Boost & hesitation problem

Nossske
Learner Driver
Posts: 7
Joined: Fri Jan 12, 2018 7:06 pm

Boost & hesitation problem

Postby Nossske » Sun Jan 21, 2018 6:20 pm

Okay first off I’ll start with that this is my first turbo car and first wrx, car is a 2007 wrx cs9, mods are 3”TBE,avo inlet from turbo, mishimoto Radiator and a tune.
For some reason but my wrx has been having trouble with boost and hesitation, when driving in 2,3 around 2000-3000 rpm range it’s starts to hesitate but when coming onto boost it’s fine, sometimes when it does the hesitation the boost drops to 5-7psi, when boost drops and if I go threw the rev range boost starts to creep up past 4500rpm to 8psi in 2nd, 10psi in 3rd & 10-12psi in 4th and then sometimes after a pull in 4th full boost will come back and car runs like a angel.
When the problem first started I filled up one day and used 7/11 98 fuel when I usually use shell 98 cause I got my tune on she’ll 98 and ever since then car has never been 100% . When the car drop boost it hesitates a fair bit and drives pretty crap, I have changed my spark plugs and have found a bit of red in the centre, I always fill up at shell and use 98. I changed my MAF and was really good for a few weeks but has come back again.
Could anyone help me out or point me in the right Direction please!?

mv75
WRX STi Driver
Posts: 857
Joined: Sat Dec 27, 2014 9:26 pm
Location: Brisbane Northside.

Re: Boost & hesitation problem

Postby mv75 » Sun Jan 21, 2018 9:26 pm

Red what? Coolant?

Nossske
Learner Driver
Posts: 7
Joined: Fri Jan 12, 2018 7:06 pm

Re: Boost & hesitation problem

Postby Nossske » Mon Jan 22, 2018 12:35 pm

.
Last edited by Nossske on Mon Jan 22, 2018 2:04 pm, edited 1 time in total.

Nossske
Learner Driver
Posts: 7
Joined: Fri Jan 12, 2018 7:06 pm

Re: Boost & hesitation problem

Postby Nossske » Mon Jan 22, 2018 2:04 pm

mv75 wrote:Red what? Coolant?

Red on the spark plug itself, coolant is fine.

jays22b
Learner Driver
Posts: 4
Joined: Wed May 06, 2009 6:16 am

Re: Boost & hesitation problem

Postby jays22b » Mon Jan 22, 2018 10:55 pm

7/11 fuel to my G3 is great. Caltex is the next best i would use. Wouldn't go near shell if it was last place left. After all the stories of vpower geling up dirt bike carby's.

If not stumbling anywhere else it's not a vacum leak so chase bad fuel filter. really need fuel pressure looked at. A tune should never go off. Check the wastegate lever moves easy. Maybe getting stuck.

mv75
WRX STi Driver
Posts: 857
Joined: Sat Dec 27, 2014 9:26 pm
Location: Brisbane Northside.

Re: Boost & hesitation problem

Postby mv75 » Tue Jan 23, 2018 4:07 am

Agreed. Even better fuel is from united which is my preferred as they do e85 for one. :)

Anyway, been thinking some more, could be they didn't tune out the stumble. I think there is a stumble problem in the tunes on those. I'll have to get around to finding the references again.

In the mean time, yea, do a new fuel filter. Always a good thing to replace all the filters and fluids on a newly acquired car like this. Also stock intake box? The maf shouldn't have had to have been replaced, they're pretty good ones.

I looked it up and saw what you mean about the red. More than likely the shell fuel as they use a different additive method to gain their 98 rating as opposed to everyone else. Have you reset the ecu in the mean time? Remove the battery terminal for a minute or so.

Nossske
Learner Driver
Posts: 7
Joined: Fri Jan 12, 2018 7:06 pm

Re: Boost & hesitation problem

Postby Nossske » Tue Jan 23, 2018 6:58 am

Gonna get a fuel pressure test today and go from there, I’ll also talk to he boys about a new fuel Filter. I filled up half a tank 2 days ago with Caltex and just after I drove out of the drive way the car ran like crap, boost drop to 5-7psi (but would boost to 10psi in 4th going past 4500rmp range) car was hesitating really bad.
I got my mechinaic to check my wastegate and he said it looks fine, sprayed some wd40 on the arm aswell, and yes stock air box.
And yes have got my Mechanic to rest my ecu and still the same, my car has the pin pad Alarm System thing so I can’t rest it my self.
Thank you for all help, just can’t figure this problem out!

Nossske
Learner Driver
Posts: 7
Joined: Fri Jan 12, 2018 7:06 pm

Re: Boost & hesitation problem

Postby Nossske » Tue Jan 23, 2018 8:41 pm

Update- mechanic said that fuel pressure was fine and also said the fuel filter was fine aswell, he’s taking the brants alarm out tomorrow, that may be the problem but who knows.

rileywrx
Learner Driver
Posts: 5
Joined: Sat Feb 17, 2018 6:28 pm

Re: Boost & hesitation problem

Postby rileywrx » Sun Feb 18, 2018 6:27 pm

I think I'm having a similar issue. Doesn't happen all that often though, but when it stumbles it's noticeable.

Did you pinpoint the issue?

Also, is your rex a MY08? What kw you pulling with your mods?

Return to “Engine, Driveline, Exhausts and Turbos”

Who is online

Users browsing this forum: No registered users and 2 guests