VTS Running Problems

[oldmanmille]

Hi Guys, I'm new to this forum and also to the Saxo scene. Just bought a P reg VTS as I want to get back to trackdays having sold my Scooby RA a few mths back and I need something to tinker with and play!

This VTS has been played with such as straight through system (with the loudest 5inch back box on I have ever heard - horrible), Air Induction (Pipercross), head flowed and ported, 4 -1 manifold and the usual suspension mods. So as a base its got what I want.

However, there are running issues!

Idling is fine....

Low revs fine....

Slight load with light throttle it misfires - coughs and spluts but pulls extremely well...

Heavy throttle goes like stink....

However, was on motorway just, accelerated and then power dropped off and felt as if on 3 cylinders but car then accelerated, albeit slowly, and I sat at 90mph for the next 30 miles non stop. Still sounded as if on 3 cyls and exhaust note distinctly subdued!

Came to the junction to come off and the car idled and stopped. Took two attempts at the key to start and when firted up a big lume of blue smoke and I noticed the temperature guage went to red and sat their with its light on for a few seconds (that bit might be normal as a start up sequence I assume).

Once car started it pulled away like a rocket on full cylinders and up to 120mph within no time (my Lexus RX behind also recorded 120 on the road angel so I know correct) - yeah silly I know but on a clear stretch with no issues weather wise etc.

5 miles at this speed and then pulled off onto A roads and again exhaust note subdued and back to 3 cyls although probably not actually 3 cyls but hopefully you follow my drift!

Pulled in to home and car cut out. Not restarted as had to get back to work.

So, anything in the above that sounds familiar?

Is it plugs? Coil Pack? Lambda Sensor? ECU?

Any assistance would be gratefully received as I would like to get this onto the track pdq so I then know what else is needed apart from cage, seat/s etc....

Thanks in advance,
John

[oldmanmille]

Forgot to add that appears to be over-fuelling as strong smell of fuel smelt from my mate following me ! Also used a lot of fuel on motorway - abnormal for 90mph running in a little 1.6 :-)

[oldmanmille]

With no replies am I to concude that the experts are on holiday or is it simply nobody experienced any of these problems?

[Gabbastard]

Id check your plugs first, will tell you if the engine is overfuelling or burning oil regularly. Might account for the shite starting.

Seen coil packs go before and lead to affected acceleration and changed exhaust note, but they tended to sound like Impreza impersonations, very burbly.

The fact its occurring on light throttle might point to throttle position sensor, but when mine had damp in it it seemed to cough and fart above about 40-50% throttle.

The symptoms would make me think a couple of things, but no one thing is obvious by what youve described.

[oldmanmille]

Much appreciated Gab, my thoughts also so will proceed down those lines. Had similar with zetec s and changed coil pack leads and ended up just plugs so will start in reverse this time lol.

Just thought it may have been a common issue with these. Got a big oil leak now so that next on the list. Good job I wanted a hobby lol

Thanks again

[Gabbastard]

Let us know how you get on, be interesting to hear what caused it.

[oldmanmille]

Taken plugs out and look fairly reasonable but will replace anyhow. However, when getting to the coil pack it was loose, only 3 of the 5 studs in and one of them hadnt been tightened!!

The small pipe from thr head to the throttle body was split. The pipe from the crankcase to the head was also split - found the source of the oil leak at least!

Replacement Coilpack located off ebay just in case this one is goosed. Just need to find some screws now.

Also found a hol in the air induction feed pipe and assume it had a sensor in there at one time but no sign of a sensor lurking anywhere so new pipe to be sourced.

Once I have things I will try again and see what it goes like. Wish I had got a standard un-touched one now as have a feeling this gonna get messy!