Weird boost problem ??

BNA_ELLIS · 09-20-03, 01:40 PM

I have a strange boost problem i'm trying to solve. Car is 93 type r 47k with compression tested and good.
just had plugs changed, mods on car is a veilside exhaust catback and apexi induction and twin blowoff valves. The car boosts fine up to 4,200 rpm .7bar
the at transition for second turbo it's like a kind of misfire a pause then second turbo kicks in and boost is fine again. The only issue seen seems to be at transition from primary to secondary turbos. It does not always do this but say 8times out of ten and more noticeable when hot I suspect this is a sticky solenoid ??
The two most visible solenoid at the left of uim the right one has a dot on it is this round the correct way ??
every now and then the car feels a bit sluggish if I back off the throttle and reapply boost is back to normal again, also this is intermittant and only when hot. I guess the later problem is a hose collapsing under then heat when engine is hot but the first I think could be a solenoid issue. Any advsie will be welcome.

rgds

Rx-7$4$me · 09-21-03, 03:48 AM

What are your mods? hopefully your not spiking and hitting fuel cut during the transition. If you get past 4.5 k rpms and then pop back down to say three if you upshifted or somthing, your car is still in non-sequential ( your secondary turbo is still active for a few seconds) so thats why if your off on and you might be slow to building boost.

BNA_ELLIS · 09-21-03, 07:55 AM

Hi mods,

are veilside catback, apexi induction kit, twin blowoff valve and some aftermarket ht leads. This only happens when hot when cold there is no osund of misfire during transition. Even when hot after the strange transition boost is fine up to redline which is why I think it's a solenoid. Not a boost spike, boost is at a perfect. I have check vacumm lines at rats nest all are ok. Map sensor pipe is ok.

rgds

Rx-7$4$me · 09-21-03, 02:43 PM

do you have a boost gauge? how do you know your not spiking?

BNA_ELLIS · 09-21-03, 02:55 PM

I have a hks boost gauge installed. Also not only have i experienced this at wot, but I have gently accelerated too and when I get to about 4,200-4,300 rpm the same thing happens and only when warmed not never when cold which makes me think a solenoid is suffering from heat stroke which one I have no idea??

rgds