Need Help With Coilpack Prob On Rb30 Build

[TRB-001]

hey guys, as topic suggests i have done a rb30 build into a r32, rb25det head, stock rb25det injectors, z32 afm, r32 stock ecu with r32 sensors etc.

first off i have a nistune to install and will get the ecu tuned asap however i read somewhere in the rb30det write ups that it is ok to use the stock ecu for run in period.

anyway so my problem is.... engine is in car, all hooked up, first turn of the key it starts, ran beautiful..... i wanted to run it to get oil and cool levels right, so it was only sitting there, idling with a few small lifts of the throttle. after about 10 minutes of running its started to miss.

i diagnosed it as number 6 not running, i swapped coilpacks with number 1, still missing on 6, i swapped sparkplugs with number 1 and still misses on 6. i ran it for a few minutes more while doing a upper cylinder head clean just incase something go stuck under a valve.....

anyway after doing all this i fulled the number 6 coilpack out and noticed it was red hot (burnt my finger), plastic spilling out the sides as if the coil had overheaded or shorted or whatever. so what i want to know is what can cause this, if it is only a failed coilpack then im prepared to buy a new set, but i dont want to buy a new set and have the same thing happen to them.

the coilpacks had no visible cracks when put in, they were runnning in the rb20 fine, so all in all i just want to know what could cause this problem

and is there anything i may have overlooked when doing the conversion.

any suggestions would be good.

sorry if i havnt explained myself properly.

[rob82]

hey guys, as topic suggests i have done a rb30 build into a r32, rb25det head, stock rb25det injectors, z32 afm, r32 stock ecu with r32 sensors etc.

first off i have a nistune to install and will get the ecu tuned asap however i read somewhere in the rb30det write ups that it is ok to use the stock ecu for run in period.

anyway so my problem is.... engine is in car, all hooked up, first turn of the key it starts, ran beautiful..... i wanted to run it to get oil and cool levels right, so it was only sitting there, idling with a few small lifts of the throttle. after about 10 minutes of running its started to miss.

i diagnosed it as number 6 not running, i swapped coilpacks with number 1, still missing on 6, i swapped sparkplugs with number 1 and still misses on 6. i ran it for a few minutes more while doing a upper cylinder head clean just incase something go stuck under a valve.....

anyway after doing all this i fulled the number 6 coilpack out and noticed it was red hot (burnt my finger), plastic spilling out the sides as if the coil had overheaded or shorted or whatever. so what i want to know is what can cause this, if it is only a failed coilpack then im prepared to buy a new set, but i dont want to buy a new set and have the same thing happen to them.

the coilpacks had no visible cracks when put in, they were runnning in the rb20 fine, so all in all i just want to know what could cause this problem

and is there anything i may have overlooked when doing the conversion.

any suggestions would be good.

sorry if i havnt explained myself properly.

Either bad ignitior or ecu or the signal wire for cyl6 in between the igntior and ecu is grounded.

[TRB-001]

so the coil would be permanently energized?

[rob82]

so the coil would be permanently energized?

You got it. If the cyl was on and off I would say maybe a bad transistor within the ECU or igntior but if the coil is melting and not firing at all on that cylinder than I would be looking at a permanant power supply such as a short.

[Swiper the Fox]

You got it. If the cyl was on and off I would say maybe a bad transistor within the ECU or igntior but if the coil is melting and not firing at all on that cylinder than I would be looking at a permanant power supply such as a short.

a short between the collector and emitter of the transistor will do the same (transistor cannot be switched off). Id be checking the circuit for the ground side of the primary winding from the coil pack through the no.6 transistor. A constant trigger signal off no.6 ignition driver out of the ecu will do the same (transistor always on)

Edited October 31, 2009 by DiRTgarage

[TRB-001]

ok so does the ecu act as an earth or a positive signal?

and apart from checking for a short between the ignitor and the ecu (grounding the circuit) where else should i be checking and for what?

i really appreciate your help, thanks!!!

[rob82]

ok so does the ecu act as an earth or a positive signal?

and apart from checking for a short between the ignitor and the ecu (grounding the circuit) where else should i be checking and for what?

i really appreciate your help, thanks!!!

The ecu drives to ground when it wants to energise the coil. The signal then goes to the igntior (darlington transistor) where it is beefed up. If the wire between the ecu and ignitor is constantly ground (check with igntion on) then theres your problem. If the sig wire to the coil out of the ignitior for cyl6 is gnd at igntion on then its either a wire shorting to gnd or the ignitor is stuff.

[TRB-001]

ill check that our tomorrow. thanks alot for your help guys, please keep any other tips coming.

[TRB-001]

ok update is....

going off the r32 wiring diagram, with ign on, the wire that goes from 'ecu' pin 11 to 'powertransistor' pin 6 is reading 1.2v @ where the other 5 pins from the ecu are reading 0v

pins 1 to 5 on the ecu side of the 'power transistor' have roughly 230ohms resistance to earth, and pin 6 is open circuit

pin 1 to 6 on the coilpack side of the 'power transistor' are all getting 12v

none of the wires mentioned above seem to be grounded (no continuity to earth)

and i did notice that there is 40ohms resistance between my battery neg terminal and the block so ill have to fix that earth wire.

any ideas from here? maybe rooted ecu??

[rob82]

ok update is....

going off the r32 wiring diagram, with ign on, the wire that goes from 'ecu' pin 11 to 'powertransistor' pin 6 is reading 1.2v @ where the other 5 pins from the ecu are reading 0v

pins 1 to 5 on the ecu side of the 'power transistor' have roughly 230ohms resistance to earth, and pin 6 is open circuit

pin 1 to 6 on the coilpack side of the 'power transistor' are all getting 12v

none of the wires mentioned above seem to be grounded (no continuity to earth)

and i did notice that there is 40ohms resistance between my battery neg terminal and the block so ill have to fix that earth wire.

any ideas from here? maybe rooted ecu??

The pins 1-6 on the ignitor, ECU side will be open circuit when measure to gnd with ign on so they will read 0V. Did you disconnect the Ignitor when doing this check - if so the number 6 coil driver within the ecu is stuffed.

[TRB-001]

yeah the ignitor was disconnected and it still measured 1.2v while the others were 0 volts

the power transistor also has a a short between ground (E) and number 6 collector/output so it looks like thats stuffed.

so it seems ecu and transistor are rooted, coilpacks (both involved in diag process) could all be rooted however im not sure which was the root cause of the problems.

i forgot to mention, when doing the conversion i used the rb25det power transistor (pluged into the r32 wiring and ecu), when i went to start it first, it cranked but did not fire, i realised straight away and swapped it with the stock rb20 r32 item and it fired straight away, ran for ten minutes then started to play up.