2.4 (4G64) GDI - Idle Problems

[swinks]

From described symptoms:
100% electronic actuator of tps in throttle body. Common failure claim hundreds times on Polish forum Mitsubishi owners.
Only reconditioning. Don't know anyone doing that in UK. We have one forum user in PL who is doing homemade reconns.

[Rambaud]

Like I said, I don't think the valves are really that dirty, because when I had the intake manifold off, the carbon coating seemed to be very minimal at the ports, therefore the mechanic did not deem it worthwhile to clean in further.

Also, I'm not one of those people who likes to try and keep the GDI light on. It is infuriating to drive that slow. I usually drive in tiptronic mode and change gear at ~4k RPM. My mum has been known to drive it like that though and she got fuel economy of around 7.5L/100km!!! I get around 8.5 on long trips.

Long motorway trips give me ~ 6.73L/100km - that's fully loaded plus aircon.

I would think ~ 5.65L/100km might be possible with cruise control and less weight.

[bradc]

Remember that your car is a Galant with 2wd whereas Ryan's is a 4wd Legnum so according to Mitsi japan's specifications you will do 7.7l/100km and he will do 8.7l/100km. Apparently a 4wd ST-R will use 10.2l/100km on the same test cycle and a manual one will do 9.4l/100km

Which would mean for a 4wd Legnum it would cost you (at today's prices) to travel 1000km:

5MT ST-R = 94L at $1.81 = $170.1 91 octane
4AT ST-R = 102L at $1.81 = $184.6 91 octane
5AT 24GDI = 87L at $1.96 = $170.5 98 octane

[ryanjames.powell]

Mine's not 4WD, its 2WD. And that fuel economy includes some city/town driving as well. It's an average over the whole tank. I don't know how much it actually uses when cruising as I don't have any means of reading it.

[Johny]

mine would be lucky to do 10l/100km
you guys are lucky lol

[bradc]

ok, so it is 13km/l for an auto 2wd 2.4, so 7.69l/100km

[ryanjames.powell]

Well anyway, back to the topic, I was hoping to get the car back this weekend, but the parts didn't arrive til this morning (what does that say about how many people need new valve seals?). I went to see how it was going this afternoon, and he has decided to take the head off after all, so the valves etc will be decoked before it goes back together. Out of curiosity, is the head gasket a steel one?

[swinks]

IIRC, yes, multi layer.

[ryanjames.powell]

Head's being put through the cleaner today. Apparently there was a fair buildup on top of the pistons from all the burnt oil, and the exhaust valves were a bit caked up too.

My rings and bores are in excellent condition, you can still see the markings on the inside of the cylinders from the factory (Not very much wear). So sounds like it won't be too expensive...

[ryanjames.powell]

Just had a conversation with my mechanic on the phone, they should be able to start it up this afternoon and I should have it back tomorrow!

He said the exhaust manifold was soooo full of crap that you couldnt get your little finger into the holes, so that is probably a big part of why it wouldn't idle properly...

[ryanjames.powell]

From described symptoms:
100% electronic actuator of tps in throttle body. Common failure claim hundreds times on Polish forum Mitsubishi owners.
Only reconditioning. Don't know anyone doing that in UK. We have one forum user in PL who is doing homemade reconns.

Have already tried replacing the entire throttle body, so that's not it. I also had my original reconditioned and it's now back on the car.

[ryanjames.powell]

OK, I have the car back, and it is, unsurprisingly, slightly faster to accelerate.

BUT - it is still idling at ~500rpm...

Any more suggestions? Sensors?

[VR4WGN]

throw it away?honestly ida removed it and put an actual engine in it already!!!! but thats just me and m,y opinion on 2.4 CDI(CRAP-DI)

[ryanjames.powell]

throw it away?honestly ida removed it and put an actual engine in it already!!!! but thats just me and m,y opinion on 2.4 CDI(CRAP-DI)

I actually think now that it is not using oil and isn't clogged up, it is basically as powerful as the 2.5 V6 and the fuel economy is a hell of a lot better than a 2.5 V6. I can put up with the low idle as it isn't a real problem, just an annoyance. I was just seeing if anybody had any ideas as to how I could fix it without going to too much expense, but apparently nobody does (or they don't care because it isn't a VR4 ).

[bradc]

It isn't that noone wants to help, it is that we don't know the answer! The V6's have a mechanical idle control so it is very very easy to do. If I'm honest the only thing I can think of is drilling a 2mm hole in the middle of the throttle butterfly to let a bit more air come through at idle and see if that makes any difference. If it does, just drill out to 2.25 or 2.5mm to get it to exactly where you want it.

I have NO IDEA if that would help, or make it worse but if you have a spare throttle around it is an idea at least I think Quinton should have a few spare throttles!

[PRLWHT]

I have a GDI and have the same idling and oil prob... Ive found that that if i take it for a good run at 100 in 3rd the engine frees itself up a bit. the other thing i do is regularly use injector cleaner. I also get my plenium acid bather fairly regularly. I also noticed that when i was stuck n traffic on a trip to auckland that my oil light was going on while idling. as soon as i raised the revs to 800 (foot on accelerator) the oil light went off, any ideas what could cause this? it only happened once when i was moving about 200m every half hour.

[elnevio]

I also noticed that when i was stuck n traffic on a trip to auckland that my oil light was going on while idling. as soon as i raised the revs to 800 (foot on accelerator) the oil light went off, any ideas what could cause this? it only happened once when i was moving about 200m every half hour.

Low idle + hot oil. What grade of oil are you using? A slightly heavier weight will probably help. E.g. I am aware of the odd VR-4 that will have the oil light flicker when at low idle, but a change from the fairly commonly used Amsoil 0w-30 to their 10w-30 fixed that.


@ Ryan - It might be worth resetting the ECU (if this has not already been redone). It might need to relearn the idling as it has been clogged up for ages. It's free and easy!

[PRLWHT]

[QUOTE=elnevio]Low idle + hot oil. What grade of oil are you using? A slightly heavier weight will probably help. E.g. I am aware of the odd VR-4 that will have the oil light flicker when at low idle, but a change from the fairly commonly used Amsoil 0w-30 to their 10w-30 fixed that.


Im using castrol 15W-40

[ryanjames.powell]

@ Ryan - It might be worth resetting the ECU (if this has not already been redone). It might need to relearn the idling as it has been clogged up for ages. It's free and easy!

Good idea, but the battery was disconnected for about a week while the mechanics were cleaning it out and replacing the valve guide seals (which were apparently "like bakelite"). So the ECU has been well and truly reset. I also find that it will learn on the fly too, ie it doesn't have to be reset, it constantly adjusts itself. I found this when I decided to adjust the APS to up the idle speed a bit. I drove about 5 minutes and then stopped and it had compensated for the change and gone back to the bad idle again.

[wintertidenz]

Reset the ECU, start up the car when it's cold and let it run with the air con on for 10-15 minutes. Restart it if it stalls, and see if that helps.