my modlist:
GTII 7460R
Cosworth M2s
Injen UICP, LICP, intake +Amsoil cone
AMS 3.5" FMIC
Ebay o2, megan downpipe
RRE catback
RC 1000cc's
HKS BOV
Grimspeed 3port
Omni 4bar
ARP headstuds
ECUflash tuned

EDIT: the car has gotten to the point where its very laggy and doesnt spool till 5k rpm and seeing about 20psi.

so far:
- fixed all boost leaks
- fixed exhaust leak
- WG actuator is fine (have swapped with the stock one)
- Grimmspeed 3 port is fine (swapped with a friends)
- AFRs are fine
- clutch is good
- plugs are in good shape (no cracks)
- BOV is good
- no smoke coming out of the exhaust (turbine spins freely, very little shaft play)

any help is welcome

 

First step would be to use a seat-of-the-pants approach and ask yourself if it feels like electrical, mixture, air or boost flow issue? Judging by the extremely intermittent nature my first check would be electrical. It's easy enough to pull the plugs and see if one has a tiny crack or burn... then go on from there if it checks out. If nothing jumps out you may have to wait for it to get worse.

 

You will get hesitation like that if running really lean. Might help to see what your AFRs are.

I'd also check the fuel pressure, fuel filter, and fuel pump. Usually a clogged filter will cause something like that but it could be any part of the fuel system. If your AFRs check out the issue is probably elsewhere though.

Might not hurt to check the injectors if everything else looks okay.

 

thanks for the answers guys

the car's performance has declined dramatically after the last track day. it now has a hard time boosting. spools really slow, but i can hit 20psi given enough time. it doesn't missfire or anything. so far i've:

- fixed all boost leaks
- fixed exhaust leak
- WG should be good - flapper not stuck
- AFRs are fine
- clutch is good
- plugs have about 3,000 miles on them (will pull to check them out)
- BOV is good
- no smoke coming out of the exhaust

the HKS GTII 7460 comes with its own WG actuator, i can't see it backing itself off and coming loose? i'll check the preload tmr

any more ideas?

 

well check for any leaks before the turbo, check your intake pipe is connected properly and secured. All clamps on it are on tight,as well as where the bov recircs back to on the intake pipe, make sure those clamps are tight as well.

 

Compression check.

Possibly the turbo is bad?

Are you able to datalog the car? Do the logs look okay?

 

Coils

 

the intake pipe is properly secure and there is absolutely no boost leak. i ran compressed air from the 3port end through the line to the wastegate and it opens and closes no problem. the slack on the actuator seems fine too.

compression is 130-130-130-130. the plugs are all in good shape and have no cracks at all.

going to log the car and see. then going to pull off the o2 housing to check the hotside and wastegate flapper, hope there is no crack

 

+1

 

so i swapped the wastegate actuator and grimmspeed 3 port today, stll feels like i'm driving a 42R car

anybody?

 

can you do a datalog of your car and post it?

 

Do you want "slack" or preload? By the way they are running this setup on rally cars and the actuator does back itself off. Let us know what you have found please.