Coil Resistance Question

**Bmeiers** · 06-02-2011, 02:52 PM

My 1990 rb20 has been missfiring, starting bad the odd time, and bogging out (powering down, jerking).. I just checked the resistance of my coils and it went something like this:

Cylinder 1: .9 ohms
Cylinder 2: .9 ohms
Cylinder 3: .9 ohms
Cylinder 4: .9 ohms
*Cylinder 5: .3 ohms* (really low)
Cylinder 6: .9 ohms

Arnt they supposed to be in between 1.0-2.0 ohms? Could this be my problem?

**beacher1B0** · 06-02-2011, 08:46 PM

Nissan R32 Engine Repair Manual states 0.6 - 0.9 Ohms.
As a quick maybe fix would be to re-insulate the Coils Metal wafers that are coated from the factory. The factory coating chips away easily, so mayb try some electrical tape to get u out of a bind.
If the tape or whatever temporary coating u put on the coil actually works, your in luck. Clean em up, tape em off and respray the wafers with electrical motor winding insulating enamel.
I have never tried it, but i have read several posts that it works.

**Bmeiers** · 06-02-2011, 09:34 PM

Originally Posted by beacher1B0

Nissan R32 Engine Repair Manual states 0.6 - 0.9 Ohms.
As a quick maybe fix would be to re-insulate the Coils Metal wafers that are coated from the factory. The factory coating chips away easily, so mayb try some electrical tape to get u out of a bind.
If the tape or whatever temporary coating u put on the coil actually works, your in luck. Clean em up, tape em off and respray the wafers with electrical motor winding insulating enamel.
I have never tried it, but i have read several posts that it works.

ok thanks.. so do you think that a coil with .3 ohms could cause this?

**beacher1B0** · 06-02-2011, 10:58 PM

I would say so.
Try and do the quick fix on the 0.3 ohm coil and re-meter. See what happens.
I believe the R32 Engine Manual has a diagnostic procedure for miss fires.

**Bmeiers** · 06-02-2011, 11:13 PM

ok thanks well i just read my ecu and the following codes came back.. 54-Auto signal to the ecu
12-Mass airflow sensor circut

Can somebody explain what then mean and how to fix them

**beacher1B0** · 06-03-2011, 11:45 PM

Was your car an Auto at some point?
R32 Engine Service Manual will have a diagnostic procedure to determine if your MAF is bad or wiring. My bet is yours needs to be resoldered or just needs a cleaning, also MAF harness plug tend to break the locking tabs easily, causing the harness plug to slip off the MAF.
There are posts/DIYs on resoldering the MAF, to clean just remove MAF from car and spray inside with Sensor Cleaner Spray, the wire inside is what needs the cleaning but spray the entire inside of MAF anyways aswell.

**Bmeiers** · 06-04-2011, 02:12 AM

yes i believe it must of been a auto at some point..
resouldered it yesterday and cleaned it and it didnt do much.. the circut board and solders even looked bran new
also looked in the manual and it didnt say anything..
damnit! haha

**amnash** · 06-04-2011, 02:33 AM

i was measuring mine when they were completeley removed and i was reading 0 resistance on all of them. i think seemed to be working fine before, i was just checking for peace of mind.. still havnt figured out why that happend.

now that i think of it, maybe you have to have a spark plug installed while your checking??

**beacher1B0** · 06-04-2011, 11:30 AM

Bmeiers - Look on EN 364

Mr Nash - In case you metered your coil wrong. Looking at the Coil plug head on with locking tabs up, check for resistance between the left and center terminals. 0.6 - 0.9 OHMs for both RB20 and RB26 coils.