UCF_S2K

Hey everyone,

I bought this turbo S2000 about a month ago and I'm still learning everything about S2000's and turboing them.

Two weeks ago I noticed the boost gauge was sitting at -14 and it wasn't moving. When I did a pull it would backfire at a certian point. I checked everything and I found 2 burnt vacuum lines. I immediately replaced those and everything was fine after that. The gauge was reading correctly and the car was pulling as it should.

2 days ago I noticed that the gauge was sitting at -9 for a long time and wasn't moving. Then it would sit at -10 for a long time and not move, and then -8 for a long time and not move. The gauge read as if the car wasn't building pressure, but it was maintaing the same pressure through all RPM's. The car still pulled fine and the BOV would release pressure on a heavy shift, so I know there was in fact psi being built up.

So here's what I have done:

-The first thing I did was check all of the vacuum lines to make sure nothing was burnt like last time. Everything appears to be fine and I can't find anything burnt or disconnected anywhere.

-I recently got a vented hood and the boost gauge I have is pretty cheap, so I thought maybe the boost sensor got wet and shorted. I replaced the sensor with a brand new one, but it did nothing.

-I thought that maybe the boost gauge just went bad since it's bad quality, so I replaced the actual gauge; but it did nothing.

I took the car for a drive around the block and the boost gauge is sitting at -14 and isn't moving.


What should be the next thing I check? I really don't know where to go from here. Any help would be appreciated!

cuci591

Check the compression or do a leak down test. If you have checked all vac lines and they all look good then your problem is somewhere else. your car should be reading between 18-20 vac.

UCF_S2K

What is a leak down test? The compression should be fine because the car is driving normally and pulls fine. But then again, I don't know an insane amount and could be wrong

helloimsteve

+1 for Vac lines. Common problem for not building boost is vac related. If there's a leak, you're tossing out air. Check the lines to your wastegate and boost gauge etc.

UCF_S2K

I have checked the vacuum lines and they all seemed to be connected properly. I guess I'll double check everything again

d-bo

still sounds like it's vacuum line related. that loud pop you heard could have possibly been boost cut.

i would check all of your lines again and again. where is your boost gauge pulling vacuum from? what about your wastegate and boost controller?

UCF_S2K

I'm going to recheck all of my lines again tomorrow. The car only backfired a few weeks ago when I had the problem, but I found 2 burnt vacuum lines which I replaced and since then it hasn't backfired.

I could be wrong, but I believe the boost gauge is pulling vacuum from the coupler between the intake manifold and the intercooler piping.

If it was a vacuum problem, wouldn't the car be driving differently? The car drives exactly the same as it did when the gauge was reading boost properly and it still builds pressure to be released by the BOV during hard shifts. This leads me to believe there is not a vacuum problem, but I could be wrong

tx2K

So, you are saying that your boost gauge is stuck at -14 and doesn't move at all now? Check all the wiring.

I would also just replace all of your wastegate lines just to be sure.

Also, what do you mean that your boost gauge is pulling vacuum from the coupler? That sounds odd to me... Just "T" into a normal vacuum line.

Also, you should be able to hook up your laptop and view/data log your vacuum/pressure to rule out the gauge.

Im still learning as well, but thats where I would start. Good luck