7 - 5 - 2 Boost Pattern
12-02-2003, 08:36 AM
#1
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Join Date: Nov 2003
Posts: 5
'92 Jap import 3rg Gen RX7.
Had the car a month or so and fitted a boost guage yesterday, and got a 7 - 5 - 2 Boost Pattern. Now i know why the car doesn't feel too fast
The car has twin K&N filters and a downpipe (i think). Everything else looks stock. I have replaced the inlet extension manifold gaskets recently but was wondering what else to look for which would indicate the crappy boost pattern.
I am new to the rotary world but have had my head under the bonnet (hood!) more than behind the wheel.
Blocked main cat? If so, is it okay to replace and will i need to alter the ECU?
Any help much appreciated.
(the forums in the UK are a bit crap.... )
Had the car a month or so and fitted a boost guage yesterday, and got a 7 - 5 - 2 Boost Pattern. Now i know why the car doesn't feel too fast
The car has twin K&N filters and a downpipe (i think). Everything else looks stock. I have replaced the inlet extension manifold gaskets recently but was wondering what else to look for which would indicate the crappy boost pattern.
I am new to the rotary world but have had my head under the bonnet (hood!) more than behind the wheel.
Blocked main cat? If so, is it okay to replace and will i need to alter the ECU?
Any help much appreciated.
(the forums in the UK are a bit crap....
12-02-2003, 09:54 AM
#2
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Join Date: Jan 2002
Location: New Jersey
Posts: 3,928
you need to generate 8psi for the secondaries to properly boost..
check the double throttle..make sure thats not stickin
check the coupler for the ypipe..make sure theres no leak there
check your precontrol solenoid..
check the double throttle..make sure thats not stickin
check the coupler for the ypipe..make sure theres no leak there
check your precontrol solenoid..
12-02-2003, 10:04 AM
#3
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Join Date: Jul 2003
Location: Baltimore, Maryland
Posts: 55
You are having a typical problem for an FD.
Before looking into solenoids and throttles bodies, check all hoses from the turbo outlet to the intake inlet. 98% of the time it is a small crack in a hose. Inspect them very carefully. When the line is not under boost it can be had to find.
If you determine that it is not a crack in a hose. Then move to the turbos solenoid controls.
Before looking into solenoids and throttles bodies, check all hoses from the turbo outlet to the intake inlet. 98% of the time it is a small crack in a hose. Inspect them very carefully. When the line is not under boost it can be had to find.
If you determine that it is not a crack in a hose. Then move to the turbos solenoid controls.
12-02-2003, 10:57 AM
#5
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Location: S.w. Florida boring ass ft myers to be exact. where the old people come to die
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good info above. my problem was the hose going to the bottom of the intercooler was cracked. next one was the hose coupler on the y pipe..and some rotten vacuum lines.
12-03-2003, 02:37 AM
#6
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Checked all the inlet hoses (1 to CRV, 1 to Bypass) and they had tiny cracks where the hoses joined the turbo assembly. Cut the hoses down and reinstalled them, no difference
Checked the 'Y' pipe coupler, no problem there...
Checked all vacuum hoses in Rats nest.
Disabled the double throttle last week.
Will check the hose to the bottom of the intercooler and the vac line to the vacuum chamber tonight.... Will let you know.
I checked a few previous threads and thought that the 2 solenoids behind the pressure chamber may have been swapped round, so i swapped them and took the car out for a run. It ran rough at idle but made a solid 5 psi to redline. By doing that am i disabling the ECU control of the 2nd turbo?
How do i check the function of the solenoids?
Many thanks
Checked the 'Y' pipe coupler, no problem there...
Checked all vacuum hoses in Rats nest.
Disabled the double throttle last week.
Will check the hose to the bottom of the intercooler and the vac line to the vacuum chamber tonight.... Will let you know.
I checked a few previous threads and thought that the 2 solenoids behind the pressure chamber may have been swapped round, so i swapped them and took the car out for a run. It ran rough at idle but made a solid 5 psi to redline. By doing that am i disabling the ECU control of the 2nd turbo?
How do i check the function of the solenoids?
Many thanks
12-03-2003, 08:39 PM
#7
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Join Date: Jun 2002
Location: La Plata, Maryland
Posts: 9,725
God I thought I would never see a "I have a 3-6-8 boost pattern what do i do" thread.
Anyway sounds like you are not getting any secondary boost. You need to at least ins[pect the charge relief valve and the large black hose that connects it to the Y pipe assmebly. The charge control valve might also be sticking.
Look into anything controlling secondary boost..
Anyway sounds like you are not getting any secondary boost. You need to at least ins[pect the charge relief valve and the large black hose that connects it to the Y pipe assmebly. The charge control valve might also be sticking.
Look into anything controlling secondary boost..
12-04-2003, 08:17 AM
#8
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Originally Posted by Fd3BOOST' date='Dec 3 2003, 09:39 PM
Look into anything controlling secondary boost..
which is regulated by the precontrol solenoid..
are we dealin with factory vacuum lines here jon...
12-04-2003, 12:55 PM
#9
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Location: La Plata, Maryland
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Originally Posted by amp' date='Dec 4 2003, 06:17 AM
but hes not generating enough psi on the primaries for proper transition to the secondaries...
which is regulated by the precontrol solenoid..
are we dealin with factory vacuum lines here jon...
which is regulated by the precontrol solenoid..
are we dealin with factory vacuum lines here jon...
He is still getting transition as his boost pattern clearly shows.
12-05-2003, 04:06 AM
#10
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Join Date: Nov 2003
Posts: 5
i am running on factory / aftermarket vacuum lines (some are blue).
Boost guage shows 17hg at idle which i assume is normal.
I have visually checked the charge relief valve and the large black hose that connects it to the Y pipe assemebly (1 inch diameter), and cut a small crack out with no difference. Can i check the CRV by swapping it with the ABP valve to see if there is a difference? The ABP valve is dumping boost when i let off...
I replaced the inlet hose to the primary turbo with a new pipe (from a 200SX) last night, thinking that it may be deforming under boost, no difference...
Put new hose clips on all the 1 inch pipes, no difference...
Checked all pipes to and from Intercooler...
Visually inspected primary turbo, no noticable play in shaft...
Is it time to go non sequential?
Boost guage shows 17hg at idle which i assume is normal.
I have visually checked the charge relief valve and the large black hose that connects it to the Y pipe assemebly (1 inch diameter), and cut a small crack out with no difference. Can i check the CRV by swapping it with the ABP valve to see if there is a difference? The ABP valve is dumping boost when i let off...
I replaced the inlet hose to the primary turbo with a new pipe (from a 200SX) last night, thinking that it may be deforming under boost, no difference...
Put new hose clips on all the 1 inch pipes, no difference...
Checked all pipes to and from Intercooler...
Visually inspected primary turbo, no noticable play in shaft...
Is it time to go non sequential?