S14 SR won't boost over 5psi?

[BoBa524]

So, i've had my S14 sr for about 1.5 years now. It's a stock sr and i have always had a manual boost controller set at 12psi. This past winter, the boost dropped to 4-5psi max while it was set at 12psi. So i figured my cheapo boost controller crapped out over winter, so i tossed it. But the boost did not return to its normal stock 7psi, it stayed at 4-5psi max. Now i got a new manual boost controller and no matter how much i crank it up, the boost will only reach 5psi.

Car has no vac. leaks, all new vac lines as of yesterday. Wastegate is getting its vac/boost from the fpr.

I connected a vac/pressure pump to the wastegate actuator and it will start opening as soon as it reaches 3psi of pressure.

I think that my wastegate actuator has crapped out. Anyone with suggestions or thoughts please help me out. It's finally nice outside and i need more boost!

[Justin35ll]

I was gonna say the wastegate too

[IanS]

Your wastegate actuator is junk. Buy the HKS adjustable one, they rock.

[MATTs14]

Im having the same problem on mine. Ive got a synapse engineering external gate but you can hear it open at around 3 and ive got the gain and duty on my Gizzmo MS-IBC set above 30 lol. Safe to say its crapped out??

[BoBa524]

ok so i decided to go ahead and purchase an s15 turbo...

installed it and the car still wont boost over 5psi.

Im stuck and puzzled, even with the wastegate unhooked from boost source it still doesnt boost over 5psi...

any other ideas?

[hungryjoseph]

did you reuse the wastegate? is your gauge reading right

[dc1984]

ive always heard that having ur wastegate hooked up to a source that includes vacuum can ruin it. are u sure u dont have a boost leak somewhere? as in youve done one of those leak tests where u manuelly use a compressor and a gauge to pump it up to about 15 psi of air to see if it holds? some people will just check all ther IC couplers and clamps and assume there is no leak. ur BOV might be leaking. aslo youve mentioned youve had it in for a good year and a half, ur intercooler might have finally givin out and just has a big leak in it. to test the intercooler or BOV individually to try and pinpoint/eliminate possibilities of the problem, u can do that leakdown test with the air compresser on just the intercooler itself or the one piece of pipe that has ur BOV on it. just block off one end and hook the air/gauge up to the other end.

here is a link to the boost leak test.

http://www.nicoclub.com/articles.php?id=158784

verry handy piece of equipment

i know it was just asked but did u still reuse ur old wastegate actuator with the new s15 turbo? the hks wastegate actuator only costs like a hundred bucks and can go up to like 12psi without the use of a boost controller. perfect for quality and simplicity.

as for matts14, disconect ur MBC. just have ur boost source going straight to ur wastegate actuator wihtnothing in between and see if the problem still occurs. if not, then it is ur MBC, if so, the problem lies elswhere.

this sort of thing is pretty much a matter of "process of elimination" to figure out what the problem is.

let us know what happens.
Modified by dc1984 at 7:26 AM 6/18/2009

[BoBa524]

I will go ahead and do a leak test next week, but if i had such a large boost leak wouldnt my car jost bog down and have zero power under acceleration?

The wastegate actuator is the new one that came with the turbo.

[the converted]

Could be a boost leak. If you need a hand I'll be around all next week, plus it would be nice to see this other than driving by you on Arsenal St.

[BoBa524]

Could be a boost leak. If you need a hand I'll be around all next week, plus it would be nice to see this other than driving by you on Arsenal St.

aren't you the one that bought the 5spd conversion from me? i gotta do all my work at my shop since i have to tools at home.

[the converted]

That was Sean (Magikdragon), I was going to try and tear the windshield out :-) But if you want a hand let me know. I'm in the process of looking for a job and need things to keep me busy.

[Justin35ll]

Damn sucks your still having the problem.. The other day I had my MBC cranked too high by accident and I think I overboosted it a few times on the highway. I took a ramp to get onto another highway and was in 3rd and punched it and it backfired and was hitting 4 - 5 psi. Cruising in 5th I'de floor it and couldn't get it to go past 2psi.

I drove for another 10 mins thought I had a boost leak checked for leaks and nothin. Turned the car off let it sit for 20 mins came back and it was fine.

It was pretty stange hopefully it's nothing to do with the ecu. I don't know if these ecu's come with a limp mode like the newer obd2 cars come with. I know when my 2001 jetta f***s up it won't boost over 5psi

[grmreapr]

also cant hurt to check your maf this is what happened to me when mine was on its way out.

[GoTRicEo0]

Gonna sound stupid.... boost gauge broken ? If not. Major boost leak

[cody180sx]

i was going to mention the same thing i was messing around under the hood of my motor one day and i went to move the plastic line that they come with and i broke it they git brittle over time and i couldn't figure it out for a week went to the local parts store and bought another reads fine now and i knew i had mine set at 10psi and it wouldn't get over 5-6psi until i replaced it

[BoBa524]

so i made sure that my digital boost gauge was reading right and it is.

Smoke tested the entire intake system with an EVAP smoke machine and no leaks anywhere. I work on VWs and i know what leaking boost sounds like i dont have that.

The BOV is not stuck open and realeses pressure as soon as it senses the vac(HKS2.)

Someone mentioned that a bad maf could be a problem so i'm going to proceed with my upgrades and install my z32 maf, 550ccs and a tuned ECM maybe that will take care of the problem. Otherwise im cim stunned.

any other ideas would be greatly appreciated.

To be exact, car doesnt boost over 3psi.

[the converted]

Did you check the timing on the cams and cas?

[BoBa524]

Did you check the timing on the cams and cas?

no i didnt, didnt think that i really had to cuz the car runs fine. I will tho if u think i need to.

[the converted]

I've seen it before where timing does weird things, so now it's always one of the first things I look at. Also with a turbo car, a lot of it not running well you can try to rationalize to the turbo not putting out as much air as it should, and not notice that it isn't running quite right other than that.

[240_SeX]

Any possibilty of a pre-turbo exhaust leak? such as a cracked mani, bad mani to turbo gasket ect...

You would probably be able to hear it, just throwing it out there as something to look into

[BoBa524]

Replaced the turbo with an s15 one, problem was still there. Replaced all exhaust gaskets in the process. Smoke tested entire intake with no leaks.

[grmreapr]

im still gonna go for a maf problem mine wouldn't boost over 4 psi checked everything switched mafs and it cleared up and not a problem since.

[dbrass240]

same actuator on new turbo?

is the car bucking or anything - a bad maf will make the car hesitate - i thought he said it was just only able to push 5 pounds...

[BoBa524]

same actuator on new turbo?

is the car bucking or anything - a bad maf will make the car hesitate - i thought he said it was just only able to push 5 pounds...

dude that question was asked 2 times before.

anyways i fixed her. my high-flow catco cat was clogged. Not so freakin high-flow. I was wondering why my exhaust sounded so quiet...so i gutted the cat and back to stock boost at 7psi on the s15 turbo:)

Thanks for the help guys.

[SR20_S14]

cat delete.....makes some power...save the hassle