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RX7 STARTUP PROCEDURE FOR THOSE INSTALLING THEIR OWN ENGINES

  • Leave oil filter off during install. . Check block coolant plug for tightness. Check oil pan drain plug for tightness. Fill 5.5 quarts oil, 1 gal coolant, 1+ gal water. For engines that have had the cooling system modified/simplified, sometimes vapor lock will cause the engine to seem full of coolant when in fact it isn’t, so be sure to measure the volume you put in and don’t start it until you are sure it is full of coolant, or overheating damage can occur if started with a large air pocket and not enough coolant in the engine. I recommend 10-30 oil for startup. Connect a battery charger if necessary, for a strong battery. Do not install new spark plugs, as they will likely get fouled during startup/breakin. Use some old used plugs for this part so you don’t ruin a $40 set of new plugs.

  • IF you know FOR A FACT that the oil pressure gauge in your car functions, you may skip the below procedure for visual verification of oil pump priming and instead simply disable spark/fuel by unplugging the crank angle sensor(s) OR the ECU OR removing the EGI fuse(s). Then install the oil filter and crank the engine for 10 seconds or so and watch when the dash gauge builds oil pressure, then replace the fuses/plugs you disconnected and skip to the idle adjustment step below. IF you are unsure whether your dash gauge functions or if you do not get oil pressure indicated, I recommend visual verification of oil pump priming as below.

  • Place one or more shop towels etc. under/around the oil filter pedestal.

  • Make a remote starter control wire from about 6-8 feet of single strand wire (any gauge, 14-18 works best) and a flat female wire connector crimped on one end, half an inch of bare wire stripped on the other.

  • Reach under the car and unplug the single wire to the starter solenoid. Plug in your custom starter wire. Reach it around the outside of the car and over to the battery.

  • Ensure that the car is out of gear/neutral (manual models). DO NOT TURN ON THE KEY TO THE ACC POSITION, leave it OFF. You want the ECU to remain unpowered, so that the plugs will not spark, the fuel injectors will not spray, and the engine will not start yet. You’re only trying to physically rotate the engine internals so that the oil pump can prime.

  • Touch the bare wire end to the battery + post. The engine will rotate. Do this first for 7-8 seconds, then stop and continue in 1-2 second increments until you see oil squirt up and out of the oil filter pedestal hole. Quickly use the towels to catch any spilled oil. Install your filter and continue to crank in 2-3 intervals for 10 more seconds or so to pump oil through the rest of the system. Remove your custom wire and replace the stock wire on the starter.

  • Locate the idle coarse adjustment on your engine’s throttle body. Usually it is on top and has an 8mm lock nut surrounding an adjusting screw or set screw. Loosen the lock nut and rotate the adjusting screw 2-3 turns clockwise. This should manually raise idle to the 2-3000rpm range.

  • Bump engine over with a ½ second hit of the key to ‘start”. Wait a few seconds and repeat. This will prime and pressurize the fuel system. Get out and inspect the fuel lines and rails for any fuel leaks prior to startup.

  • Get in and start car. Be prepared to pump/hold the throttle immediately so that the engine runs in the 2500-4000rpm range. EXPECT HEAVY SMOKE and slight misfiring as assembly oil is burned off. Do not let engine bog or stall during this phase, continue to keep it running. After about 30 seconds it should clear up and run more smoothly. Continue to hold rpm in the 2500-3000rpm range for about another minute.

  • After the engine seems to be running smoothly, slowly back off the throttle and see how it behaves without your foot on the throttle, but do not let it stall. It should continue to run in the 1500-2500rpm range.

  • Now you can get out and inspect the engine for issues, leaks, noises, etc. Don’t shut it off unless there’s a very good reason to. If it is running smoothly and will stay stable, then adjust the throttle body coarse idle adjustment to 1500rpm or so.

  • Verify that the thermostat opens as the engine coolant heats up by feeling the upper radiator hose get hot, and that eventually the cooling fans kick on and operate (FD models).

  • Once you’re satisfied that everything is okay, get back in and go for a test drive around the block. Bear in mind that the engine is going to be very weak at low rpm and have poor response, so you will have to slip the clutch (manual models) and apply more throttle than usual to get going. If the engine rpm drops below 1000rpm it is likely to stall and not restart.

  • Automatic models load the engine significantly when put into gear and are more difficult to get going in than a manual, so it may not be possible to avoid stalling when you attempt to drive it after first startup since you cannot drop them into gear at rpm ranges higher than ~1000 without possibly damaging the transmission. Expect that it will stall and not restart when you pull it into gear.

  • Once you get going, stay under 4000rpm and about half throttle or less. At stops remember  to pay attention to the rpm because the car may not idle yet, and if it stalls at this point, it is probably not going to restart for at least half an hour. IF it stalls while rolling at 10mph or faster (manual models) you can quickly pop the clutch in gear to get it going again.

  • It’s not a bad idea to make a short trip then come back for a quick inspection for leaks, be sure the cooling fans engage at operating temperature (FD models), etc.. Now you can go out onto the highway if you’d like.

  • When your initial test drive is done, shut it off. Do not expect it to restart for at least half an hour to an hour. Let the engine cool somewhat then check coolant level, oil level, leaks, etc. You can try to restart it after it cools off for a while. Don’t crank excessively or you’ll flood it badly and foul your plugs, which are no fun to change. If it doesn’t start within 5 seconds, it probably isn’t going to. Let it cool off longer and try again later.

  • Be sure to re-check oil and coolant levels for the first few days after initial startup. Sometimes air bubbles will continue to make their way to the top of the system for 2-3 days so the coolant level must be topped off during this time.

  • As you perform multiple heat/cool cycles and drive the car, the engine will build starting crispness and idle smoothness, and you can experiment with bringing the idle down.