Greetings.

I am going to come clean as a some time lurker here. I'm an active poster on Club-VR4, but there's not much GDI-specific knowledge there, so I've come to you...

I have a 2001 (X-reg) Galant GDI Elegance (UK Spec). For some time I have had some issues with the engine, and have tried a few things...

The main issue is a hesitation and "stumbling", jerking on light throttle acceleration, particularly up hills. Also, when going along on constant throttle setting sometimes the car suddenly reacts as if the throttle has been pressed a little more.

So, what have I done so far? First off, I've been trying to tackle the coke. When I bought the car the oil was black. REALLY black... I changed it as soon as I got it home, and have been running very short interval changes (1500 miles for first two, then 3000 since) to flush some of the junk out - on the third change the oil came out reasonably clean, unlike the first two. I'm currently using halford's 10W40 "fully synthetic" (I know it's not really) for the short change duties, and will be going to Amsoil 5W30 once that's completed.

In addition to that, I've run a can of 10k Boost through the car, multiple tanks of injector cleaner additives (redex, STP, Comma D-Tox, etc).

I have changed the spark plugs, although the previous set were ok when I took them out (I've kept them as spares).

With all that done it was still doing it, and came to a head one day, with a serious jerk when travelling along at constant speed, and then out of the next roundabout no power, and the engine check light came on. I nursed the car home, plugged it in to the computer and got P0304 Cylinder 4 Misfire code. From looking on here, I found an issue with 2.4GDI Chariots of the spark escaping the coil pack where the insulation breaks down, and so I went to work with some insulation tape. Wrapping the area of the coil where it sits on and passes through the inlet manifold in tape seemed to fix things - cleared the code and the car has run smoother.

The problem is still there though, it's just less bad. I taped up the rest of the coils, but that made no difference.

I have subsequently also cleaned out the throttle body, which was somewhat cokey, and the butterfly seemed not to be able to properly close. Now it can and can move more smoothly, but again, it doesn't seem to have made any difference to the issue.

So, I am thinking that the coil pack wants replacing. Mitsubishi UK seem to hold an unusually large number in stock, which suggests they are problematic. At £117+VAT each, I am not inclined to replace 4 (at around £550). The part number the dealer gave me was MD365101

I have been looking for alternatives and come up largely blank, except for this: http://www.ignitioncoil.co.uk/Products.asp...GDI)&e2=4G64GDI

This suggests itself for the spacewagon (chariot) 2.4GDI, but not the galant. The cross reference part numbers do not include the above part number that the dealer gave me. However, both are 4G64GDI engines, both using the same spark plug (IZFR5B), etc... how much difference is there? Is there any chance that this part might work in the galant? It would work out at around £150 saving on 4...

Any insights welcome!

Hi,
Greeting from the tropical Far East!
You didn't mention clearly when it was that you got your Galant, and the mileage it's clocked. Let me just share my experience:
When i first got my Chariot 2.4GDi back in Aug 2003 - a reconditioned '99 unit from Japan - i was pampered by its near-magic carpet ride. Before long, problems arose, most annoyingly the sudden jerky drive train for 3~6 seconds during around-town ride @ 40-60km/h, sometimes @ 80-100km/h. I just needed to deccelerate and it'd go away.
(is this what's bugging you?)

It started me hopping from one workshop to another looking for solution. I replaced the engine mounts, gear oil, spark plugs, but they all didn't solved the problem. One mechanic suggested that i replaced the drive shafts!
Luckily i didn't follow that advice.... After searching around for 3 or 4 months, finally found the answer in this forum: it's the gear oil - the ATF!

The first try of gear oil change didn't work becoz atf of wrong grade - and wrong brand - was used !!! After a refill of six litres of DiaQueen ATF SP III, the smooth ride was restored - yes!

So there you go - try flush the ATF, and insist on using genuine MITSUBISHI DiaQueen SP III ! Isn't your car a Mitsubishi ;-)
cheers

Best regards,
Chung

p/s - my Chariot is still bugged by noisy tappets. Any advice ?

An update...

Yes, that description is what is bugging me. However, my car (which I bought in june, about 82000 miles now) is a manual so it's not ATF - However, I did have ATF issues in my previous galant (8g 4G63 auto wagon) and found that problems were caused by bad dealers in the UK (used Dexron III and didn't flush torque converter, cooler, etc) and undercooling of the ATF system in the galant (the "cooler" consists of a single pipe) causing the ATF to rapidly degrade. In my old galant I used Amsoil ATF which was a revelation - smooth, cooler running, better MPG and after 20000 miles still looked like new. Amsoil is SP3 compatible, but is fully synthetic - runs cooler and lasts longer.

Coming back to my problem, I've been testing a lot of things... O2 sensor output seems correct (logged through tactrix cable), but I'm leaning toward a combined spark and EGR issue now. I will clean out the EGR valve when I can get it off (the screws are hard to get to).

On the coil packs, I bought one of the Spacewagon coil packs, but it did not fit - the length and sparkplug fitment were both correct, and it fired the engine fine, but the mounting holes are in different places.

I have now ordered the correct mitsubishi MD365101 coils through RHDJapan - at a total of 30000 Yen - about the price of a single one in the UK.

I may get the injectors professionally cleaned also - hoping that between coils and fuel injectors it should get back to running smooth.