RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   need help i have no spark (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-help-i-have-no-spark-708861/)

madazfiend/1 11-29-07 03:45 PM

need help i have no spark
 
did t2 swap on my n/a now i have no spark. let me know some pointers.thanks

NoDOHC 11-29-07 08:09 PM

Is everything properly connected (CAS, computer, coils?)

Do your injectors click if you spin the CAS (Crank Angle Sensor)?

Check and double check connections is about the best advise I can give.

RotaryX 11-29-07 08:12 PM

Need some more info. Stock ecu?

HAILERS 11-30-07 08:41 AM

Engine fuse blown or EGI fuse.

EGI fuse supplys the 12 to the Main Relay.

Engine fuse supplys 12vdc to pull in the Main Relay.

Then coils get 12vdc from the Main relay on a black/yellow wire. So check for 12v on that wire, especially at the Lead coil assy.

IF your fuel pump runs when the fuel check connector is jumpered, then the Engine fuse and main relay are pulling in and have power. If that's so, then what I wrote above is mute.....almost. I'd still check for 12v at the black/yellow wire and batt voltage at the ECU plug at each injector wire. Series four would be at the small plug, green/white, light green. light green/black, light green/red. PUll the plug off and check those wires at the plug.

IF you've a spare cas, then attach it to the harness like the man above said, and key ON, spin the bottom gear of that cas and you should hear spark and fuel injectors clicking. If not, then you've no voltage at the coils.

It's ASSUMED you have the plug on the cas and all the plugs are on the ECU and all the plugs on the EM harness are connected up, especially those two orange ones above and to the right of the passengers feet that mate with the Front harness.

drift monster 11-30-07 10:53 AM

my car just started this.


it sparks when u first crank it and spark when u stop cranking, it seems like the starter is taking all the voltage and not giving any to the coils

madazfiend/1 11-30-07 03:00 PM

dose the right side harness connect with the left side harness some were.all i did was use the right side harness that came with the motor and the ecu that came also and installed everything the same way it was pulled

madazfiend/1 11-30-07 03:03 PM


Originally Posted by NoDOHC (Post 7567474)
Is everything properly connected (CAS, computer, coils?)

Do your injectors click if you spin the CAS (Crank Angle Sensor)?

Check and double check connections is about the best advise I can give.

i hope everthing is installed right.lol.do i keep the cas connect to the harness when i do this

HAILERS 11-30-07 03:20 PM


Originally Posted by madazfiend/1 (Post 7570295)
dose the right side harness connect with the left side harness some were.all i did was use the right side harness that came with the motor and the ecu that came also and installed everything the same way it was pulled

The EM harness on the engine mates also with the FRONT harness, using two ORANGE plugs above the passengers feet and off to the right. The FRONT harness does only minor functions. Like supply the ECU and injectors with batt voltage.

You don't state what EM harness you used. USA Turbo? JDM turbo? Non turbo (best choice of all).

madazfiend/1 11-30-07 06:33 PM


Originally Posted by HAILERS (Post 7570360)
The EM harness on the engine mates also with the FRONT harness, using two ORANGE plugs above the passengers feet and off to the right. The FRONT harness does only minor functions. Like supply the ECU and injectors with batt voltage.

You don't state what EM harness you used. USA Turbo? JDM turbo? Non turbo (best choice of all).


I used usa turbo em, i hope .the guy i bout it from told me it was an 88 t2 but for some reason it came with s5 turbo but who knows. just got back in side and took the intake off to make sure every thing was hooked up right.

HAILERS 11-30-07 06:56 PM

1 Attachment(s)
You need to go to Rotary Rescurrections site and modify your turbo EM harness to fit a non turbo Front harness.

Bottom line is a Turbo EM harness is really not compatible with a non turbo Front harness. Just a couple of wires need changing.

It's not possible to help any further without going out and use a meter on the plugs etc.

Actually there's only two wires in the turbo harness mating with the non turbo front harness that will cause heartburn.

I'd bet the engine fuse is blown.

FYI....The stock non turbo EM harness is virtually plug and play if you forget about the twin scroll solenoid and knock sensor. Neither of which is required to run and drive the car.

EDIT: There should be a jpg attached. It's of one of the plugs on the EM harness that mates with the Front harness. See the letters with the ( )around them? They are Peculiar to TURBO EM harness. Those ( ) wires are not compatible with non turbo Front harness wires without the ( ) around them.

The only one that can blow a ENGINE fuse would be the one with (BrR) around it. It's a Brown/Red wire going to the boost sensor and also to the ECU pin 2B. Not good.

I'd also say your water temp does not work either. YW wire. Nor the alternator.

The ENGINE fuse is shown in the FAQ thread at the beginning of this site. It''s on the third row from the bottom, second one over from the left.

HAILERS 11-30-07 07:21 PM

I see you have a series five turbo. No twin scroll needed. The stock na harness would have been plug and play....virtually. Sorta.


All times are GMT -5. The time now is 06:56 PM.


© 2024 MH Sub I, LLC dba Internet Brands