boost proble PLEASE help me trouble shoot..
11-29-01, 12:27 AM
#1
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boost proble PLEASE help me trouble shoot..
in first and 2nd sometimes third gear boost under wide open throttle only gets up to 5-8 psi max. very strange because it also gets up to 11-13 psi its wierd i never know how much psi i am going to get when i floor it?? help me attain the 10-8-10 boost i should have..only mods are a downpipe...havent replaced y-pipe yet or check to replace vacume hoses, could it be either of the two..also i have new turbos....3,000 mi. on them?
also i have this damn proble with the e-brake light coming on everytime i hit a bump??
also i have this damn proble with the e-brake light coming on everytime i hit a bump??
11-29-01, 04:15 AM
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e-brake light might just be that the bump jarrs the e-brake handle enough that it loses contact with the electrical switch just enough to turn the light on. sorry, i am not sure about the turbos 
check all vacuum lines and hoses/pipes is the first thing i can think of, other than that, not real sure...
check all vacuum lines and hoses/pipes is the first thing i can think of, other than that, not real sure...
11-29-01, 09:28 AM
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I pulled this from the archives from a boost problem thread:
My advice is to lean toward what KZ1 is saying, test the control system and look for the basics.
My additional advice:
1. Look for loose hoses and couplers.
a. The Y-Pipe hoses (the 1" hoses should not turn")
b. Tighten hose clamps on all the couplers.
c. Test drive.
2. Look at the control system
****Highly recommend getting the Sop Manual*****
a. Replace vacuum lines if you haven't already (all of them!)but first see note below step 2-f
b. Test drive. If not cured, go to the next test.
c. Cut to the chase. Test the Turbo Control Actuator (TCA) by applying manual pressure and vacuum to the two metal tubes that shoot straight up between the coolant filler neck and alternator. Look under the car for movement of the Turbo Control when you release the pressure or vacuum. The rod should stay fully retracted for as long as there is pressure or vacuum present. No exceptions! If good then go to step "d" but if not, then try hooking up your vacuum pump directly to the TCA to bypass the metal tubes and hoses. If still bad, replace TCA.
d. Test to see that pressure holds in the black plastic pressure chamber next to the upper intake manifold by removing one of the two hose and tapping directly into the chamber leaving one of the hoses still attached and add pressure. Trade the leftover hose out with the one still attached to the chamber and test again. There should be no pressure loss with either hose still attached.
If there is a loss of pressure while one hose is attached and not the other then you can narrow the pressure loss to the hose that was leaking and then further determine if it is a check valve, or a leaking solenoid or hose.
e. Do the same test on the vacuum chamber found next to the power steering. There should be no vacuum loss with the tank hooked up directly to the vacuum pump only. Note: The tank will take a few pumps to remove the air in it. Test
the hose that was attached to the chamber that leads to the solenoid rack by applying vacuum to it. There should be no loss of vacuum. If so, then there is a possible bad check valve, hose, or solenoid leak. Test the check valve first and if good then move on to test f.
f. The vacuum chamber is shared by the Turbo Control Actuator (TCA) solenoid, Charge Control Actuator (CCA) & solenoid, and the Charge Relief Valve (CRV).
A quick end-of-the-line test for leaks with the CCA is to pull the vacuum line off the CCA and hook it to a vacuum tester and then turn the car on. You should see vacuum around 15 to 22 inches. Leaving the tester connected, turn the car off but leave the key on "run". You should see vacuum stuck between the tester and the vacuum tank via the solenoid. There should be no vacuum
loss until the key is off. The Charge Relief Solenoid is similar in testing with the exception that there should be vacuum held at the CRV even while the car is off. If you see vacuum loss here then you have either a bad hose connection between the CRV
and solenoid, a leaking solenoid, or a leaking vacuum side hose between the CCR Solenoid and CRV Solenoid. As for the TCA vacuum solenoid, there should be no vacuum loss when you hook your vacuum pump to the opposing metal tubes that we used in test “C”. Simply pump out the air in either hose and look for any vacuum loss. If there is a loss in vacuum then you either have a bad hose connection to the respective solenoid or you have a leaking solenoid. Repair hose or replace solenoids as necessary.
Note: Remember, if you have access to any of the solenoids, you should test the solenoids for vacuum loss and switching capabilities by applying 12 volts directly to the switches while vacuum is present. There should be no loss of vacuum or pressure between the “L” like nipples on the solenoid when there is no voltage. There should be flow between the nipple pointing up, and the metal nipple pointing to the rear of the solenoid when there is no voltage present and no flow when voltage is. Replace the solenoids if defective.
g. Repeat step 1.
Why bother? Because the control system is the number one suspect for improper secondary boost. Some people have posted on the possibilities of cross interference between the signals of both the wastegate solenoid and the prespool solenoid, and perhaps this is an avenue to be further looked at, but the prime problem with these cars can be generalized as poor control management. Too many switches goofing around and too many hoses popping off. To find the cure of problem you must methodically eliminate every possibility. With these cars there are several, and you will only be doing yourself a favor by carefully eliminating each one, one by one.
Or you could pay someone else who knows what they are doing to do it for you. Ughh!
My advice is to lean toward what KZ1 is saying, test the control system and look for the basics.
My additional advice:
1. Look for loose hoses and couplers.
a. The Y-Pipe hoses (the 1" hoses should not turn")
b. Tighten hose clamps on all the couplers.
c. Test drive.
2. Look at the control system
****Highly recommend getting the Sop Manual*****
a. Replace vacuum lines if you haven't already (all of them!)but first see note below step 2-f
b. Test drive. If not cured, go to the next test.
c. Cut to the chase. Test the Turbo Control Actuator (TCA) by applying manual pressure and vacuum to the two metal tubes that shoot straight up between the coolant filler neck and alternator. Look under the car for movement of the Turbo Control when you release the pressure or vacuum. The rod should stay fully retracted for as long as there is pressure or vacuum present. No exceptions! If good then go to step "d" but if not, then try hooking up your vacuum pump directly to the TCA to bypass the metal tubes and hoses. If still bad, replace TCA.
d. Test to see that pressure holds in the black plastic pressure chamber next to the upper intake manifold by removing one of the two hose and tapping directly into the chamber leaving one of the hoses still attached and add pressure. Trade the leftover hose out with the one still attached to the chamber and test again. There should be no pressure loss with either hose still attached.
If there is a loss of pressure while one hose is attached and not the other then you can narrow the pressure loss to the hose that was leaking and then further determine if it is a check valve, or a leaking solenoid or hose.
e. Do the same test on the vacuum chamber found next to the power steering. There should be no vacuum loss with the tank hooked up directly to the vacuum pump only. Note: The tank will take a few pumps to remove the air in it. Test
the hose that was attached to the chamber that leads to the solenoid rack by applying vacuum to it. There should be no loss of vacuum. If so, then there is a possible bad check valve, hose, or solenoid leak. Test the check valve first and if good then move on to test f.
f. The vacuum chamber is shared by the Turbo Control Actuator (TCA) solenoid, Charge Control Actuator (CCA) & solenoid, and the Charge Relief Valve (CRV).
A quick end-of-the-line test for leaks with the CCA is to pull the vacuum line off the CCA and hook it to a vacuum tester and then turn the car on. You should see vacuum around 15 to 22 inches. Leaving the tester connected, turn the car off but leave the key on "run". You should see vacuum stuck between the tester and the vacuum tank via the solenoid. There should be no vacuum
loss until the key is off. The Charge Relief Solenoid is similar in testing with the exception that there should be vacuum held at the CRV even while the car is off. If you see vacuum loss here then you have either a bad hose connection between the CRV
and solenoid, a leaking solenoid, or a leaking vacuum side hose between the CCR Solenoid and CRV Solenoid. As for the TCA vacuum solenoid, there should be no vacuum loss when you hook your vacuum pump to the opposing metal tubes that we used in test “C”. Simply pump out the air in either hose and look for any vacuum loss. If there is a loss in vacuum then you either have a bad hose connection to the respective solenoid or you have a leaking solenoid. Repair hose or replace solenoids as necessary.
Note: Remember, if you have access to any of the solenoids, you should test the solenoids for vacuum loss and switching capabilities by applying 12 volts directly to the switches while vacuum is present. There should be no loss of vacuum or pressure between the “L” like nipples on the solenoid when there is no voltage. There should be flow between the nipple pointing up, and the metal nipple pointing to the rear of the solenoid when there is no voltage present and no flow when voltage is. Replace the solenoids if defective.
g. Repeat step 1.
Why bother? Because the control system is the number one suspect for improper secondary boost. Some people have posted on the possibilities of cross interference between the signals of both the wastegate solenoid and the prespool solenoid, and perhaps this is an avenue to be further looked at, but the prime problem with these cars can be generalized as poor control management. Too many switches goofing around and too many hoses popping off. To find the cure of problem you must methodically eliminate every possibility. With these cars there are several, and you will only be doing yourself a favor by carefully eliminating each one, one by one.
Or you could pay someone else who knows what they are doing to do it for you. Ughh!
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