Tech question:

1997 Lancer, 1.8L engine, 121,000 km.
Threw a CEL after a misfire whilst driving at 60 KPH, CEL went away after a while.
The misfire and CEL occur randomly, but only once warmed up.

I read on another forum the Lancer can throw a CEL from a misfire, so I changed the spark plugs, but haven't tried to drive it yet.

Haven't come across posts where a Magna or 380 doing the same, CEL on misfire. Can they do that?

Perhaps the CEL and misfire are symptoms of another problem? What is the ignition system on these motors?

CAS with 2 coil on plug setup.

The champions that came out looked to be running lean, also some corrosion on 2 of them where the plug tube connects to the spark plugs. NGKs in there now.

The only way, as far as I know, for an ECU to pick up a misfire is to have an oxygen sensor before the catalytic converter and a second after the cat and to compare the two readings. Haven't looked under the car yet for a second oxygen sensor.

i belive 1.8l uses Ignition Failure Sensor... these were common to fail on Galant VR4.

Basically it's the ECUs feedback to know that a coil pack has sucessfully fired. Symptoms are usually misfiring, unable to start, tacho not working.

either IFS or coil pack earthing/not working.

i belive 1.8l uses Ignition Failure Sensor... these were common to fail on Galant VR4.

Basically it's the ECUs feedback to know that a coil pack has sucessfully fired. Symptoms are usually misfiring, unable to start, tacho not working.

either IFS or coil pack earthing/not working.

Interesting!
Confirms my suspicion that this car can detect a misfire.
I had the coils off to change the plugs, so if it's a bad coil to earth connection, that should be fixed.
Are there any sensors for the IFS?

Update: worked out it is a small separate module. Where is it on the Lancer?

no idea... on the VR4 looks like a power transistor. plug has 4 pins.

On VR4, it lives on rocker cover - front bank of cyls. I'd say it'll be near the coil packs, as it works by measuring the voltage drop cause by a coil charging up (or something to that effect)

Although, it might not be the IFS - it may be a bung coil if it's able to work out if it's misfiring. IFS aren't cheap and hard to come by - so best to diagnose it to be that.

You can see it's signal output using an oscilloscope. you've probably got more luck finding a set of coil packs cheaper from a wrecker and starting with that.

Yes, located the little blighter. As you say, near the coil pack. On the lancer it sitting under the cam angle sensor on the passenger side of the head.
The following is a big help.
http://www.evoscan.com/manuals/ColtLancer96-0x/SUPPLEMENT/2001/16.pdf

I will run the car on the road some, to see if the CEL returns and take it from there. Thanks for your help!

I get misfire error codes regularly on my 380.

Codes P0301, P0303, P0304 etc.

I clear them then a few weeks later another one or two of them pop up. It's always weeks later, never just days later.

But no actual misfire that I can ever sense or feel, motor runs smooth as a baby's bum and always has.

I suspect these misfire codes are connected to my Chiptorque Xede piggyback and/or the O2 sensor error codes I get all the time (due to fitting RPW extractors and rewiring & relocating the two rear O2 sensors).

I stopped worrying about them years ago.

The trouble with a little engine like the 1.8L Lancer 4 banger is that a single misfire is really noticeable. Generally a smooth engine, but a single misfire makes me worry it may cut out altogether. And then I would have to WALK! (Shock, horror) Nah, all good - if it continues I will hunt down some ignition coils, and swap them over.

Well, sussed out the self diagnostics today, shorted out pins 1 and 4 on the OBD port. 16 pin "D" plug, which is I believe OBD2? Or is it 1?
(First time I've tried this, so fingers were definitely crossed lol)

Got error code 23, and no other. 23 is "Top dead Centre sensor fault", as far as I can tell. I assume this is the camshaft sensor attached to the end of the cylinder head.

Any way of checking this sensor without replacing it?

PS Are these the correct codes for a 1997 Lancer 1.8 EFI?
1 11 Oxygen sensor
2 12 Intake air flow sensor
3 13 Intake air temperature sensor
4 14 Throttle position sensor
5 15 ISC motor position sensor
6 21 Engine coolant temperature sensor
7 22 Engine speed sensor
8 23 TDC sensor
9 24 Vehicle speed sensor
10 25 Barometric pressure sensor
11 31 Knock sensor
12 41 Injector circuit
13 42 Fuel pump relay
14 43 EGR
15 44 Ignition coil
16 36 Ignition circuit

EDIT: pulled the TDC sensor out and measured voltages on the plug, 12V and 5V as per the manual.

Turns out this engine doesn't have an IFS sensor. What I thought was the IFS is actually the engine temperature sensor. (Hey! It's dark and cramped in there! OK? lol)

Problem still there, and very predictable each time - runs beautifully from cold, warms up, does a single misfire, CEL comes on. Turn engine off, it's then impossible to start even though the CEL goes off.

I'm looking for some new ideas, and some parts too. lol Ignition coil(s), camshaft sensor.

http://tech.mirage-performance.com/Manuals/Mirage%20Service%20Manuals/99%20Service%20manual/Volume%201/16%20Engine%20Electrical.pdf

Covers 1.8l - ignition system (coil pack checks, IFS, power transistors)

http://tech.mirage-performance.com/Manuals/Mirage%20Service%20Manuals/99%20Service%20manual/Volume%201/13B%20MFI%201.8L.pdf

Covers everything else EFI related.

ive had a few lancers through the shop with misfiring/cutting out and they have all been Cam angle sensor related
some times you can invoke the fault by gently flexing the sensor with the engine running.... gently does it though or you will invoke it permanently lol

ive had a few lancers through the shop with misfiring/cutting out and they have all been Cam angle sensor related
some times you can invoke the fault by gently flexing the sensor with the engine running.... gently does it though or you will invoke it permanently lol

Sounds like I'm on the right track then. This CEL shows up quite reliably as the engine warms up at idle, but flexing the sensor before it warms up may be worth a try and confirm it's cactus. Shorting out pins 1 and 4 on the OBD socket gives me 2 long and 3 short pulses of the check engine light, which is the code for the cam angle sensor, so that is fairly conclusive.

One link above suggests the cam angle sensor error can be triggered by a cam belt jumping one tooth, but pulling the top cover revealed a fairly fresh looking Gates 288 belt with proper timing. Not the problem then, but nice to know the previous owner did actually change the belt at the right time, which is something I've been a bit dubious about.

Car won't be needed for a month or so - meant to go to a female relative once she has her "P"s, gives me plenty of time to scour the wreckers, visit the Mitsu dealer or buy one from rockauto.com @$48 + whatever postage is.

Wife has a 2004 Lancer with the same engine electronics/sensors setup, so I consider this a valuable learning experience for when that messes it's nappy. lol

Thanks to all those who replied and posted links, without your help I'd be doing silly things like replacing coil packs, pulling apart the ECU and looking for blown capacitors, etc. lol

Update:
Went to Womma road U-pull-it north, found a pair of cam angle sensors for $15. (Looked for ignition coils, but none there)

Put one in, disconnected the battery while doing so to reset error codes, seems to have done the job. No CEL once warmed up. A decent drive down the road will tell . . . . I will pull the error codes, if any, some time down the track to confirm it is fixed.

90% of effort in fixing a car electronics problem is in the analysis, it seems. lol