Can't boost past 5psi!!!

[coolbone28]

My friend has a red top in his 89. Motor is completely stock. We got a boost gauge and realized it was only boosting up to 5psi. Then we put a MBC on it to try and turn it up. STILL only boosted to 5psi. We unhooked the vacuum to the wategate and it still only went to 5. So what in the hell could cause the boost to stay at 5psi??? My thoughts were a vac leak, but his car idles and runs good. about 18in of vac at idle. Please help.

thank you.

[Rookieca18det]

Turbo dying or maybe an exhaust leak. Good luck.

[S13240]

Probably hooked up the vacuum lines wrong.

[itsnever2fast]

i had the same problem. exhaust backpressure maybe pushing the wastegate open check the tension on from the wastegate actuator to the wastegate. tighten in up a little at a time. especialy if you can move it with 2 fingers
Modified by itsnever2fast at 3:49 PM 12/19/2006

[sssrdub]

stock exhaust? cat?side mount intercooler?

[coolbone28]

its the stock s13 exhaust with the side mount. i dont see why that would limit the psi so bad. I am starting to lean towards a bad turbo. I will have him try all the suggested problems first. Thanks for the replies. Awesome feedback. Keep 'em comin.

[89 S13 Coupe]

i had the same problem. exhaust backpressure maybe pushing the wastegate open check the tension on from the wastegate actuator to the wastegate. tighten in up a little at a time. especialy if you can move it with 2 fingers

Modified by itsnever2fast at 3:49 PM 12/19/2006

how do adjust the tension an the wastegate actuator?

[karmakaze]

how do adjust the tension an the wastegate actuator?

you can't on the stock turbo. you can rig the wastegate with spacers though to increase the tension.

[itsnever2fast]

prob a bad wastgate actuator rather than a bad turbo.

[89 S13 Coupe]

hurray, i found the problem when i did a boost leak test, it was leaking out of the intercooler jb welded it and it works fine now (temp fix till my fmic comes in)

[IDriveFords]

I a

i had the same problem. exhaust backpressure maybe pushing the wastegate open check the tension on from the wastegate actuator to the wastegate. tighten in up a little at a time. especialy if you can move it with 2 fingers

Modified by itsnever2fast at 3:49 PM 12/19/2006

I actually just read an article in a magazine that said the exact same thing. One thing you can do to try and free up the exhaust is *coughgutthecatcough* even if this doesnt help your problem it's still very good for the car. Oops my brower wasn't refreshing right so I didn't see you fixed it. You should gut the cat anyway

[89 S13 Coupe]

gutted the cat during the diagnostis

[sean58888]

sometime it might be the water temp sensor gone bad,ecu in safe mode and wont allow you to boost becasue the engine is not operating in properoperating temperture.this might be your last thing to check for if everything else is good. http://cgi.ebay.com/ebaymotors...57544