overboost

[86lance]

.alright finally got my car setup and running failry well after converting to blowthru. its an 86 lancer es with 3 inch side exit exhuast from the garret turbo,semi ported head,heavily ported exhaust manifold,semi ported intake,socketed and chipped log 86 computer to glhs specs stage one for now(thanks glhs 232!!!) stage 2 can go in at anytime. Now for the problem,im hitting over boost right around 9 psi,if i set my grainger valve a little bit lower it runs at 8 *perfectly*no boost creep whatsoever,just an initial spike to 9 then backs off to 8 and holds rock solid. Why is this thing doing this? everything has been gone thru except for the AIS motor,it couldnt cause overboost could it? i thought over boost was set at 14.7 psi? I really want to feel how this car is at 14 psi. All of my vacuum lines should be just fine,i made a good vacuum block and used goodyear vacuum lines everywhere. what could cause all of this?

[86lance]

also forgot to mention that i wasnt sure where to put this question at,so mods feel free to move it.

[86lance]

up i go!

[OmniGuy123]

What kind of boost gauge are you running?

[86lance]

sunpro cheapie thing,i checked it with a mighty vac and it was ok

[86lance]

bump

[tonyz2897]

There are a few possible causes I can think of. Some of them are a bit off the wall, but I'll list them anyway.
Bad map sensor. Could it possible be hitting 4.3 volts before the boost is actually at 14.7 psi?

What about the cal? Is it possible that the onset of cutout was set lower in that cal for some strange reason?

The last thing I can think of is cam timing. I know it's actually not cutout, but when I had the cam timing on the daytona off (advanced), it would hit a wall in the rpm range and just sort of hang there and surge. It felt like cutout but not quite as violent.

Just some food for thought.
Tony

[daytonajesse]

recheck your vac lines, I know you said you did but do it again pay special attention to any old fittings that are still there. Does it happen at the same boost level all the time? Your boost gauge may be off as well. Do me a favor and check your codes, maybe it's the asd and not overboost.

[86lance]

there are no old fittings,i just did a completely new vac system and even made up a nice brass vacuum block for everything. Whats is an asd? I have no codes. it does happen at the same level,i turn it down a bit and its just fine,worse when its rly cold though. I dont think the cal is messed up or at least it should be. And it is definately overboost,everything cuts,very violent,could the plugs be gapped too wide? And im blwing out the spark?

[daytonajesse]

If it was overboost it should store a code, asd = auto shutdown relay.

[86lance]

what would the asd relay do to cause it to feel like over boost around 8-9-10 psi? could the asd relay,cause this problem ANd a fuel pump problem?

[86lance]

also i have NO codes to speak of,not even with my no start condition,lol

[Daytona_Geoff]

when it overboost's does it like cut out like kinda surgin cause i had the same problem With mine when it was cold Never could figure it out until i ripped my motor out and my wastegate was barly attached like moviin around the wastegate arm to the turbo but the metal line or rod that goes to the wastegate and the little clip was still attached but loose check that maby could be the problem.

[Daytona_Geoff]

when it overboost's does it like cut out like kinda surgin cause i had the same problem With mine when it was cold Never could figure it out until i ripped my motor out and my wastegate was barly attached like moviin around the wastegate arm to the turbo but the metal line or rod that goes to the wastegate and the little clip was still attached but loose check that maby could be the problem. thats on a turbo II setup

[86lance]

wastegate is fine,if my wastegate was unplugged it wouldnt get any boost i thinkand i know wut overboost feels like,this has got to be overboost