Still having issues with my GN

[turbodiesel6_6]

To make a long story short i will try and explain everything thats happening, i was having what i believe was an intake backfire going into boost, so i talked to Eric from turbo tweak and he recommended 42lb injectors, i replaced at that time also the injector harness, and hotwired the fuel pump and put in a walboro pump. With the fuel pressure set at 43psi with the line off i got the back fire before 10 psi of boost, more like 7, so i turned up the fuel pressure a little more to 46psi with the line off, got a little more boost 12 to 13 psi before the backfire. So then went to the translator and turned up the wot adjustment to 6% rich, no i can get to about 15psi without a backfire. My problem is, it doest feel like the car is pulling that hard, my Duramax would smoke it at this point. The car has a little over a 100,00 miles on it. I hear what i think is ticking comming from the passenger side valve cover, but havent opened it up yet. Brian from Gbody parts told me it could be valve springs weak or timing chain. Not that im disbelieving that, but if thats true wouldnt it be a good idea for a rebuild? I live near Columbus Ohio, and im not aware of any buick turbo engine builders around, i just dont want anyone inside this engine! Maybe someone here has some ideas and some advice for me... everyone in the buick community has been awesome... thank you for keeping this great vehicle alive with info..... i just wanna be happy with the car, all ive done is work on it the last two years to get it to this point. I will try and get some scan readings off of the car while warm, but the last time i scanned everything looked awesome. Sorry this post was so long, and thank you in advance!!!

 

[robertmee]

What are your RPMs getting to at WOT? I think if the car is falling on its face at higher RPMs that's indicative of weak valve springs.

If its not pulling hard at all, maybe all the fuel adjustments you've made is making it run too rich. I know you did that to eliminate the backfire, but perhaps you've masked one problem and introduced another.

Take this advice w/ a grain of salt as I too am learning about these engines having been more used to chevy small block builds.

 

[TurboBuRick]

Worn cam?

Pull the valve covers and start the car. See if all the rockers are moving equally. I would bet you will find some not moving much.

 

[1987gndave]

I was having the same problem with it popping threw the intake and exhaust ...i changed everything ..... turned out to be a cracked header on the drivers side ,,was cracked bad enough to suck in un metered fresh air and throw off the o2 sensor ... got it welded 300 miles later still running like a champ....just something for you to check out ...

 

[turbodiesel6_6]

I have checked the exhaust headers and have seen that they have been welded up at one time or another, but dont see any new leaks, maybe i should do the gm top clean treatment and see if there are any new leaks?? I can see having to add more fuel to compensate for the exhaust leak.

 

[aminga]

Scan tool Data?

 

[mikestertwo]

pull the valve covers and start the car. See if all the rockers are moving equally. I would bet you will find some not moving much.

+1

 

[Dabigguy]

Check the plug wires.

 

[charlief1]

Scan tool Data?

I agree Al. Where's the data.