I have recently installed a turbo and am having some issues with it not boosting past 4lbs. I am running a basic set-up with 12:1 fmu, 255 Walbro on stock injectors. It was running rough for the first day or two so I checked the gap on the plugs and set them to .034. Once I did that it boosted to 7lbs and was running awesome, no hesitations or anything. The exhaust manifold gasket started to leak(I should have known since it had a little kink in it from the start). I replaced that as well as the gasket for the manifold to turbo gasket. It is no longer leaking yet I am still only getting to about 4lbs of boost and it stutters. I have checked for leaks throughout the intercooler piping and everything is tight. The top vent tube for the wastegate was hitting the hood and after reading about this in the forums I found it is not necessary to have it on there. Any idea's would help.
thanks
Justin

had the same problem. Just fixed it today, idk if its the same issue, but my FMU was installed incorrectly.

Make sure the wastegate is sealed to the manifold properly if you are running an external wastegate. The bolts on mine backed out once and wouldn't get me past 3lbs. Also, what are you using to trick the ecu? If you're using a missing link, check the little filter that sits in the side. If your ecu starts seeing positive map, it'll F with the timing and you won't be building much boost, if any.

I CONTRIBUTED TO THE WIKI!
ah... turbo. I love the turbo, the boost, the speed, the sound.
and its all better when you do it yourself. cheaper too.

The wastegate is exactly what it was. It is leaking from the bottom side. I don't need to trick the computer due to the fact that it is a 95. Thank you for the quick response, now I will just have to wait for the gasket to come in

Sweet! Score for m Glad I can help & good luck.

BTW, what I did when mine backed out, went to lowes and picked up two allen head bolts (easier to tighten) and two lock washers to fit, cranked down on them and haven't had problems since.

I CONTRIBUTED TO THE WIKI!
ah... turbo. I love the turbo, the boost, the speed, the sound.
and its all better when you do it yourself. cheaper too.

tightened everything up and now the wastegate is getting stuck open at about 4-5 psi. I am thinking that I have a leak in the exhaust as well. Going to do a boost leak check once again hopefully this week/weekend. I can hear the wastegate shuttering and it pretty much falls on its ass as soon as it hits 4-5 psi of boost

What size/ color spring is in the wastegate?

I CONTRIBUTED TO THE WIKI!
ah... turbo. I love the turbo, the boost, the speed, the sound.
and its all better when you do it yourself. cheaper too.

It is an 8lb spring. I had hit 7lbs a couple times and then a melted a vacuum line which has since been replaced. I was having the same troubles and gapped the plugs to .032 and then that is when I got 7. I just rechecked them today to make sure to no prevail. I am going to have to do a boost leak check this weekend because the exhaust is sealed up tight(already checked). Whenever I get into the throttle it seems like the wastegate is fluttering so to speak at about 4-5lbs. Once again I can't see under the hood when I am driving so a boost leak check would give me much more detail. Thanks for the response.