Car Is Surging And Other Problems

[EXR6T]

Started the car this morning and unlike every other time I have started it the car began to rev itself up to 2k revs before I turned it off and started it again.

On the way to work the car was surging while accelerating, so while I was giving it normal acceleration it would feel like I pushing my foot up and down on the pedal lightly. wasnt lacking any power though. The surging is not really bad, and feels more like its getting more power than less power. The engine light was on while driving to work I didnt realise until I got to work, but I turned the car off then on at work and the engine light went away.

On the way to get lunch the car was still doing the same, but while accelerating I heard a loud clunk and the engine pretty much almost cut off (stalled) it felt like it was running on 5 cylinders or something (REALLY ROUGH), no accelleration what so ever when I tried pushing the pedal down a bit, I quickly pulled over and turned the car off, then I started it back up and it was okay but still had the surging while accelerating.

The other thing I noticed is that while accelerating there is no slow down when staying in gear and backing off the throttle, if anything it feels like it is accelerating more. Its a T5 manual, and normally like manuals do if I accelerate to 3k revs then back off the pedal without changing gears it will slow right down like braking but with the gears. When I did this it felt like it was actually accelerating more when I backed off the throttle. even when I did it going up a hill the car sped up.

Any idea what this could be and what it could cost to fix? there are no reputable tuners down here in Tassie, and I am yet to find a reputable mechanic either since moving down, so any help would be appreciated.

I was thinking fuel pump. The car has almost 200,000 kms on it so its a pretty old beast but has been well looked after, I doubt the fuel pump has ever been changed by the previous owner.

[millers]

could be throttle body? maybe fuel filter? has it only just started doing it? you may have got some bad fuel

my car has the surging thing atm too. I have changed plugs, coils and fuel filter. after checking AFRs it is leaning out in top end (on stock tune) so next up is fuel pump :(

[EXR6T]

yeah it only started doing it this morning,

was fine on the way home from work tonight though, which is strange, seeing it was bad on the way to work, terrible on the trip for lunch, but fine on the way home, I even gave it a little squirt and power seems unaffected.

Tassie fuel is pretty damn bad so it wouldnt surprise me if it is just a bad batch of fuel, but I filled up the tank this time around and it is down to half way before it started doing it, might chuck some injector clean in just in case. But from memory of getting bad fuel before it doesnt quite feel the same as last time.

My car is custom tuned. I might flash the stock tune in it for a while or at least until I sort this out.

[millers]

stock tune might not like the mods you have.

is it an xcal 2 or 3? if so it can read trouble codes and do some data logging with the SCT LiveLink (I think) software. might help track down where the problem is

[ratter]

your car will overboost with the standard tune back in because of your 12 psi actuator

[RAP1D]

I'd look at the intank fuel filter first, then plugs, cat...get the basics sorted.

It could be a cheap fix if, who ever is working on it finds the problem straight up.

[EXR6T]

Yeah I kind of thought that overboost would be an issue so I flashed the low boost / economy tune (95 ron). I only have the ford flasher not the xcal thingy.

the problem is I dont really have anyone working on it because I dont know any good mechanics down here in Tassie yet and there are no Tuners as such for these cars (only holdens from what I've been told).

F6T recommended I try Howell Automotive so I might give them a call, I spoke to them about my diff bush previously but wasnt filled with confidence when they swore black and blue that the XR6 Turbo does not have a diff bush and told me I was referring to control arm bushes. I may have just got one of them who was not familiar with these cars though, as im sure that happens a bit. F6T says they are good and to speak to someone else there so I'll give that a shot.

Just drove it down to the shops after flashing the low boost tune and still seems okay, no signs of anything wrong, maybe it was just something in the fuel line? I'll see how it goes for the next few days.

Of all times to find another modified XR6 turbo I pull up to one when I have my low boost tune in and my car goes like a N/A. It's like the first time in Tassie I have pulled up next to a modified XR6 Turbo and it's when im having dramas ... *sigh* Damn murphy and his laws