Power loss then power back again

[Mr T]

If I remember correctly, Boost is set to 0.6Bar with a 10 second over-boost to 0.8Bar for help in over taking.
The boost reading should be quite steady. Maybe you've got a boost leak, I have heard that the bottom corner of the intercooler can wear where at mounts. Might be worth a poke around.

[Minigirl]

My actuator has been bodged someones snapped the pipe off and bonded some copper brake pipe in. I wonder if thats causing the wastegate to open and close fast making the needle flutter?

Trying to upload a image but the site wont allow it, its the pipe closest to the actuator arm


Changed the top ht leads, the centre lead left broken pieces from it in the coil pack and the nipple inside the coil was covered in blue corrosion... Maybe this is the issue?? Cleaned the corrosion out and fitted the new leads.

Oh, who the hell thought putting the leads in like that was a good idea??? Remove the inlet manifold and fuel rail etc to change 3 spark plug leads??!!??

[heinkeljb]

What you do is tie a piece of string to the old lead and when you pull it thought the string follows the path. Tie the string to the new lead and pull it back through. No need to take the manifold off.

John

[Thrumbleux]

Twin plug per cylinder engines have their own risks. When operating correctly, combustion commences simultaneously from both spark plugs. If one plug is inoperative due to duff lead etc, combustion commences from only one plug. By the time the flame path has made its way across the chamber to the mixture that the other plug should have ignited, there is a risk that the unburned (as yet) mixture spontaneously detonates due to heat and pressure (knock). The detonation (knock) sensor if it detects this will cause the ECU to take measures to curb the detonation for the safety of the engine. Boost reduction and retarding the spark timing are the usual measures - both of which will cause a drop in power.

How rapidly the boost 'cycles' when the above occurs I do not know (but detonation prevention is an iterative process where the adjustment is made in the direction that curbs detonation and then in the other once it is curbed and back again if detonation is again detected, etc, etc) but the fluttering you are seeing on your boost gauge may well be evidence this process occurring.

[Minigirl]

Aahhh the guide I read said to remove the manifold due to restrictions at getting to the coil to remove and replace the lead...

But I suppose if i didnt remove it i wouldnt have got a good look at them and saw the corrosion and the bits of spart plug lead broken off in the coil...

Still got the problem, running fine zoomimg along at 60, stop after 5 mins, pull out onto another 60 road and get upto 45 fine just 45 - 60 takes a while then drops to 55.... Then stop again, do 30 for a while and enter a 60 and it zooms along with no problems, until you hit an incline / hill starts dropping in speed when ot shouldn't but get off the hill and go down it and its fine again....

Thinking of ordering a coil or 3 coils to change them all. Wheres the best place to get then from? Euro car parts have them but HAAS brand and £43 each with discount or is that the going rate?

Thanks

[Minigirl]

Drove home today with no issues... The usual hill the slows me from 60 down to 50 in 6th was no issue, went up it at 45 in 6th with no loss of speed at all...


Suppose its a good thing as well if its intermittent and not all the time, at least its not internal, surely if it was internal engine problem it would be happening all the time...

[Minigirl]

Haven't managed to sign up to the other sites yet but i replaced the middle coil that had blue corrosion on it with a new bosch coil and it was still the same :-(

So swapped the left side coil with the one i took off the middle and there seems to be an improvement :-). The left coil is a Bremi so must have been replaced in the past.

Still have the problem but the car seems to be able to sit at 60 now while doing the problem instead of dropping to 50...

I wonder if maybe 2 or all 3 coils are on there way out?

Ordered another anyway to fit and see how it goes

[Minigirl]

Stuck another new coil on on the right closest to the dipstick and the car is running the best it has for ages.

Done a 30 mile nonstop journey at 60 - 70 mph and the problem only happened once for just under a mile but it was a much more smoother rumble with no real loss of power (unless i was on uneven road and it was tyre vibration / noise)

Middle and right are now new coils

[Minigirl]

Not getting over excited just yet, will give it a few drives first

Hopefully the mpg goes back up seem to have dropped 50 miles worth of fuel per a tank

[Minigirl]

Are the fuel filters known for clogging up on smarts?

Thanks

[heinkeljb]

If it has never been changed before, then it is worth changing.

John

[Mr T]

I remember a few years back on one of the forums, somebody managed to fit their fuel filter back to front & that caused all sorts of problems.

[tolsen]

My 450 has clocked 260,000 km and I have only replaced fuel filter. Original filter developed a leak in its cylindrical area due to corrosion in way of contact with its support cradle. Replacement filter had improved corrosion protection in the form of plastic film around cylindrical part.
You can easily testi your filter by blowing through it by mouth. In my opinion, these fuel filters should last as long as the car unless they develop leaks.

[tolsen]

Replaced only once.
This forum is hopelessly slow.

[Minigirl]

Its running alot better with the 2 new coils, done 60 miles yesterday and today and it only did it today when I tried to go 70mph.

I wonder if all 3 coils were on the way out? Might just order a 3rd new coil....

Oh another thing what should the spark plug gap be on the 700cc smart? I fitted 6 new ngk plugs but didnt check the gaps or are they usually pre gapped?

Thanks