Resolved 2G Loss of power/sputtering at 3k+

[Talyn]

Just installed a 20g turbocharger, with an FP manifold, set at 13 psi, also replaced the timing belt, and had the head off as well. I don't have the ignition timing dialed in yet (no timing light), but I have it enough to run ok, it does fine below 3k rpm, but like clockwork it starts sputtering right at 3k rpm which is also right when the boost starts coming on.
Idk if I am hitting fuel cut, or my timing is off too much, I read that the stock fuel system can cope with 16 psi (as soon as I get it running right I am upgrading the fuel system, babying it in the meanwhile and keeping it at stock (for my turbo) wastegate setting of 13 psi.), and it seems unlikely that I could be hitting fuel cut at 3k rpm. But it does happen right when boost starts coming on.

Would appreciate some input, I finally have my baby running again, but it still has too many kinks to drive other than for testing/diagnosing

 

[nuclearr]

Do a boost leak test.

 

[majik2k5]

Focus on boost leaks before you start looking at your timing. How many miles did you put on the car after you had the head off? Enough for the head gasket to seal up? Did you revisit the studs and tighten them? You would probably notice if it wasn't sealed before 3k, but it could still be a contributing factor.

Also, something to keep in mind pertaining to your fuel system, 16psi on a stock turbo is not the same as 16psi on a 20g. There are numerous factors that play into finding the right amount of boost that fits with your fuel system. I'd keep it turned down and start with your basic checks to try to resolve your issue.

Let us know what you find.

 

[GSTurbo1]

BLT and tune

 

[Talyn]

Thanks for the input, its not the HG, I am sure of that. It's probably a boost leak, or possibly timing or related to the high/fluctuating idle, but at least now I have a little more direction, probably going to have a dealership figure it out though....I am moving in 4 days and don't have time or energy to mess with it, that and I am getting frustrated with the never ending issues I've been having with cars for the past year. Right now I'd rather pay for it to be someone else's problem =/.

 

[fantom73088]

I've had idle issues caused by the leaking throttle body and also the same running issue you have described. I would rec-amend a boost leak test and even check your mass air flow sensor there could also be a fault there. Are there any codes?

 

[Talyn]

Update, got the car back from the dealership today, they were unable to figure out the problem, they are hung up on informing me that I need a crank sensor for it to run right, no matter how much I told them the CAS is setup to provide the crank signal like in a 1st gen.

This is really frustrating the hell out of me, idk wth the problem could possibly be, no check engine light, timing is good, I have my plug wires switched around as per CAS mod...
Is there a way to check that the crank signal off the CAS is any good?
And boost leak seems unlikely, its not quite hitting boost, and the throttle body is in no different condition than when i bought the car. Tech seemed pretty certain it wasn't a boost leak either.

More update:
I had a chance to drive it a bit more(on the way home) and have some additional info, I was having to shift at 2k rpm in every gear but first, first I was able to get up to 3k, and once or twice broke past 3k, and hit boost and ran right for a split second to 4k, and then sputtering /loss of power bs again, and I have no check engine light other than intermittent p1105 fuel pressure solenoid, but I am not convinced that that is the problem, because I think its had that code as long as I've had it.

 

[Talyn]

Boost leak =/ The pipe was still inside the coupler, and since all the couplers were tight for so long it was mushroomed a little bit, and the clamp was completely loose, but all the slack was on the underside where it wasn't noticeable, I only found it because I was unbolting the CAS to try checking the timing after I had it off again. Bumped against the pipe, and realized it moved more than it should have if it was tight, grabbed it and wiggled it a bit to confirm, sure enough... it was a coupler all this time =/