What's new

boost spike and misfire on full aceleration

V

vti_coupw

Guest
hows it goin peeps, last night i was driving home and i gave it full acceleration, the car would go to 4000 rpm and the boost would spike to over 1bar, if i accelerate slowly it will rev over 4000rpm but once i give i the full shoe again it will hold back and start misfiring and popping,
the car is a 99 s15, mods are
greddy FMIC
denso grade 7 plugs
blitz air filter
aftermarket downpipe and full cat-back,
the car has been fine just out of the blue last night this started happening
cheers
dave
 
Joined
27 April 2006
Messages
1,145
Reaction score
0
Points
0
Location
Ireland
What engine management are you running?

At first guess i would think its hitting fuel cut due to the cold weather. Double check all the vaccume tubes and intercooler piping, especially the cold pipe by the battery for holes or leaks.
 

LuPix_S15

Banned Toyota Lover
Joined
14 April 2007
Messages
3,891
Reaction score
1
Points
0
Location
Shropshire, UK
Website
www.lupix.co.uk
Country
^^ +1

Any dodgy boost management and spikes or uncontrolled boosting would make me check all FMIC piping and also the vacuum tubes that run to and from the boost solenoid...
 
S

S15 SILVIA

Guest
Hi all.
While were on the subject of boost spike and creep.
What are the wastegates like on the silvias?
I know they're internal not external,
just on my starlet turbo I had a couple of years back, they use to suffer from boost creep very easily (small wastegate) with the smallest of mods like a de-cat etc.
It was a common thing to have to get the wastegate ported to help cure this.
Just wondering if there were any issues like this with s15's?
Cheers Mike
 

LuPix_S15

Banned Toyota Lover
Joined
14 April 2007
Messages
3,891
Reaction score
1
Points
0
Location
Shropshire, UK
Website
www.lupix.co.uk
Country
I'm not an expert but from what other owners have commented it seems the S15 stock tubby is ok until you start tuning her up and once you're at the stock setup limitations of around 330 bhp then boosting towards 1.2 bar will certainly see the boost tailing off which is why and upgraded tubby plus aftermarket actuator arm should help rectify this problem AFAIK (!!)
 
Top