Hi All,

As stated I have a 97 VRG Galant (4G93 1.8L GDI), Lately whenever I've been driving it around for long periods it starts to lose power and judders (Exhaust sounds like pop pop pop noises). I took it to my local mechanic and they ran a diagnostic on it and it came up with "No. 4 Coil Pack Problem" I bought a new coil pack and I assume I replaced the right one.

Left to right on engine there are 4 Spark Plugs with coil packs on top, I replaced the 4th one (being far right), but it is still doing the same thing. I'm now wondering if the machine meant Firing Order , Therefore I should of replaced the coil pack that is last to fire.

I have no idea and the mechanic is closed for the weekend, which is also the only time I have off to work on this stuff.

It only does this when it's been running at peak operating temperature for extended periods of time. the Rev counter shows it's still revving normally, but accelerating slowly and I sometimes have to manually change the gear myself (Triptronic).

Any help appreciated.
Thanks :)

check to see if your knock sensor is still good it adjusts your timing in accordance to engine temperature and oil levels. maybe you just need some more oil and your knock sensor is changing your timing to far ahead causing back firing. the pop pop pop is a back fire with a catylitic converter on it. not as loud as they are with no cat. so i would check your IAT sensor, your knock sensor, your MAS and your oil. if it is not these then your ignition failure sensor may be going bad. basically all it should be is a $30 2 bolt sensor switch.

Can I tell if they are bad without any special equipment, or do I need to take the car to a mechanic?

Thanks :)

Edit: Ok I can't find the Knock Sensor anywhere, all the manuals I've looked at have the layout for the American or NZ New Engines not the Japanese versions, Anyone know where to find it on the above car, Model is EA1A

Updates

Took it to another mechanic, they checked everything and said it was Missing on all cylinders, suggest a fuel pressure test

So i took it to Mitsubishi This is what they said:
Plug in MUTT and check for codes, Check Data listings Inc charge rate, check fuel pressure All OK, Fit new plugs still missing, Supply and try 2nd hand coils, still missing.

Suggest Injectors and Bucket Filters and Manifold Cleaning and Replace Coil Stalks
around $2500 for the "Suggested" bits.

Definately "Misses" on all cylinders while accelerating under peak operating temp, I don't think it's the coil stalks or it would of run better when they swapped the coil packs.

Any other suggestions from you guys? I don't wanna pay $2500+ for something that might or might not fix it.

I can get a set of 4 injectors for about $170, Probably better than sending them off to be cleaned, Not sure about bucket filters or even if I can clean the manifold myself.

Thanks