[SupraDreamer]

Ok my car has throughly pissed me off at this point, it seems like I fix one thing and something else goes wrong. Here is the current situation, I just installed the HKS hard pipes and an RMM downpipe. My car now acts really strange when it is in boost.

When I get to about 10lbs of boost, the car starts stuttering and hesitating while making a farting type noise, and it wont pull for dick. I know what everyone is gonna say, my intercooler pipes are loose, but I have checked all the connections 100 times and I can't seem to find a leak. Is there anything else that could be causing a boost leak, if that is what it is.

Please I need possible ideas for things to check.

 

[BlitzTT]

U might wanna list all the mods you have on the car... if thats the only mods on the car then its the fuel cut off... that is if you dont have a BCC yet.... that would be one indication on it.. or if you do you dont have your BCC adjusted correctly... but I hope you DO have a BCC already.... list your mods so we know.... easier to tell whats wrong.... good luck....

 

[SupraDreamer]

Here are my mods:

RMM down pipe
exhaust
Egr mod (blocked hoses)
manual boost controller
HKS hard pipes


I don't have a BCC yet, but the car ran fine right up to the point when I installed the hard pipes. I was running 15PSI before the hard pipes and the car was fast as hell, but like a day after putting the hard pipes in the car starting pulling like crap. I even tried taking the boost controller out to dial down the boost, but even at about 10PSI the car hesitates and sputters.

Any ideas?
How can I tell if it is fuel or boost cut? The car seems to be running way rich though, as it really stinks.

 

[weedwhacker]

umm

your hitting fuel cut...the downpipe upps the boost itself...


get a greddy bcc

 

[aznsupra]

the fuel cut will feel like your car will just stop goin. you'll accelerate really fast, then all of a sudden u will be sort of thrown forward b/c the car wont go faster. in your case, i doubt u were ever makin 15 # of boost since it will cut off over 14 after a few secs, but what i dont get is that u were running a dp/exhaust etc and im pretty sure running in excess of 14#'s and u dont seem to have had any fuel cut probs b4 the installation. the hardpipes u put in will help build boost better and more efficiently, since the regular piping expands makin it less effiecient. but i have to agree with the others, and its probably that you NEED a bcc, try puttin one of those in and let us kno...good luck
kevin

 

[SupraDreamer]

Alright I was planning on buying the BCC anyway, but I hope this is all that it is. It just seems like it is kicking in at about 10PSI, and before the pipes it pulled fine to around 14 or 15 PSI. I will let you know if it solves the problem. Thanks for the input though.

 

[dzeiler]

I hate to be the dissenter but there is no mistaking fuel cut and this isn't. with fuel cut you are accelerating and then Wham no farting noise etc no stutter. this sounds more like an actuator of the second turbo( lower boost etc.) I suggest the temp TTC to see if that makes a difference. especialy before going to the bcc.

 

[SupraDreamer]

Alright I will try this first, as I was planning on going ttc. But if it is the actuator, then this problem should go away correct?

 

[Emanuel]

This is fuel cut! Had the same problem, doesn't matter if mt or at...
Greedy BBC will fix the problem, because of the turbos are spooling much quicker with RMM than without.
You can test it when you accelerate with 3/4 of full gas...

Cheers, Emanuel

 

[SupraDreamer]

Guess what, I don't think it is fuel cut. I tried to doing the free fuel cut mod and the car still does this problem. Also it is not occuring at full throttle, I still have the problem at around 2/3 - 3/4 of pedal travel. It really seems as though it may be a leak somewhere, but where?

All the intercooler pipes seem tight. Is there a site where they show how to pressure test the piping.

Can the stock BOV be releasing the pressure? How can I test this.

I am gonna try the TTC mod to see if it is the actuator, but I had a friend try to pay attention to where the problem starts, and it seems to occur after the 2nd turbo comes online and I start making about 10-11psi with both turbos (right around 4600 rpm's).

I greatly appreciate all the help I have been getting, now I just wish my sick dawg would help me out, and tell me where it hurts!!

 

[joshbumbaugh]

An idea...

Have u checked all your spark plug wires? How old are they? When installing the DP, u didn't by chance get any penetrating oil on the wires did you? Bad spark plug wires usually show up under boost, and you seem sure that you don't have any loose I.C. pipes, so u might want to check all the connections on your spark plug wires. Also, flex them and check for fraying. Just an idea, I'm sure at this point you're grateful for anything, I know I hate it when my babies don't run right. (Which seems to be like every freaking day)

 

[SupraDreamer]

Thanks for the input.

I changed to a new set of stock plugs like 4K miles ago and since the car is the coil-on-plug setup, it can't really be the wires.

I just pressure tested the whole intake track from the beginning of the intercooler piping up to the throttle body and I cant find a leak anywhere. This is becoming very frustrating, and I can't seem to figure it out, any ideas are welcome!!!

 

[Nexxus]

You said it occurs when the second turbo comes online. Maybe you should check the IACV located above it. It is towards the back of the motor on the left. See if one of those small hoses has popped off the actuator.

josh

 

[joshbumbaugh]

Well, since I've already proved that I'm a moron when it comes to the Supra's Ignition set up, maybe I could back that up even more.:hammer:

What are your plugs gapped at? Should u be running stock plugs at your level? I know that one of the first things I did was to install a set of plugs that were one heat range colder and narrow the gap slightly to prevent "blowing out" the spark. Yeah I know the term sounds stupid, and I didn't believe it at first, but it kept appearing in tech articles everywhere.

Sorry, I keep getting this semi-mundane idea that I can help.:dunce:


Did I mention that I personally can't stand it when my POS cars don't run? Anyone know of anything dependable?

 

[SupraDreamer]

I tried running the car in TTC mode and the problem is still existent. I am running out of things to try.

How do I go about testing the actuators individually to see if they are working?

I am now beginning to wonder whether it is my ignition system? But it isn't a problem that is coming and going, it always happens at about 3/4 throttle or more and when I am pushing just a bit more than 10psi. What would cause the ignition timing to be retarded, besides the traction control (pulled the fuse) and boost/fuel cut (did the FFC mod, and 12v fuel pump mod).

Should I be running one heat range colder with my plugs?
I gapped my stock plugs at .33 or .34.

 

[SupraDreamer]

Finally fixed!!!!!!

I finally figured out what was wrong with the car, and now I feel like a complete idiot. I had my plugs gapped way to big. I gapped them down to ~.030 and the car runs very well and even idles nicely.

Thanks for all the help people. Now I just have to fix the damn taillight computer so that I have some brake lights .