Mathias0487

Have an 2000 type r that is standard bar a hks exhaust system and manifolds and apexi air filter.

It has a misfire under load on boost, it only happens now and again however misfires and splutters quite badly.

The leads and coil look to be ok, however on checking the maf today I found that it was loose, after removal I found this below. I refitted it and made sure it was secured so it couldn't move, tested again but the misfire still present.

Any ideas?!

Peter Pan

iTrader: (6)

Sounds like a shot MAF to me, I had similar symptom's. I'm sure someone will be along shortly to correct me if I'm wrong though, has the car been mapped for the mods your running??

Mathias0487

I've also just read that if the speedometer isn't working then at 4500 rpm you'll get a misfire / splutter due to a safe mode?!

Is this right as my speedo isn't working?

Peter Pan

iTrader: (6)

If that's the case then there's your problem.

Mathias0487

Ok cheers mate hopefully someone can confirm!!

Crowman

That's correct, the ecu loses the speed signal hence going into safe mode .
Assuming it's the same as earlier impreza's , as I had this some years ago on my 1997 WRX v ltd .

Mathias0487

It's a w reg v6 type r so I'm not sure!

What did you replace to fix the speedometer?

Crowman

I replaced a broken speed converter, it was a mechanical one on my WRX but they are electronic on V5&6 i believe

Mathias0487

Converter changing the reading from km to miles you mean? Where was yours fitted? Behind the cluster? I have to take the clocks out to replace a bulb anyway so I'll have a look then!

Do you know if the v6 I have would still splutter at 4500rpm ish as the earlier models do?

Crowman

Yes that's what I mean, mine was a mechanical converter near the gearbox , on the earlier classic it fits between two parts of the speedo cable .

I'm 90% sure the ecu will go into limp mode on later versions the same and drop the boost and limit the revs to around 4.5k if the speed signal is lost .

I'm no expert , and I'm sure someone else will know for sure

Mathias0487

Ok thanks! Think I read the newer models without the cable will have an electrical converter on the back of the cluster, maybe a bad connection or it's become faulty. It does work occasionally so maybe a poor or loose connection!

Thanks

Mathias0487

Will this cause it to misfire always at 4500 rpm as just driven it and gone to 5000 plus no problem

Crowman

I thought when in limp mode it put a cut out in at 4.5k and lowered boost

Mathias0487

Hmmm....

It's happening lower than 4.5k, sometimes around there and sometimes boosts just fine. Maybe I have two problems. Ill try and sort the speedometer and go from there I suppose

Mathias0487

Right removed the cluster and only 3 multi plugs behind there, no converter to change to mph. I needed to change a bulb behind there anyway. This is what I found, all looks to be ok. Worth cleaning the mutiplug nearest the speedo and using some electrical grease / spray?!

Mathias0487

Anyone have any idea?

Mathias0487

Going to check the wiring for the speedo in the morning, however just driving it now. I accidentally turned the parking lights on via the top of the steering column and the speedo flickered up to 40 then back down and went back to not working. Would this suggest the wiring has an issue or not?

Crowman

Hi.
Certainly sounds like a wiring type issue you have.
Strange one for sure

Mathias0487

It is strange, as said the speedo flickered when parking lights switched on, but then when switching the lights off and on again it didn't move.

I'm assuming the wiring goes up from the sensor in through the bulkhead? Any way of checking it other than visually? Can I check power anywhere as I'm guessing its not getting power at the multi plug due to it not working?

I don't want to remove the speed sensor from the box until I'm sure it's that really

Mathias0487

Is this the speed sensor? Pictured on the right with wiring coming from it out of the box?

Can I get to that from the top or easier from underneath? Ill check for broken wires first but I'm assuming that as long as I get power at the sensor then the sensor is faulty?

Chocador

iTrader: (3)

I have an identical v6 ltd and my mag looks similar to yours,my speed limiter is cleverly soldered into the detachable gearbox loom under the sheathing,take it off and pull back the sheathing to hopefully expose a small box with 3 wires,hopefully its a bad joint or something easy.

Mathias0487

Ok thanks for the info!

Crowman

Any luck ?