Engine stuttering but sometimes reaches boost

[McMsk]

Hi Guys,

I need some help, because I don't know what it happening. I have a Greddy FMIC, an HKS Sportturbo, Apeci SAFC II and a Profec E-01 boost controller.

Problem: When i drive the car stutters uder boost, but it builds up boost till about .78 bar. But like on my way home at night, it builds up boost till 1.3 bar, the way I would want it. But i don't know why it is stuttering, under boost by 1.15 and 1.3 bar it have an air fuel ration of about 12.5 but by less boost the air fuel ration is ok. I do not know why it sutters, might I need to install my walbro. The Profec shows me, that the solenoid goes on and off realy fast after each other, but i don't know why. I once had a slight boost leak and then it was similar. but now i don't know what it is, because sometimes it builds up the boost but sutters till it has the boost.

My HKS Sportturbo has a adjustable wastegate, it is a goof idea maybe to try it without the boost controller and use the adjustable wastegate?

What does the set, gain and start value influence on the boost controller?

By the way I might have blown metal head gasket as sometimes the temperatur goes all over the place, and then I need to fill up the water.

Thanks a lot guys, I realy appreciate your help aspecially as my car is realy anoying me at the moment.

Mark

 

[xarewhyayen]

sounds to me like a boost leak.. id look up how to make one of those home made boost leak testers. Then work from there. Problems like that usually end up being boost leaks so id advice going the cheapest route first and checking for boost leaks. As far as your temp, and filling "water" which i hope you're not using just water, as its bad in the sense of rust, corrosion and coolant lubricates your cooling system. Check your oil for the milkshake effect(coolant in oil). If you have this, stop driving the vehicle immediately Good luck

 

[jdub]

Hi Guys,
My HKS Sportturbo has a adjustable wastegate, it is a goof idea maybe to try it without the boost controller and use the adjustable wastegate?

I would try this...disconnect the boost control solenoid completely and route the line directly from the compressor output to the wastegate. This will set you at default boost set by the wastegate actuator. If the problem goes away, it's the Profec, the wiring (a short), or the solenoid. If not, I would suspect the wastegate actuator is bad...the TRSM has a procedure to test a stock wastegate actuator, I'm sure you could do the test on yours.

As far as the Profec goes, no experience with one...maybe someone else will chime in on the rest of your question.

 

[McMsk]

well if I rev the car without boost ( little gas only) then it is fine. I also think it might still be a boost leak somewhere. should i try to detache the boost controller and go with the adjustable wastegate? I cannot tell from where else I could be losing boost, because before yesterday checked on that and i cannot tell i am loosing any anymore. Bevore that I was able to tell because at someparts the IC where a bit oily then I knew, where oil comes out, air comes out. I can maybe go and recheck if the pipes are oily again. the only place. i walso reatached the IC piping to the turbo as It was a bit oily there. Where do I find the instructions to build a leak tester?

 

[McMsk]

I forgot to mention, that my IC piping came with broken BOV and as I already had an HKS BOV. I took that BOV off and closed It with a pieve of metal and some sealant. After that the car worked better, but once I raised the boost even a bit higher, the porblem came back, and I saw the metal had bown of a bit. I could tell by the way the sealant looked. But now I put on new sealant and it should be better. How would you guys close the flange? I bought some so called "gluemetal" (translation from german) It is supposed to like weld metal together. Is this a good idea? Does any one have expereince with this kind of stuff?

 

[xarewhyayen]

http://www.vfaq.com/mods/ICtester.html

Shortcuts only hurt you in the long run, id have someone weld it, or get a diff pipe. Supra is a tempermental car and it knows when u do a half ass job

 

[McMsk]

Well as I thought of selling the bov i should maybe with flange so it needs to come out of the pipe anyways

 

[xarewhyayen]

p.s. Be careful because running really rich can be dangerous ( if you have cat(s) they heat up ALOT since boost leaks mean ultra rich condition, which could cause a fire) Also probably fouling all of your plugs and leaving a ton of carbon in the motor. I'd try n get this taken care of.

 

[McMsk]

Is there a way of blocking the bov somehow, like by anhancing the spring or so? Then I would put it back on for now to close the flange. It worked fine, but from about .75 bar it caused a boost leak. As far as I could tell it is greddy type s or so. The part that is broken is the adjustment screw at the top, the threads are torn out.

 

[7M-GTE]

do you have a bov on it now? or did you just close up the hole where your hks was?

 

[McMsk]

No, my car acutaly has 3 BOV

One stock not coneected, just left in the car to keep the hose closed on the accordian hose. One HKS SSQV which is connected instead of the stock one, to the stock outlet on the 3000 pipe. And one Greddy Type ? Bov on the hardpipe attached to the 3000 pipe, also not connected, but now replaced by a metal plate.

By the way, what do you set with the scew on the HKS BOV anyways?

 

[McMsk]

What kind of PVC cap is used in the FAQs? Like the lid of a spray can or what?

 

[McMsk]

Does anyone know what kind of PVC cap was used?

What might be causing my enigne to loose water. Might it help to retorque my head, since the eingine has gone a few thousand kilometers since it was reasembled.

Thanks Mark