from optima. starter is working, new fuel pump from rock auto, new fuel filter, tps setting is about 1.6 which is the tightes i can get from the throttle body, car keeps flooding and ive pulled spark plugs many times to clean off fuel.

a few things im curious that might cause the issue.
1) im thinking the thermo wax sensor : not sure if it plays a factor to have it run
2) im currently using a N350 map pressure sensor but i know it should be a N326, since my ecu is a N326, not sure if its a big deal that can cause it from running.

im so eager to have it run can anyone please help me with this, i was really looking forward to drive it this year.

 

Alamost there, yet still so far away.
On a rebuilt engine, timing should be verified. Spark from both coils and fuel delivery. Next is checking vacuum leaks. Not necessarily in that order.
There was a similar thread about this and holding open the door flap at the AFM did the trick.
I am not sure about the sensors. I never had starting issues even without the tps plugged in.
Staring and immediately dying was always a massive intake leak or a vacuum leak. I could be wrong about the tps, though. Disabling the thermowax and setting the tps is probably a good idea.
Also, if you have a meter, verification of the sensors at the ECU and vice versa helps, too. The FSM has a chart on which side to test from.
Hopefully you'll get some more eyes on this, as I probably missed something pretty obvious to check.

 

Thank you I’ll look into those, especially the timing. I never thought there was something that kept it timed. and I’ll try that AFM flap trick

 

Yep, first thing to check in a rebuild, probably. And likely best to check before the engine is in the car, not sure though.
Second is a compression check. I don't know much about rebuilds but from what little I do know. The compression should increase as the engine wears in and level off, if I remembered correctly.

I think you will need to pull the CAS for the timing check.
As for the lines on the pulley, some have disappeared due to rust. Be very careful with both the CAS setting and those marks.



I believe this is correct for the marks. Someone please correct this if I did this wrong.

I painted the pin white so it was easier to see, along with the factory colors for the marks. The FSM is easier to translate into useful information that way.

 

any new engine i always give it around 1/4 throttle and hold it around 2k RPMs to keep the engine running for around 30 minutes, a rebuilt engine is very easy to flood out before allowing all the seals to seat in and build up compression on.

you may need to add some MMO to get it restarted at this point if it is a flooding issue. if you are unsure you stabbed the CAS correctly just try adjusting it around and see if it helps to get the engine running.

you can of course verify it isn't a lack of fuel/fuel pump issue by using some starting fluid in the intake and reinstalling the AFM.

drying off the plugs with starting fluid if they are soaked in fuel is a good idea, and crank the engine with the plugs out and EGI fuse removed to deflood the engine is a good thing to do.

some folks get a little too crazy with vaseline, grease, assembly lube or silicone and that fouls up the ignition on first start.

 

ok so good news and bad news, I First checked around the motor and found 2 small tubes not plugged and fixed the issue

second I deflooded the engine by exactly removing the plugs and EGI fuse by cranking 20seconds but before doing that I added a little bit of oil in the spark plug holes

third I re checked and corrected the CAS and pulley to get a good timing

fourth I just put one spray in the air intake

The car did start and I was able to rev the engine for about 5 seconds and let go of the key and maintain with the pedal revving the motor and as soon as I let go of the pedal for a second it died, and was not able to turn on again which I guess the engine flooded again. so I again deflooded the engine but not touched the timing of the CAS and pulley, the car only cranked and small pop noises but not started like the first time. I'm guessing the timing might be off again?? is that even possible? and I tested the CAS by turning the gear by hand and was able to hear small clicking noises from the trail and lead packs.

 

You have spark and fuel. Have you done a compression test?

 

I have not, I’ll try to test and let you know

 

sounds like its time for the compression test, if its down at 60 or less the engine will never want to start or idle without a lot of unnecessary prep work.

 

so far ive done the spark plug test and all have been flickering, which is good but ill try the compression test, and hoping that might be the issue, if it is the issue, what could I have missed on the rebuild? I know I placed new water jackets, new corner seals, new side seals, new apex seals and I believe I was generous with the hylomar sealant.

 

the apex seal corner pieces can easily jump out, i have had that happen a few times. or the rotor housings might just be too far gone to accept new seals.

 

So here is an update,
Ive been in school and working so havent put alot of time and love to the rx7. but now ive been fiddling with it. coolant seems to be leakin a little bit from the water pump area, easy fix. next ive checked all vaccum lines are sealed. i checked timing and the crankshft postion sensor as well. cleaned out the sparkplugs from flooded fuel. it cranks and starts very rough and reved up for 5 or 7 seconds and then it just slowly dies down. so this tells me that it wants to start but then gets flooded again. im wondering if my TPS could be the issue? or maybe the ECU? it just seams the timing is not accurate with the fuel and air, i know sparks working cause i tested the plugs, i wish i couldve done the compression test but didnt do it. im even tempted to buy the actual compression test specifically for the rotary engines. if it runs but sounds horrible, i would so happy with that, cause its only the settings for throttle and the other sensor located near the air intake.