A little background - Bought an 87 RX7 N/A that had been sitting in a garage for 6 years and surprise, surprise... no compression. Need the car running ASAP, and the only N/A engine I could find was from an S5 vert. Followed RotaryRessurection's guide for the swap, removed most of the emmissions (kept BAC, cold start valve and the vacuum actuator, thermowax, dashpot, double throttle butterfly plates, and cold idle cam and spring; starting to think this may be part of the problem) installed aftermarket air filter and custom exhaust. Finally got the engine in the car and it won't start. It turns over, and I can hear it wanting to start, but it never does. I thought it might be flooded, so I tried the EGI fuse trick, no dice. I read on another forum about disconnecting the solenoid resistor, so I tried that. With the resistor unplugged, the car would start, rev up to about 2 grand, and then die. After plugging the resistor back in, the car would act the same as before. I've checked the fuel system, the solenoid resistor, the ignition coils, the spark plugs are brand new, the wires are good... I'm stumped. I've gotten much help reading threads on this forum, so I know someone out there can help. I greatly appreciate any advice.

 

Did you just swap the S5 block into the car? Or the entire S5 engine with injectors?

S5 injectors are high impedance, so you don't need the solenoid resistor. Jumper it.

You will need to have used the S4 AFM, so it sounds as though it may be bad.

 

my s5 has the solenoid resistor at the front right of the car behind the headlight. my car is doing the same thing...........how do you jumper it to bypass it?

 

You shouldn't be jumpering the solenoid resistor unless you are in a situation like the OP. Also, your S5 will have high impedance injectors and thus no solenoid resistor.

 

Just the block, I'm using the S4 injectors.

I thought my incomplete emissions removal might be the culprit, so I removed the rest of the stuff indicated in RotaryRessurections guide. Still didn't start. While me and my father were messing around, I had an idea. By my logic, disconnecting the resistor effectively disabled the injectors, allowing the engine to burn off any fuel that had flooded the engine, and shutting off after all of the fuel had burned off. So, I basically re-flooded the engine, unplugged the resistor, and had my father reconnect it once the engine turned over, restoring the fuel supply. It worked! Kind of. The engine ran, but it was EXTREMELY rough. The engine was shaking like crazy, and there was ALOT of popping, which I figured was afterburn. So I figured that my problem was too much fuel. Which would make sense, because everytime I try to start the car, I can feel it trying to turn over for about a second, and then nothing. I think its flooding everytime I turn the key. Any suggestions on what may be causing this overload of fuel?

 

And to Aaron, technically, engine and motor are both correct, although engine is more specific. Although the definitions are a bit ambiguous, generally speaking, an engine burns fuel, and a motor doesn't. I prefer to say engine.

 

Just bought and installed a new fuel pressure regulator, no change. Any advice?

 

FPRs almost never fail.

If the injectors have been sitting for 6 years, it is certain that at least one of them has failed. They need to be professionally cleaned and tested.

 

Injectors are new.

 

As in, brand new?

Are the ignition leads in the correct order? Perhaps leading swapped with trailing?

What is the history of the new engine? Compression tested?

 

Brand new injectors. I checked and double check the leads, and then I checked them a few more times just to be sure. I bought the engine from a guy who make a living selling FC3S parts. It came from an automatic S5 vert. The engine was still in the car when I went to look at it, and it ran just fine. The seller pulled the engine the same day. I brought it home, stripped it down to the core, and installed all of the necessary S4 parts, minus the emissions stuff.

 

Oh....Just be aware that you need to swap on the manual front counterweight from an S5 and well as an S5 flywheel to keep the engine in balance.

Is the CAS stabbed correctly? Did you by any chance swap the front pulleys from the S4 engine onto the S5 engine?

 

I bought an S5 flywheel and installed it, and I swapped the entire front cover from the S4 to the S5. I didn't mess with the CAS at all.

 

So, did you position the CAS according to the FSM/Haynes manual specs after installing the S4front cover?

And again, did you mix and match S4/S5 pulleys and hubs?

 

I used the S4 pulleys, and I'm not quite sure what you mean by hubs.