In another thread I mentioned I have a severe loss in power at around 5,000rpm under heavy throttle but comes back on again nearer 6k and then drives normally, although sometimes even in the upper revs I can sometimes feel hesitation...I thought this might be due to a faulty fuel pump! However I'm thinking now perhaps a Coil Pack after reading on some other forums!!!

I had a couple of mechanics try to test the car with code readers but they couldn't communicate with the car on two different systems! So that didn't help!

I had a look at the spark plugs and they look ok, but got new ones coming! One of the coilpack feeds (The tube that connects to the sark plug) was a bit dirty compared to the others but wiped it clean! Is there a way for testing the firing of the coilpacks?

Or....another possibility after disconnecting the code readers my Trac and Engine light were flashing at standstill but dissappeared once I started moving! After restarting the engine it didn't do it again!! Could it possibly be a faulty speed sensor throwing the signal?

Any help would be greatly appreciated!!!

not sure how you test them, dunno if you can do it with a meter at all, you could try talking to westover toyota to see how they test them if not I've got 4 coilpacks at home your welcome to try swapping them all over to see if that make a difference.

Yeah, called westover and they want silly money just to look at the car! Plus silly money per coil pack!!

Just thought there maybe something I can do!!

I'm going to stick new sparks in to see if that does anything to help! Appreciate your offer and if I don't find a solution soon i'll be in contact to pick them up to test them!! Cheers

get one good coil pack and mark the top with paint or somethin so you know its the new 1..

then take the first one out and put the new one in...

test drive the car and see if it makes a difference...

if not then continue on with the other 3 cylinders until you find the one thats gone.

had the same problem with mine a few months ago. the coil was breaking up and only acted up at about 5000rpm

Yeah sounds like it could be a coil pack then!! Did it make any other noises at all? Mine doesn't do anything just backs off agressively under throttle at 5K....the weirdest thing is sometimes it doesn't!

Robin...when can I pop round to try a pack?

You say one of the coilpacks was dirty, was it sort of oily? If so it is probly that coilpack, i would try robins coilpacks if i were u. Also with engine light it was probably just on where you were trying to scan it. You can scan them but not with the majority of scanners/code readers as they work on european OBD whereas cos altezzas are jdm they work on japenese OBD. i do know someone in the ferndown area with a scanner that can talk to them i dont have his fone number but his name is barry grimmit

No, none were oily...one had some brown dusty stuff on it...more like dried rad fluid but obviously not actual fluid residue, or I would be really concerned!

Does there have to be oil to be a sign of failure? Surely if it was electrical it would just be inside the plug rather than discharge oil?

I'm going to try Robins packs as a test! Timo if you could get a contact for Barry that would be awesome!

Cheers lads

No there doesnt have to be oily residue on a failed coilpack. you often find they are oily or have an oily residue on them when they have failed as they have oil in them. i will ask him next time i see him, i expect i he will be in with an mot sometime next week.

OK update...tried one of Robins coilpacks on all cylinders to no effect

Still can't find a suitable reader either I did have the car booked in september to Read and get them to dyno test it and check fuel pressure stec but the only date avaialble is the same day as the MOT!!

Next option is to check the voltage of the TPS and give the MAF and throttle body a good cleaning again, then check fuel pump voltage and then who knows what!!!

Does anyone know if the throttle is a fly by wire? I read somewhere that perhaps the throttle sensor is linked to the wheel speed sensor and if that's dodgy it can cause throttle issues!!!

why dont you just take the car in for mot at an earlier date? (ps im an mot tester on ferndown industrial estate). i personally wouldnt take my car to read either but thats only my pesonal opinion. Just a thought, have you had the oil changed recently, your not using realy thin oil are you?

Yes oil was changed recently to 5 - 30w Fuchs Fully synth Pro S it's OPie suggested!!! I noticed a bit of hesitateion this morning at around 3300k when it was cold and under fairly heavy throttle!!

The other thing I have noticed is it does take a bit to start the car initially and flutters for a split second before idling of which is then stable! Dunno if that's related!

Read performance suggested an air sensor of some kind or fuelling!

Does anyone have a diagram for the OEM plumbing of the pipes going into the airbox...the little ones...I did disconnect them when I first got the car but i'm 99% sure they are back where they are supposed to go except the one that lowers the flap in the intake! (I did re-plumb this already but didn't make any difference except noise)