sweetchuck

Ok, I'm having a problem with my 1987 N/A RX7. It will start up and drive, but after it's warmed up and I push on the throttle, the motor cuts out. When driving the car, it's good to go around the block, but soon it starts cutting out. I've replaced the mass air sensor, fuel filter, spark plugs, plug wires, crank sensor, and I put some different coils (from a junk yard). Nothing has been able to fix this problem. Any help would be appreciated

CrypticApathy

Are you sure its getting enough gas? it maybe able to handle the amount of gas your putting in it at lower rpms but once you start to move up in rpms the fuel may not be getting to the motor and your running it dry. I didnt notice your fuel line being replaced in the stuff you mentioned so it may be cloged or broken. Also check your ports make sure all of them are working. Are you running low on gas alot quicker then normal? Also make sure your not over heating it. Do you have proper cooling? Is the motor smoking, check your radiator fluids.

Tessai

What RPM does it start doing this?

sweetchuck

I know the lines are not clogged, when we replaced the fuel filter we blew out the lines with an air hose. I believe it starts cutting out at 3500 rpm's. Yes it does smoke until it gets warm. It has never had an overheating problem.

fc3s4utnv

Make sure you clips on you secondary fuel injectors are tight, one of mine kept poping off, and it would have the same issues.

Chuck

Sounds like it might be one of a couple of things

- like was mentioned above, check that the electrical fittings on the secondaries are well connected

- the grounds from the ECU to the top of the block might be frayed, corroded or broken. check the voltage of the ECU's grounds. There are 3 or 4 of them. Ground pins are supposed to show 0.0 volts. If they show a positive voltage, splice a 10-12 guage wire to a ground point on the car's frame.

- You might also benefit from adding a ground wire from the battery negative terminal to the car's frame and a ground wire from the alternator body to the car's frame.



RX-7 grounds are notorious for wearing out over time. A lot of people with problems like the one you describe have benefitted from cleaning up the grounds.

matts86fc3s

do a volt sweep test on your throttle position sensor... make sure there are not opens or blips in the readings... at closed it should be 1ohm and at wide open throttle should be no more than about 5.5ohms... if it goes past 6ohms or the reading cuts out or goes to infinity while sweeping the throttle then it could cause that... checking out the ground would also be a good thing... mine is doing the same thing right now and ive grounded almost everything there is to ground... no help on mine...

sureshot

(Continuing from post #7)

A quick test.

Unplug the TPS & see if the problem goes away.