VN S1 Ignition Coil OHM Results....

[shmickmik]

Hey everyone

I am having a problem with the car atm.. its not exactly a problem more of a nuisance really..

When taking off the car seems pretty shaky and rough, and nowhere near as smooth as it should be.. I know they are meant to be rough, but if this is how the cars were sold its a wonder ANY of them were sold!

There is also a slight hiccup in the idle when sitting at the lights, and when braking you can feel the car jolt foward as if its gaing a sudden surge of power.. its wierd.

Anyway lol

I was testing the resistance of the coils (S1 Coilpack) and i got a constant 14.9ohms i think it was.. or 14.5 .. something like that.. I checked the manual and it said it should be between 10-14ohms.

When the coils are on their way out does the resistance usually go up or down normally?? I just dont want to go and upgrade to a S2+ coil pack to find out that there is nothign wrong with mine atm :P

Oh and when doing an ecu check, i have always received a code of 13 (Oxygen Sensor).. I have swapped 3 different sensors, 2 of which were the 2 wire sensors (modded to fit the S1 loom) and the engine light still comes on when starting the car and for the first 30 seconds of driving.

Cheers all

[Cheap6]

Coils nearly always fail high or open circuit. The 14 plus from yours is probably grounds for replacement. If the rest of the ignition system - leads, 'plugs - is perfect you can get away with readings that high sometimes but it's not good. How many of the coils were over 14 Ohms?

That is for the secondary side of the coils. The primary side can also fail. With the the coil pack removed, the resistance across the pairs of wires should be low. Off the top of my head I don't know the spec. but 1-1.5 ohms would be a reasonable guess.

Code 13 is an open circuit for the O2 sensor. As you have already swapped sensors (which might not be any good either if they are used) it's possibly in the wiring on the car. I think that the earth for the O2 sensor is the one on a timing cover bolt. Otherwise it's a matter of checking the wiring back to the ECM. It's also possible the fault may be within the ECM.

The jolt forward sounds like the IAC motor bumping up the idle speed. If the engine isn't idling smoothly and consistently, the ECM won't be able to learn a IAC motor position with which to start and will always be chasing the varying idle speed, so while cleaning it and the throttle body and plate may help, and wouldn't hurt, fixing the rough idle will possibly fix that.

VN V6's are also known to burn exhaust valves or lift inlet manifold gaskets (the latter problem can lead to the former due to cylinders running leaner than the average) either of which will also give a rough idle.

[Not_An_Abba_Fan]

The code 13 would be related to a misfire, especially if the engine light stays on for around 30 seconds. The O2 sensor isn't getting hot enough soon enough. If you can get your hands on another set of coils and DFI, swap them over and try it.

[Cheap6]

If it was a 44 it might be related to a misfire; the O2 sensor picks up the uncombusted oxygen in the exhaust gas and reads it as lean, ignoring the fuel. The 13 is an open circuit somewhere, which is why it will come on when the ECM doesn't 'see' the voltage it puts out on the O2 sensor circuit.

[aussieghostrider]

I believe my cars got a coil problem as well , at lights in D I'm getting a slight vibration noise & when throw car in N it disappears and If I rev car then put in D the vibration comes back after few seconds , If I dont rev it vibrations is there as soon as car comes to a stop.

The coil pack is s1 and has never been touched since car was bought new in 1990 and the IAC has not been touched either ... so thats 18 years of use ..

Im going to have IAC cleaned and reset & the coil pack replaced with a new one , I was told it's an easy swap over.

Also it's not the CAS as the car has never stalled and I tried pouring cold water of it when hot and it did not affect the vibration.

I was told if car has a misfire that can cause the vibration im getting as well , seems to only do it when cars warmed up so coil packs getting overheated i suspect as Ive changed leads, plugs , cleaned throttle body , fuel filter & put upper engine cleaner, and even reset the computer.

[Not_An_Abba_Fan]

Open circuit on the sensor could mean that it isn't hot enough to go to closed loop though. If it remains in open loop for more than a minute I think it is, then it will throw code 13. If it isn't firing on all cylinders, unburnt fuel will keep the sensor under operating temperature. Just my theory on it.

[peter65]

i had the same problem described above caused by an open circuit spark lead... at idle it was missing but at revs it was ok as (i presume) there was enough spark to bridge the open circuit in the lead. A quick check with an ohm meter proved it. peter.

[natalie.may]

Hay there guys,

I was wondering if u guys culd help me out, ...
Recently my partner and i have bought a VN 1989 S1, when we got the car he put all new leads on.. A few days after having the car it wouldnt start, instead it was more of a burbly sort of sound, and wuld only start when fully reved, my partner seems to think that i could be the coil pack or the spark plugs, (he went through and cleaned them all) - also i am pretty sure its only running on 5 cylinders instead of 6.. When starting or shortly after being turned on the engine light will always come on and off.. when my partner leaves for work sometimes it will start fine then turn off then wont start till reved then once started sounds like its going to cut out and black smoke flies out of the exhaust... he also thought it might be something with the fuel so he has been putting this lube fuel cleaner stuff in there and aparently its working.... also this morning when he left for work my neighbour and i both said it smelt as if it is running rich of fuel.. and on the road the was a liquid but couldnt be to sure of what it was due to rain.. :S everything else with the car seems to be fine .. i dont know much about cars but i know a lil and im suck... lol
anyway help would be muchly appreciated guys, thanx ..

[Brett_jjj]

Hay there guys,

I was wondering if u guys culd help me out, ...
Recently my partner and i have bought a VN 1989 S1, when we got the car he put all new leads on.. A few days after having the car it wouldnt start, instead it was more of a burbly sort of sound, and wuld only start when fully reved, my partner seems to think that i could be the coil pack or the spark plugs, (he went through and cleaned them all) - also i am pretty sure its only running on 5 cylinders instead of 6.. When starting or shortly after being turned on the engine light will always come on and off.. when my partner leaves for work sometimes it will start fine then turn off then wont start till reved then once started sounds like its going to cut out and black smoke flies out of the exhaust... he also thought it might be something with the fuel so he has been putting this lube fuel cleaner stuff in there and aparently its working.... also this morning when he left for work my neighbour and i both said it smelt as if it is running rich of fuel.. and on the road the was a liquid but couldnt be to sure of what it was due to rain.. :S everything else with the car seems to be fine .. i dont know much about cars but i know a lil and im suck... lol
anyway help would be muchly appreciated guys, thanx ..

Id try checking the 3 ignition coils (or coil pack),once they get old,these can break down under load and cause misfiring etc.Its easiest to borrow a known working coil to try it where yours usually go, to see if it makes any difference to how it runs etc..Its also worth checking the fuel pressure regulator,when these get worn out,they can leak fuel into the inlet manifold and cause all sorts of problems including misfiring ,black smoke coming out of the exhaust etc.Mainly when its first started up though.Id also check the computer for logged error codes.This test is quick and easy to do,heres a link to a post that shows you how to do this test.If an error code has set,it can cometimes point you to the cause of the problem.
---Checking your Computer for Faults (VN - VP)---
.

[Circlotron]

I was testing the resistance of the coils (S1 Coilpack) and i got a constant 14.9ohms i think it was.. or 14.5 .. something like that.. I checked the manual and it said it should be between 10-14ohms.

When the coils are on their way out does the resistance usually go up or down normally?? I just dont want to go and upgrade to a S2+ coil pack to find out that there is nothign wrong with mine atm :P

The resistance will vary a bit with temperature. From memory, changing the temp from 15 deg to 100 deg bumps up the resistance of copper wire by 50%.

[Defected]

if you can get ya hands on a vy pack chuck that on, I have a series 1 with a sv6 vy coil pack haven't had an issue since, will require building a bracket etc