Not another boost problem thread
Not another boost problem thread
Hi This is my first post after much searching and have found much help but have not managed to fix the problem yet. I have a 92 fd bone stock, and i kinda want to keep it that way. When i bought the car i figured a seat of the pants boost test was enough to tell me the turbos were working. Well guess what, i was wrong. After driving it for a month i got a pod and installed a boost guage and found out my secondary turbo doesn't seem to work at all. First thing i did was take the compressor tube off to do a visual inspection of end play, And it's good, but i wanted to make sure it was good before i kept driving it.
Since then i have had very little time to play with it. But i bought a vacuum/pressure tester and printed off the autosportracetech troubleshooting pages and started working down the list. This is one of the more complicated and obscure systems out there and i would really like to figure it out, but it could take some time, it's a lot for me to wrap my head around.
Ok here's what my car's actually doing; Boosts up solid around 2000 rpm's or less, 11psi, And then as soon as 4.5k hits it tapers off, 8 psi, by 5 k 5psi, by 6k 0 to 2 psi, then nothing.
I got the idea to try a run from 5000 k with a vacuum condition (no boost) to see if this will spool my secondary turbo. Sure enough, Full boost 10 psi all the way to redline . So i'm led to believe i have a leaky vacuum tank/one way check valve. But i really don't know what i'm doing.
I have a dual pod and dual boost/vacuum guages until i get my problem fixed i figured the second guage might come in useful for troubleshooting.
Since then i have had very little time to play with it. But i bought a vacuum/pressure tester and printed off the autosportracetech troubleshooting pages and started working down the list. This is one of the more complicated and obscure systems out there and i would really like to figure it out, but it could take some time, it's a lot for me to wrap my head around.
Ok here's what my car's actually doing; Boosts up solid around 2000 rpm's or less, 11psi, And then as soon as 4.5k hits it tapers off, 8 psi, by 5 k 5psi, by 6k 0 to 2 psi, then nothing.
I got the idea to try a run from 5000 k with a vacuum condition (no boost) to see if this will spool my secondary turbo. Sure enough, Full boost 10 psi all the way to redline . So i'm led to believe i have a leaky vacuum tank/one way check valve. But i really don't know what i'm doing.
I have a dual pod and dual boost/vacuum guages until i get my problem fixed i figured the second guage might come in useful for troubleshooting.
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