Car surges after boost ? Pls help

[Iceey]

Hey guys
I have much to learn about turbos and what not and I have been searching around the net until my fingers hurt .. I know for sure you guys would know the answer ..

Well I have a 1993 gsr 4g93 and I've notice she's been surging under low boost (<5psi) when I let go of the throttle .. Everytime I feel it surging the little boost light flashes .. It's like it jerks me forward ..

Please help

 

[trq-str]

How about when you are above 5psi or does the jerk prevent you from going over?

 

[Iceey]

Above 5psi when I let off the accelerator is fine .. Bov d

 

[Iceey]

Above 5psi when I let off the accelerator is fine .. Bov does what it does

 

[trq-str]

Ohhh ok.... I thought you had a real problem.

Well you definitely should not feel a jerk when your turbo is chattering. Since it is occurring off load, it will not cause a problem as you are not experiencing real turbo surge.

I can not understand why you are feeling this jerk, perhaps it's placebo? or.... you do in fact have a problem, but it is not related to your turbo?

It's like it jerks me forward

It's like is jerks you forward or it actually does? This is important.

 

[BMGTZ]

vent to atmo BOV?

 

[Iceey]

Yeah the jerk feels like power cuts out for a split second

 

[Iceey]

vent to atmo BOV?

Yeah the bov is currently on atmo

 

[Cranked]

Yeah the bov is currently on atmo

That's what I'd say is your problem, if it has a factory ecu, the tune accounts for that air that is being recirculated back into the intake of the turbo.
Switch back to recirc and see if the problem is still apparent.

 

[Benzo4gT]

↑Exactly

Car making lots of pshh noise and running worse :blink:. Been getting tuning tips from guys with riced Hondas by any chance? :lol: Sorry, couldn't help myself

 

[BMGTZ]

as others have said return to the recirc BOV....or soften spring on atmo and see if it helps.{probably not}

 

[trq-str]

Does it ever stall when you come to a complete stop?

 

[Iceey]

I'll plumb it back to recirc and give it a shot

 

[Iceey]

Does it ever stall when you come to a complete stop?

Sometimes the revs do go down .. But never stalled

 

[Iceey]

I've been doing some searching and it says the wastegate actuator should be plumbed before the throttle plate ? Is this true ?

I had a look at where my is plumbed and it's connected to a T piece .. One leading to the BoV and the other after the throttle plate .. Is this right ?

 

[4piknup]

Before the throttle is true.
Yours is wrong.

 

[GeoKez]

If your off throttle, your not making boost. What's the theory behind the prior to throttle plate rule? If your running an aftermarket boost solenoid does this still matter?

 

[BMGTZ]

both are ok.....

when it is in the manifold you get a true boost at the valve reading. if the boost is too high the actuator opens so all good. when you get off the throttle there is no boost in the manifold and the actuator shuts...simple

when it is in the cooler pipes it does the same with one slight down side called a blow off valve to contend with....as there is a slight lag between the valve venting and the throttle closing. ...that can cause a little hiccup as you come off the throttle.

my preference right or wrong is detect boost from the manifold

 

[khubner1]

Here's how it is factory

Waste gate (this is different to bov) -> t piece -> one end to cooler piping pre throttle (on the j pipe for gsr somewhere on the cold side for evo) other end to boost control solenoid (factory two port)

Bov -> vacuum source after throttle

Boost gauge t into bov source.

 

[EVOCPE]

Dont T the boost guage on same port. Use the fuel pressure vacuum