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Bjm.Rx7 05-25-14 03:17 PM

help me please!
 
my 1989 RX7 don't have any crank angle sensor fire! i can try starting my car over and over and over again but there is no juice coming out of my angle sensor wire! can the magnet inside be gone or can a bad timing stop my sensor of having power?

misterstyx69 05-25-14 07:30 PM

you will have to give more info as to how you came up with the fact that the CAS has no Voltage and what the car is doing to believe that it is the CAS is the problem.

Bjm.Rx7 05-26-14 10:47 AM

Well, i've spliced my crank sensor to see if my problem coulb only be the clip but theres no power at all when i try to start my motor. But today i found out that i checked the wrong one as i only check the wires attached to the sensor and never checked the other wires (the female clip) refering the crank sensor clip as the male one. So i'll have to wait for my gf to come back home with the van to boost it and verify if i do have contact from my ecu to the female parts.

satch 05-26-14 11:11 AM

There is a test in the FSM which requires taking an ohm reading to test the CAS. Testing for voltage is not of much help as the system doesn't really work that way. The CAS allows for the injectors and spark plugs to fire which can both be tested individually or together.

Bjm.Rx7 05-26-14 06:15 PM

i don't know, i just noticed that when my crank sensor is unplug, the female part have 2 wires with ground (i pluged a test light on positiv post and tuch the wire) so yeah, 2 wires went on and as soon as i pluged the sensor together well all wires come on, i don't know if that can help you helping me but if all wires came on without cranking the motor, can that mean i don't have any resistance at all in that white plug?

satch 05-26-14 07:19 PM

All the wires related to the CAS should have less than 1 volt w/key to on. The test as specified in the FSM will tell you if the unit is good. W/the ECU plug unplugged (and no key!) pin 3G (White wire) and 3H (Red) should ohm out to 110-210 ohms. Same thing goes for 3E (Blue) and 3H (Red).

Bjm.Rx7 05-26-14 08:48 PM

Ok i'll check the ohms tomorrow since its late now. Can that malfunction block my spark plus wire power? Like theres no power at all coming from my coil but both of theme have power on the side wiring. So yeah my question is that can the reason why i dont have any spark in the spark plug wire come from the fact that my senso doesn't work properly?

satch 05-26-14 09:28 PM

Your Vref reading needs to about 5 volts w/key to on and if it is quite low then that could prevent the ECU from working properly. Also, there is a Green/Yellow wire at the lead coil which is the trigger wire. W/key to on and the engine turned over by 'hand' it should read 0 volts and then quickly turn to 5 volts before returning to 0 volts. You can turn the engine by hand by rotating the alternator pulley. Plug wires and or plugs could also prevent spark.

Bjm.Rx7 05-27-14 03:15 PM

ok well done! sensor resistance should be around 110 to 220... i do have 165. coil resistance should be below 1... the one near my bumper is at 1.4, the 2 one near my windshield 1 at 1.3 to 2.4 the other went up to 28... i do have power in my wire on the side but no power is coming ou my spark plus wire even if i remove those wire and put my tip right in the hole, theres no fire... is it possible that only my coil are gone?

satch 05-27-14 04:29 PM


Originally Posted by Bjm.Rx7 (Post 11743449)
ok well done! sensor resistance should be around 110 to 220... i do have 165. coil resistance should be below 1... the one near my bumper is at 1.4, the 2 one near my windshield 1 at 1.3 to 2.4 the other went up to 28... i do have power in my wire on the side but no power is coming ou my spark plus wire even if i remove those wire and put my tip right in the hole, theres no fire... is it possible that only my coil are gone?

Not sure what this means. Did you check the things in post #8. And just focus on the lead coil for now as the car can start and run fine via this coil alone.

satch 05-27-14 05:51 PM

And the Vref wire is Brown/White and can be found at pin 2I. It also can be found at the engine sensors such as the Boost Sensor.

Bjm.Rx7 05-27-14 06:35 PM

ok for my coil resistance i forgot to unplug my neg post so i did it and have 1.2 resistance in all of theme! i checked for voltage in all of theme with my key at on! have 31 in all wires! and i assume that the green and yellow wire is the one going to the coil near the bumber since its the only one i saw only have 0.2 with key on

satch 05-27-14 07:02 PM


Originally Posted by Bjm.Rx7 (Post 11743530)
ok for my coil resistance i forgot to unplug my neg post so i did it and have 1.2 resistance in all of theme! i checked for voltage in all of theme with my key at on! have 31 in all wires! and i assume that the green and yellow wire is the one going to the coil near the bumber since its the only one i saw only have 0.2 with key on


Again, not sure what you're trying to say here. Did you do the test for the G/Y wire at the lead coil as it pertains to turning the engine over by hand. And what about the Br/W Vref wire?

Bjm.Rx7 05-27-14 07:32 PM

well on each coil theres 2 wires connected in the front (both of theme have 31 v. with key on, the yellow and green wire on the coil near my bumper (its the only yellow and green wire i saw) it have a 0.2 v reading (i didn't try to turn the motor by hands since its suppose to have 5v in that wire and only have 0.2. i didn't chek the bw wire cause i didn't know if its needed to have the same v than the g/y.

satch 05-27-14 07:48 PM

There are two wires which are plugged to the lead coil. One is Black/Yellow (should have 12 volts w/key to on) while the other is Green/Yellow. As typed previously, the G/Y has 0 volts w/key to on and when you turn the engine over by hand it changes to 5 volts briefly. The Br/W wire, which is the Vref wire, has 5 volts w/key to on as previously stated.

Bjm.Rx7 05-27-14 08:17 PM


Originally Posted by satch (Post 11743565)
There are two wires which are plugged to the lead coil. One is Black/Yellow (should have 12 volts w/key to on) while the other is Green/Yellow. As typed previously, the G/Y has 0 volts w/key to on and when you turn the engine over by hand it changes to 5 volts briefly. The Br/W wire, which is the Vref wire, has 5 volts w/key to on as previously stated.

can i know where is the Br/W wire? i've been looking for it and i don't find it, maybe my wire is too dirty.

satch 05-27-14 08:40 PM

It runs to the Boost Sensor (has a total of 3 wires). Also, it is found at the TPS and AFM.

Bjm.Rx7 05-28-14 12:27 PM

ok i checked the br/w wire from the boost sensor, have 6.2 volt with key on. the yellow and green wire from the lead coil have 00.2v in it and the black and yeallow from the same harness has 15.0v in it with key on. i didn't check if the y/g goes up to 5 since i don't have time for that right now (i have my 2 kids at home and trying to work on my car when they're sleeping ahah

satch 05-28-14 04:00 PM


Originally Posted by Bjm.Rx7 (Post 11743921)
ok i checked the br/w wire from the boost sensor, have 6.2 volt with key on. the yellow and green wire from the lead coil have 00.2v in it and the black and yeallow from the same harness has 15.0v in it with key on. i didn't check if the y/g goes up to 5 since i don't have time for that right now (i have my 2 kids at home and trying to work on my car when they're sleeping ahah


Are you sure about the 15 volts? The battery itself should max out at about 12.5 volts so how you are getting 15 volts is a head scratcher. And the Br/W wire should fall withing a 4.5 to 5.5 volt range.

Bjm.Rx7 05-28-14 04:17 PM

yeah i'm sure about my reading, i used 2 different tester cause i was scratching my head to about the 15v that i don't even know how its possible to have that much v without the car running but i took my neighbor's pick up battery. so, i can't find whats my problem here unless my coil are dead since i do have power in all wires but no power coming out my coils

satch 05-28-14 05:25 PM

The G/Y is the "trigger signal" for the coil. All you have to do is measure the wire as previously described and you'll be able to narrow down your problem. You should also take a voltage reading of your battery and see what's up there.

Bjm.Rx7 05-28-14 05:46 PM

Well my batery reading is good and my trigger wire went from 0.2 to 5.3 but not all the time i don't know if i was not spinning the motor enought for my reading it only went up to 5.3 once or twice by hand

satch 05-28-14 06:09 PM

You have to spin the main pulley a fair amount for the voltage to change so you shouldn't be too alarmed. So, since you get the change then your CAS looks to be working as it should. W/that said, how about doing a simple check for spark. At the lead coil remove the spark plug wires from the coil bore and place the boots right near the bore leaving a fraction of a space between the wires and the bore. Then w/key to start observe for any flashing. If you get flashing then the coil should be good.

Bjm.Rx7 05-28-14 06:24 PM

No i already did that test even with the tool you put in the wire and theres a screw so you can see spark but none. Even my test light didn't lights up and no reading on my voltmeter.

satch 05-28-14 11:11 PM

The coil needs to be grounded to the fender to receive a ground. You might want to clean up the contact site.


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