3sgte surging boost

[punkture]

hey, hte 3sgte on my alltrac st185 everynow and then surges boost, will reach 10 then drop to 9 etc then back to ten, and you can really feel the power loss, doesnt do it constantly only intermidantly, havent changed the fuel filter and economy is 30km to 1/4 left in tank from full, inc 2 hills drives (up and back) and freeway. thx

[RobST162]

you used up 75% of your tank to go 30ks mate? something's wrong there dude

are you using a boost controller?

[punkture]

lol sorry *300km no boost controller, my understanding was thier was one but they took it off and replumbed as normal, running 11~12psi.

[RobST162]

are you using tvsv (the other line into the wastegate actuator)?

[punkture]

yeah, dble checked that its all plumbed up, there is a slight delay though upon when my boost gauge reads 0psi-10psi and my on dash one..is the fuel economy okay/avergage? all plugs, leads dizzy cap etc replaced

[punkture]

okay, had a chance to really suss it, when it feels like its surging it blows black smoke (too rich) could this be the afm?

[MWP]

You can't judge fuel use from the gauge.
They are normally very innacurate.
Make records of kms traveled and how much fuel you put in it to properly work it out.

Blowing black smoke is normal, they do normally run very rich on boost.

You getting any more ecu error codes?

[punkture]

nah no ecu code..yeah but im talking like james bond smog screen black hahah..only when it does its hissy fit though normally its fine, my step dad reckons maybe bung AFM

[MWP]

Temp sensors could cause that too.

[punkture]

hmmm wouldn't they throw a code though?? in the morning when shes dead cold sometimes it takes a lil longer to start to..if thats anyhelp, im gonna go scrounge a multimeter and test the AFM and the water temp sensor

[punkture]

okay the water temp sensor, on right of cold start switch read 3.08kohm. that's apparently meant to be at 20*C and i did it even before the engine was run..so 0*c~5*?...any thoughts, testing the cold start switch now, read 0.001ohm.. is meant to read 30-50 below 10*C and 70-90 above 25..this was STA-STJ on the feed switch. buggarded?

[punkture]

bumpedy bump bump..re tested the cold start 80ohm at roughly ~10*C.. the 3.08kohm for the water temp must be right, but that cold start says its meant to be 30-50ohm under 25*C, i removed the cold start plug on the water tee and started car, it threw the water temp sensor code..22 'open or short in water temp sesnor' wats with that?