Car jumping in boost...

[V-Turbo]

Hi, I just bought a glanza turbo. When in boost, at around 3K rpm the car jumps and cuts acceleration, or cuts the fuel? The seller had informed me that theres a HKS actuator on the turbo and it needs to be swapped for a standard one or turned down?
Im an apprentice mechanic, but ive never encountered a problem like this before. Could be a common problem?

Any help is greatly appreciated.

 

[Weyro]

Do you have a boost guage? If its cutting out at 0.85bar then its something called Fuel Cut.

 

[V-Turbo]

No boost gauge. Must get one asap... He told me its set at 0.75 and to either swap it for a standard actuator, turn this one down, or put in an FCD.

 

[Weyro]

Yea a boost gauge is pretty vital when manually upping boost. It could be that its set for 0.75 but creeping up and hitting fuel cut.

Yea, winding out the actuator will reduce the boost level and so avoid fuel cut.
A fuel cut defender (FCD) will fool the ecu into thinking that it hasnt reached 0.85 bar. This will allow you to run higher boost, but you will need an adjustable Fuel pressure regulator to increase the fueling to make it safe.

 

[V-Turbo]

Yea, I did a bit of researching into fitting one and its not as straight forward as he said. I think my safest option for now is to get a boost gauge and turn the boost down. I dont want to go messing with it just yet, just want it running right for now.
Someone was at it before anyways... typical bolts missing and the likes (Only two bolts holding on the intercooler, reckon it had an FMIC at some stage)... and alot of vacuum hoses were connected up wrong or not connected up at all. That stuff drives me nuts!!

 

[Weyro]

Yea thats the annoying thing about having a car that someone else modified lol.

Try winding the actuator arm out 1/2 turn, then hook it back on, and go for a drive. Repeat till you no longer hit fuel cut.

 

[AdamB]

Just wind the boost down a fair amount, fuel cut isn't good for the engine so you don't want to keep hitting it. Get a boost gauge in there asap!

 

[96v]

How can the guy you got it off say its at .7 if there is no boost gauge? looks to be boosting a bit more than that as said and in turn your hitting fuel cut get a boost gauge in there, wind the actuator out a bit and problem solved

 

[V-Turbo]

Thanks alot for the help lads, appreciate it. Gonna go out now in a few mins and adjust the arm out a bit.... I dont know how he knew that its set at .75 as theres no sign of a boost gauge ever being in the car. Seems to me that hes just been playing around with it...

 

[V-Turbo]

Problem solved. Had to adjust the arm out 4 full turns. It was boosting at 1800rpm like... and was drinking the juice!! Seems ok now, boosting at just under 4K rpm. Will get a boost gauge asap.