Boost acting weird and i git fuel cut

[topdownturbo]

Ok so. I have a 98 spyder GS-T. Previous owner put on a 14B full 3"ebay exhaust (no cat), hard IC pipes, open cone airfilter,1G bog (crushed), and hard intake pipe. No MBC

I have maybe put 100 miles on it. When I Got it, it boosted to 15psi according to the autometer gauge.I didn't notice a fuel cut problem. So I took it out today and the gauge is boosting to about 10 then snaps back to 5 or so. When I go to WOT it boosts to about 11-12 but I get fuel cut.

The gauge might be messed up but the fuel cut is for real. So how can I be boosting that high to hit fuel cut without a boost controller???

I'm going to install new gauges shortly.

 

[toppertopper]

Do a boost leak test..Before you change the gauges

 

[WES_393]

Are you using an aftermarket gauge or the stock one? The stock one is just a rough estimate based on airflow, not an actual boost gauge.I second the boost leak test, you would be surprised how big of a problem a tiny leak can be.

 

[topdownturbo]

UPDATE::
So I was hooking up some new prosport gauges and I found my problem. The gauge was teed into the line from the intake to the FPR solenoid/switch. The line to the T had came loose and was leaking boost I assume. When it would spool up past 10 psi or so I think it would blow off or leak. This would also explain the fuel cut because the FPR was not getting a good signal. I hooked up the new gauge and secured the lines really good. Low and behold I can go WOT with no fuel cut. It boosts to 15psi no problems. My only question now is, why is it boosting to 15psi with no MBC???

Thanks guys!!

 

[topdownturbo]

Update on the Update:

So I thought my fuel cut was fixed but a full throttle run today proved otherwise
I think I have a therory. Im getting some serious boost creep. The boost control is factory but the exhaust is so large and unrestricted that it over boosts to 15 psi and spikes to near 18..
Im going to add a catalytic converter to the 3" Exhaust and try to give it some restriction. Maybe get a Adjustable Fuel Pressure Regulator to add some more fuel.

So what do you guys think I should do?

 

[99ECLIPSEGSXDSM]

If the boost controller is factory change it out to a hallman! Theyre plenty of ways to fix boost creep. Putting a cat in might help alil but I've never herd of it completly take the creep away. Port the flapper on the internal wastegate or buy a open dump o2 housing. There plenty of ways but those are the most used

 

[topdownturbo]

MORE UPDATES:

Yesterday I welded in a cat to the downpipe and fixed a couple exhaust leaks. Then I did a boost leak test.. Right away I found that the boost reference tube that is plumbed into the lower IC pipe had been leaking A LOT of boost.. ONce I got that fixed i was able to build pressure in the system to test smaller leaks. I found that the weld on the J pipe was leaking through a pin hole in the weld in self. After welding that up I pressurized again and heard more leaks near the intake but I was running out of day light so I had to stop there.

After taking the car for a ride I found a few noticeable differences. The exhaust leaks were fixed and the exhaust sounded way better and a little quieter.. I also noticed that the boost came on a lot lower in the RPMs and maxed out at about 14-15psi. Plus I didnt hit Fuel Cut and full throttle anymore and I can hear the BOV slightly now.. THat might be from the quieter exhaust though??

So I'll check for more boost leaks later but its way better than when I started.

 

[topdownturbo]

Yeah so I have fixed the major boost leaks and am still tracking down smaller ones. I thought I was out of the woods until today. I went from a dead stop to WOT and was doing great until my automatic shifted from 1st to second. Once the tranny shifted my bost spiked to about 22psi from its normal 15-16 psi.. that was weird but about a second later I got fuel cut after the boost settled back down to 15psi in second gear. Then when it shifted from 2nd to 3rd the same thing happened. Boost spike to 22psi on the shift and then fuel cut.

So????? How do I fix this or is this the problem for an automatic when running near max boost for my setup?

 

[havlc2u]

Yeah so I have fixed the major boost leaks and am still tracking down smaller ones. I thought I was out of the woods until today. I went from a dead stop to WOT and was doing great until my automatic shifted from 1st to second. Once the tranny shifted my bost spiked to about 22psi from its normal 15-16 psi.. that was weird but about a second later I got fuel cut after the boost settled back down to 15psi in second gear. Then when it shifted from 2nd to 3rd the same thing happened. Boost spike to 22psi on the shift and then fuel cut.

So????? How do I fix this or is this the problem for an automatic when running near max boost for my setup?

Your issue sounds similar to mine I have a prosport mbc I think is the issue. Not sure are you running a mbc?