Nissan 200SX Club - South Africa

Guys I need your help.
My car is breaking down in Boost. If I drive it and gradually accelerate then the car goes better but also break down eventually. But If I accelerate putting immediate load then as soon as I hit boost at 0.5 bar then the car breaks down badly.

Any ideas? Anyone had similar problem before?
I must admit the forum is growing and becoming useful.

Explain "breakdown" does the boost drop or the car breakdown, give a better dicription of what happens then we may know what to say.

The car breaks down. so badly that I can't accelerate any higher than that point. Strange thing is that when in neutral and you ref the car it refs clean.

i had a similar problem!!! yea me!! ok here it is this was my problem im not saying yours is the same but its worth giving a shot!! mine was the coil packs that started building up some sort of electolite coused by not connecting properly to the sparkplug!! cos the previous owner took the spring load out of the coilpack so i made some springs from thick copper whire!! how you ask?? just rap the copper around a screw driver thats more or less the same size as the coilpack hole!! but clean the coilpack out nicely first! and just a word of advise spray some silicone spray in there otherwise it starts to build up again!! hope this helps

Break down, means comes to a complete stop & doesn't run, or are you talking about boost spikes.

Boost spikes happen when the plugs are incorrect. Fueling, I can't think of anything else, just yet.

Break down, means comes to a complete stop & doesn't run, or are you talking about boost spikes.

Boost spikes happen when the plugs are incorrect. Fueling, I can't think of anything else, just yet.

There is still not anough detail but it sounds like you might have a petrol problem, your fuel pump may not be able to give the petrol you need, or the mapping of your ECU can not cope with the application. If I remeber correctly you said it boosts 0.5 bar, that is low for petrol to be a problem.

You might get detonation but again your boost is very low, so that too might be off the point.

You will need to give all the detailes, what car it is(hopefully an 200 sx),
what turbo and everything, details details details....otherwise I might not get the whole picture, not to say I will be able to give you advice, but I'll be able to give you better info if I have it all.

It might be coil packs aswell as previosly mentioned.

The car is standard 200sx. No changes were made besides the battery (cause it's new) and there is a dump vavle added. I will be changes the plugs tonights. I am looking for an extra st of coil packs to test with, but spares in CT is scarce.

Woohaa you mentioned Boost spikes. What exactly happens with boost spikes. Does it clear or does it continue throughout. Cause my car drives fine under boost.

As the boost rises all of a sudden you'll here a pop sound & the car gets held up. I knew these were boost spikes because i used to have a boost gauge & has the revs climbed towards 0.5bar all off a sudden it will shoot up to 1bar, & drop back suddenly.

The cause for this in my car was that it didn't like the standard spark plug. Very strange I thought as the only thing that sorted it out was to run a hot plug.
the plug I have has two electrodes & can't be gapped....but it works.

definitely not boost spike cause the boost remains at 0.5

Like i said it sounds all to fimiliar to me. check your ignition system ie. your sparkplug gaps sparkplug it self and your coilpacks but like woo haa said it sounds like plugs!! hope we helped??

Id be looking for a boost leak if i was you. Just make sure all the pipes are fastend.

Unfortunately theres so much that can go wrong. Do a check for fault codes while your at it.

It wouldnt be a boost spike IMO if you dont have a bleed valve, those are known to cause boost spikes. I had boost spikes at a stage and it never caused any of those symptoms. Perhaps a duff spark plug. But my money is on a boost leak. check little pipes coming off your boost pipes aswell.

Oh and the vacuume pipe that connects to your FPR make sure thats on, and all the other vacuume hoses that connect to the solinoid under the coil power thingy (i know theres a name for that )

I have also put in new spark plugs, the ones recommnded,(according to the NGK spark plug guide) for the sx the twin electrode.
I have moved coil packs around still getting uneven idle on only the one cylinder.
thought it was the injector as stated in my injector post last week.
BUT
Apparently I've got a boost leak aswell,this is what they say might be causing my uneven idle as the AFM might not produce the correct reading for air, not to sure every where to check i'v checked the main boost pipes from turbo to just before intercooler,cant check intercooler connection dont know how to get in there, from after intercooler to the intake plenium(I think thats the termenology ) Havn't checked all the little pipes coming off of it. will do so

Oh and the vacuume pipe that connects to your FPR make sure thats on, and all the other vacuume hoses that connect to the solinoid under the coil power thingy (i know theres a name for that Embarassed )

Would like more details on these need to check them. By FPR you mean fuel pressure regulator right? and the thingy whats that and where is that, I think you mean from where the wires come from that go to the coil packs? Right?

It could be any of those things that may couse your car to run bad or idle uneven, but breakdown I don't think so, the only whay the car would breakdown when driving hard is when it looses spark completely or petrol completely or even loose compression completely.

Thats why I say detail breakdown properly, does the car stoll or does it start jurking......?

Ero-sennin if you run the wrong sparkplugs it will run uneven, the safest plug to use is NGK bcpr6 or 7 es, 6 is a hot plug and 7 a cold plug. I must say my car has never ran 100% even on idle, it runs smooth for about 10 or so seconds then it gives a fast miss then fine again for some time then misses fast again, no one could get that away, not even after I redid the engin.