Thread: Help with misfires

Have you checked for air leaks?
I seem to recall getting misfires on the old D2 V8 after some work as the vacuum hose for the brakes was leaking.
I've also had the O2 sensors go and I'm pretty sure you actually get an O2 fault but perhaps it depends on how it fails. The thing of note is that once it goes open loop the O2 sensor was not an issue, IIRC about 1500 rpm was the switch over to open loop.

Originally Posted by steve_a

Have you checked for air leaks?
I seem to recall getting misfires on the old D2 V8 after some work as the vacuum hose for the brakes was leaking.

I'll have to ask about this.

Originally Posted by steve_a

I've also had the O2 sensors go and I'm pretty sure you actually get an O2 fault but perhaps it depends on how it fails. The thing of note is that once it goes open loop the O2 sensor was not an issue, IIRC about 1500 rpm was the switch over to open loop.

I'm getting a choking feel through the pedals at all sorts of different RPMs, but mostly when I'm decelerating or sitting at a constant speed (It's worst at about 65-70kph)

What type of leads are you running? I use absolutely nothing but OEM resistor leads, other types are notorious for running erratically. Roverlord sold me the last two sets and they run very much better than what came off.

Originally Posted by bee utey

What type of leads are you running? I use absolutely nothing but OEM resistor leads, other types are notorious for running erratically. Roverlord sold me the last two sets and they run very much better than what came off.

I'd have to assume Bosch as everything else that's gone in has been Bosch.

Originally Posted by s7000

I'd have to assume Bosch as everything else that's gone in has been Bosch.

I'm not aware of any Bosch leads available for a THOR setup. Coil packs and plugs for sure but not leads. Also, Bosch plugs are now being made in Russia and I no longer recommend them for coil pack systems although they still work fine on distributor systems.

https://au.bosch-automotive-shop.com..._keyNumber=50#

Click the "engine" tag.

Try some other plugs first, e.g. NGK, then call Roverlord and get some of his leads.

Originally Posted by bee utey

I'm not aware of any Bosch leads available for a THOR setup. Coil packs and plugs for sure but not leads. Also, Bosch plugs are now being made in Russia and I no longer recommend them for coil pack systems although they still work fine on distributor systems.

https://au.bosch-automotive-shop.com..._keyNumber=50#

Click the "engine" tag.

Try some other plugs first, e.g. NGK, then call Roverlord and get some of his leads.

Don't know the brand... But it's a 7mm wire...

I'd hazard a guess it should be an 8mm, as per most of the discussions I've been reading.

Originally Posted by s7000

Don't know the brand... But it's a 7mm wire...

I'd hazard a guess it should be an 8mm, as per most of the discussions I've been reading.

The thickness of the insulation is irrelevant. It's the conductive core of the lead that counts. Some of the most reliable OEM leads on other vehicles I've worked on are 5mm in diameter. Air is as good an insulator for magnetic fields as rubber, so spacing leads apart is more effective than thick rubber covering.

Originally Posted by bee utey

The thickness of the insulation is irrelevant. It's the conductive core of the lead that counts. Some of the most reliable OEM leads on other vehicles I've worked on are 5mm in diameter. Air is as good an insulator for magnetic fields as rubber, so spacing leads apart is more effective than thick rubber covering.

In that case, I'll need to double check. They look like this though...