engine runs good but to chokes when trying to boost

[tc86gn]

engine runs good but chokes when trying to boost

I have been building this thing for a couple of years now and I finally got it running and cant tune my boost or something. any good articles on this topic? any help is appreciated. Everything checks out fine with a scan tool and runs crappy when you put a foot to it and try to build some boost. then the boost cuts off and it runs just like a regular v-6. I am a pretty good mechanic but new to tuning a turbo v-6.


Tom

 

[TurboDave]

Can you be any more descriptive of the problem? Sounds a little vague. Just from what you've said so far though, it almost sounds like the coil pack or module might be starting to go bad.

 

[tc86gn]

I have got the typical setup. .030 forged pistons, ta49, green stripes, 70 mm tb,etc..... just started it up this past weekend. I have set everything according to manufacturers specs and to the info on gnttype.org and the service manual. My first question would be. what is a good starting length of the adjusted wastegate rod on a TA 49. I think this would help me a little to a good starting point. The more I drive it ,the more I was leaning toward your ignition suggestion. example: driving 55 MPH at 1800 RPM is fine but when i accelerate to say 3000RPM it starts cutting out but my fuel pressure gauge is still reading good. This is just going down the road with tranny in 3rd to get higher rpm but no boost applied. Then today for some reason i accelerated and it took off like a rocket. Never did it again. It will build boost and starts cutting out sometimes worse then other times. there is no backfire. It is a new motor so I have been not pushing it too hard till I get at least 500 miles on it. The computer has no codes stored and is working fine. Thanks for your time. As I said before, I am a pretty good mechanic but am still learning about these cars.


Tom

 

[sixgun86gn]

does it still have the stock cat? When I first got my car it wouldnt build boost and cut out ,but the fuel pressure was good.It ws a bad cat.Also one time I tried turning the boost up and had to do something before I hooked up the wg rod and that caused a no spool problem.Is your wg all the way closed?

 

[tc86gn]

new cat. wastegate closed.

 

[UNGN]

What do you consider Good fuel presure ?

Stock rod length is 5.25" from the hole to the face of the actuator. Assume that as 14 psi. Every .050" shorter is about 1 psi of boost.