Baffling problem

Hi all sorry for the long post,
Hope someone may be able to shed some light on this one for me Volvo have no answers,i have an intermittent problem when i accelerate hard up through the gears 2nd gear at 5,100 rpm aprox power just dies with a puff of blue smoke from the exhaust this only happens in 2nd gear in 1st,3rd,4th and 5th gear the engine revs freely all the way without any smoke,the car is not overboosting based on the custom ecu map, although the engine is modded to a reasonable level,i have checked and replaced all vacuum pipes.Out of say 10 standing starts aprox 3 or 4 of these result in sudden power loss at 5,100 aprox rpm in 2nd gear.(gearbox is manual)

The top half of the engine has been rebuilt ported,polished,gas flowed with new springs,seals and valves etc,the manifold is also ported and gas flowed,3" downpipe ,cat removed,colder running racing spark plugs,magnecor wires,itg panel filter,maf flow sensor screen removed,Rica custom map.

The Rica custom map ecu has been changed to a slightly less aggresive map again customised to the car, this has made no differance to the problem.I have done Compression tests on each cylinder showing cylinder 1-165psi 2-167psi 3-175psi 4-165psi 5-165
this was done on a cold engine which is healthy as far as i am aware.

Any help or suggestions appreciated ,dont know where to look next


A very frustrated Jason.

[tonyflynn1]

Hi Jason, Where are abouts are you located? If you can make the rolling road day at Uxbridge tomorrow you may get your answer.

Doubtful, since the rolling road dyno run is done in 4th gear. The best thing is a diagnostic dyno session, not a power run. A diagnostic dyno session can hold a car at a fixed rpm for as long as required, at full load, ie a static test, as well as a dynamic run to simulate acceleration. This is the best way to investigate the problem. You also need to hook up a decent AFR meter with a wide band lambda sensor, as well as a load of other sensors for boost, and temp etc. This kind of stuff is very rarely done during a rolling road shoot out.

Adam.

Thanks Tony but i am based in Dublin ,Ireland only for this i would have been one of the first to put my name down for the rolling road test to see how the car was running and meet some of the guys from the site.

Thanks for the suggestion though.

Jason

Hi Adam ,any ideas on where i can get this done or who can do it,the car is driving me mad,met a 02 carrera whilist driving on back roads both of us where hammering it he could not pull away from me at all,came to set of traffic lights both of us stopped ,lights turned green 1st gear nothing in it , 2nd gear nothing in it bang power loss cut in porche pulls ahead by 2 car lenghts , 3 rd gear boosting and holding 1.3/4 nothing between both cars apart from when i lost #### loads of power,was going to buy some petrol and a lighter not to refill the petrol tank if you know what i mean,do you think it could be an injector sticking closed on full tilt?

Thanks for your help

Jason

Hi Jason,

I'm not sure - it's a weird one. The problem is that it's intermittent, which makes it 10 times harder to diagnose. And for it to happen in 2nd gear only is REALLY weird!!!

Does it happen only on full throttle, or does it happen on part throttle too? Is it only 5100 rpm? Let me check with our guys to see if they have any ideas. I will email you Monday.

Adam.

Jason,

I was looking at the performance of the Carrera, and all the models seems to be around 5 secs 0-60, with over 170 mph top speed. If your car can keep up with one of those, it must be totally nuts to drive!!! We will resolve your 2nd gear issue, because I have a feeling that when it's sorted, you will have a real porshce beater, both from the lights and mid-range.

Parkers recommend a list of alternatives to the Carrera such as Ferrari etc, but it doesn't list an old T5 in there. Maybe they should ;)

Adam.

[Ben O Brien]

Hi jason
very tricky problem,in relation to the rolling roads i dont know if youre aware of this but there is a centre somewhere in the midlands i know they advertise in the buyandsell,will also take my 242 to get it tested when im finished modifying it,By the way im based in Limerick,
Best Regards
Ben
82 242 2.3 DL(Modification in progress)
82 244 2.3 GL
89 245 2.0 GL
91 245 2.0 SE
96 850 2.0 S

[Simon Linton]

I'm sure yoyu've done a search for tuners in Irealand, if not try that - the Irish must have other serious enthusiast apart from you!

BTW, I was mentioning your approach to tuning with much approval to others at the rolling road day - the engineering approach is often ignored because of its expense and time off the road, but there is no proper substitute for mechnical upgrading, despite what the chippers would have us believe.

Holistic tuning means a faster but just as reliable car (a little ironic in your case, but I'm sure there's a solution).

Best wishes and good luck - if I find anything I'll let you know ASAP.

The thing is that Jason's car doesn't need tuning, it just needs diagnostics. He has done a lot of good mechanical engineering work on his car, and had an ECU upgrade to make the most of this. He hasn't really spared any expense in his quest for power!

I do agree in that good mechanical engineering work makes for a better foundation for tuning, but as you say, it requires huge expense and effort for any worthwhile results.

Adam.