Need help.. car hesitating

[weegee411]

ok I've looked all over the threads to find a problem that matched mine but couldnt find one so yes I did all my mods at once and the car is running good kinda. need to bleed brakes again but anyways my problem is my car pulls hard up to full boost and at full boost my car starts to kinda hesitate. the current set up is t28 on big fmic hard piping and ssqv. car is set at 15 for now because Im breaking her in and making sure the job is done right.
help..
-done boost leak
-re-tightened all couplers
-I believe the BOV might be missing a piece but Im not for sure. all my other ones have a pin that goes to the TB but this one doesnt but has a screw???

and oh yeah my speedo isnt working now either.

 

[Alex Bland]

is there boost lag? after it boosts up does the guage go up and down like it cant hold it

 

[weegee411]

yeah but not much jumps down and up maybe like 2 psi, but I thought that was normal.

 

[Kaotic_red]

^ agreed. also...do you have any type of A/F monitoring tool. Also I would check you MAF sensor. is this stock or are you running without the stock setup?

 

[weegee411]

yeah I have an aftermarket gauge for it. and yes its stock and I have the MAF ziptied up to it because it has a habit of wiggling loose but I will redo over again.

 

[Kaotic_red]

is it wiggling from where it mounts to the turbo? If thats the case your car will ultimately running like crap. (with a stock intake setup that is)

 

[Kaotic_red]

remove the zip ties and replace with actually hose clamps.

 

[habitatguy187]

Always start with a boost leak test, then plugs, then wires for something like this. It's most likely your plugs, what kind do you have? What are they gapped at? Who tuned your aem and how long ago was it done? Was it hesitating after it was tuned? Was there any specific thing that happened before these symptoms arose?

Always give as much info as possible to threads like this, sometimes it's hard to narrow them down to the problem.

 

[Kaotic_red]

^good catch....Not my first thought but still a good idea...

 

[weegee411]

no no no the piping isn't ziptied. the connection to the maf sensor is where the socket plugs into. I have the connections ziptied together because the clip on the socket plug would wiggle loose.
-plugs and wires were just replaced with NGK.
-The AEM is not currently set up in the car right now. I removed it when doing the rest because my tuning person moved and there was no way to get my car to somewhere close to get it tuned.
-It has hesistated before but the zip tying the maf sensor and the socket together fixed the problem before.
-There has been no symptoms or anything like a big noise that happened before this it was the second start up and drive.

 

[weegee411]

and the plugs are gapped at .28

 

[awdmonster1904]

BPR7 plugs and new wires should do the trick

 

[weegee411]

Wires and plugs were replaced when the car was getting the makeover.

 

[woodnbronze24]

Could be plugs. That was happening to me. The plugs looked good but after i replaced them the problem went away

 

[weegee411]

The plugs and wires were replaced with new ones when I re-did the tranny.

 

[mkvos]

Is it possible that your car's pulling timing at full boost?

But yeah, I too as well had this problem, and was using NGK wires. Replaced them with new wires and the problem went away.
Yes you said you got new wires, but you never know, you may have been the 1 person out of 1,000 that ended up with that faulty wire out of the factory :-/

 

[weegee411]

I guess I will try new wires again. and how would you check if the car was pulling timing?

 

[nlzn]

Stop don't just run out and get new wires, especially if they were pretty new to start with.

Check the boots and the wires for cracks and tears. Check the metal on the ends of the wires especially. If they look good hit them with a multimeter checking for resistance. Put the positive at one side and the negative on the other.

I don't remember the specific values, I know the shortest should measure around 5 something ohms and the longest around 10 or 11. FSM, Haynes or Chilton's should list the values or maybe searching here.

No use spending money on something without testing them first.

 

[habitatguy187]

So if the aem isn't set up then what are you using to get around fuel cut? You'll hit it alot sooner on a t-28 than the stock t-25.

Also change your plug gap to .026 and see if that fixes it, if so then it's just regular ol' spark blowout.

 

[gsttuner22]

ok I've looked all over the threads to find a problem that matched mine but couldnt find one so yes I did all my mods at once and the car is running good kinda. need to bleed brakes again but anyways my problem is my car pulls hard up to full boost and at full boost my car starts to kinda hesitate. the current set up is t28 on big fmic hard piping and ssqv. car is set at 15 for now because Im breaking her in and

and oh yeah my speedo isnt working now either.

You mean when your driving and you hit full boost, the car sorta 2 step's from time to time?

 

[highlandgst]

well this sounds like my old problem i had awhile ago .. common too it seems . if the car isnt throwing CEL's you wont pick up on a few things fast. Change plugs wires that helped me abit but the problem lingered . I changed my valve cover gasket cause mine was old and started to leak . and then I changed my TPS and cleaned my throttle body and that solved the issue

 

[weegee411]

I changed the gap on the spark plugs, I checked resistance in the wires.
Car still hesitates but the hesitation doesn't feel like fuel cut. It doesnt jerk as hard as a fuel cut problem.
And I caught something but i dont know how I'm guna fix it just yet. My BOV isnt hooked up to my TB, but the weird part was its still letting boost out. Another problem is on SSQV theres not a place on mine to connect a hose to. theres a hole on top then a screw lower down.

 

[JMiller]

Your BOV should have a nipple on it that connects to the throttle body.
like this

You must be logged in to view this image or video.

 

[weegee411]

yeah I dont have the nipple =[ would that cause the hesitation?
I took her for another test drive today and now in first gear full boost is 10 psi like I set but in second and on the boost goes to 15psi.

 

[mkvos]

yeah I dont have the nipple =[ would that cause the hesitation?
I took her for another test drive today and now in first gear full boost is 10 psi like I set but in second and on the boost goes to 15psi.

If your BOV doesn't have that nipple, it will definitely affect the car. That nipple is supposed to be hooked up to vacuum to keep the BOV closed under boost.
That could be causing your problem. You may be able to make a nipple for it with some 3/16 steel brake line if it's fixable.

EDIT: Actually that vacuum will OPEN the BOV's diaphragm when pressure is relieve from boost.