Boost problems, won't boost past 9psi, FI Guru's need your thoughts
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Boost problems, won't boost past 9psi, FI Guru's need your thoughts
Ok my friend is having a boost problem on his 3SGTE MR2, I know its not a Honda, but hoped that all you FI Guru's can give your input and thoughts.
Ok, just rebuilt a fresh motor running 8.5 JE slugs. Running a retrimmed factory turbo, stock down pipe. Boosting about 6 psi to 7 psi without use of boost controller. Now with the profec, we tried increasing boost but no matter how high we set it, it only boosts to max of about 9psi. We can hear the turbo screaming, but won't boost past 9psi and doesn't feel that strong. (followed proper installation and programming of the profec "P1 3rg gear run and P2 3rd gear run")
Factory timing on 3SGTE is 10 degrees, currently set at about 13 degrees, 3 degrees advance in timing. Plugs gapped to .025".
We put fresh 7 heat range plugs, it would not boost past about 6psi, the stock gap of the plugs were about .044", we then regapped the plugs to .025" and we were able to boost back up to 9psi, but not higher.
Sometimes, the boost will go to 9psi and drop down slowly to 6psi, it won't hold at 9psi. This occurs from time to time, but not all the time.
Checked compression, #1 130psi, #2 150 psi, #3 150 psi, #4 150 psi. Leakdown showed the intake valve was leaking slightly due to poor seating. Don't ask, Friend misplaced 1 intake valve and when he replaced it with another from a spare head, he did not take his time to lap the valves properly (rush job).
What could be the problems? Could you provide some thoughts so we can try to trouble shoot the situation.
Could the problems be caused by:
1) Is the timing advanced too much?
2) Leak on #1 intake valve?
3) Sparks being blown out, need to install aftermarket ignition?
4) Profec malfunction?
5) Vacuum leak?
6) Stock down pipe need to replace to aftermarket?
Thanks
Ok, just rebuilt a fresh motor running 8.5 JE slugs. Running a retrimmed factory turbo, stock down pipe. Boosting about 6 psi to 7 psi without use of boost controller. Now with the profec, we tried increasing boost but no matter how high we set it, it only boosts to max of about 9psi. We can hear the turbo screaming, but won't boost past 9psi and doesn't feel that strong. (followed proper installation and programming of the profec "P1 3rg gear run and P2 3rd gear run")
Factory timing on 3SGTE is 10 degrees, currently set at about 13 degrees, 3 degrees advance in timing. Plugs gapped to .025".
We put fresh 7 heat range plugs, it would not boost past about 6psi, the stock gap of the plugs were about .044", we then regapped the plugs to .025" and we were able to boost back up to 9psi, but not higher.
Sometimes, the boost will go to 9psi and drop down slowly to 6psi, it won't hold at 9psi. This occurs from time to time, but not all the time.
Checked compression, #1 130psi, #2 150 psi, #3 150 psi, #4 150 psi. Leakdown showed the intake valve was leaking slightly due to poor seating. Don't ask, Friend misplaced 1 intake valve and when he replaced it with another from a spare head, he did not take his time to lap the valves properly (rush job).
What could be the problems? Could you provide some thoughts so we can try to trouble shoot the situation.
Could the problems be caused by:
1) Is the timing advanced too much?
2) Leak on #1 intake valve?
3) Sparks being blown out, need to install aftermarket ignition?
4) Profec malfunction?
5) Vacuum leak?
6) Stock down pipe need to replace to aftermarket?
Thanks
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Re: (PrettyLude)
Also running internal actuator type turbo.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccfab »</TD></TR><TR><TD CLASS="quote">sounds like classic boost leak </TD></TR></TABLE>
What is actually boost leak and what is the cause of it?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrettyLude »</TD></TR><TR><TD CLASS="quote">i know on factory turbocharged cars, they have a solenoid, i can't remember the name, that you have to take out completely or bypass</TD></TR></TABLE>
I'll check regarding the solenoid
Keep you inputs coming
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccfab »</TD></TR><TR><TD CLASS="quote">sounds like classic boost leak </TD></TR></TABLE>
What is actually boost leak and what is the cause of it?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrettyLude »</TD></TR><TR><TD CLASS="quote">i know on factory turbocharged cars, they have a solenoid, i can't remember the name, that you have to take out completely or bypass</TD></TR></TABLE>
I'll check regarding the solenoid
Keep you inputs coming
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