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1985-1998 [Subscribe to Daily Digest] |
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Maybe there is one out there but I have yet to find it!
I would like your help in creating such a guide. I have been plagued by "base boost only" since I purchased my 1997 Aero 5-speed (98,000KMS). Hours and hours pouring over posts leads to some very good tips but also fills ones head with bad tips, half truths or otherwise very vague reponses.
Based on countless posts I determined my BPC valve was defective because I removed the "W" hose from the valve and went from base boost (1/2 in the yellow) to boosting into the top of the red (and even to the fuel cut-off point). I also performed an ohms test and found my old BPC valve readings are left/centre = 3.0, right/centre = 13.6 and left/right = 16.1 The correct reading should be around the following: both left/centre and right/centre = 3.0 ohms. Left/right read 5.3 ohms.
All indications pointed to replacing the BPC valve and all would be well. I did replace it and absolutely nothing changed.
The trouble shooting steps and questions I have are as follows:
1) Remove the "W" (waste gate) vacuum hose from the BPC valve. If attain full boost and even fuel cut-off, your Turbo Charger and waste gate rod are in working order and should not be the problem.---true or false?
2) Borrow a working BPC valve. If this improves boost then your original is most certainly defective and a new one will fix the problem...you have gotten off relatively easy. ---true or false?
3) Check all vacuum lines for leaks. Replace as necessary and retest
4) check operation of the PVC valve off the valve cover. Male sure you can blow air though the PVC valve in the direction of the intake manifold connection. Make sure you CANNOT blow air in the other direction, towards the valve cover end of the connection. If suspect, replace and test operation of boost.---true or false?
5) Check brake pedal switches (there are two, upper is cruise control and lower is brake light activation) If your brake lights operate normally, this is likely not the problem and there is no need to test the switch any further---True or False???
If you notice your brake lights stay even after you take your foot off the pedal, the switch is defective and could likely be a cause of base boost only. Replace and retest boost. This is the only indication of a problem with the brake light switch---True or False???
6) Check operation of cruise control system. If it works fine, this is likely not the cause of the problem so move on---True or False???
If cruise control does not work properly, check operation of the clutch pedal switch (there is one). If this is faulty, it is likely the cause of the base boost problem. This is the only indication of a problem with the clutch pedal switch. Replace and retest---true or false???
7) Check reading of 3-wire cable harness end of BPC valve harness. The reading should be xx , yy and zz. If not, it is likely a problem with the ECU. Test transistor A, B and N. The readings should be xx, yy, zz. If not, replace defective resister and retest system. ---true or false.
This is my work in process thus far, please comment and make adds, deletes and changes where needed.
Thanks
Norm
1997 Aero 5 speed 98,000kms
1989 900TC 5 speed 165,000lms
1987 900TC 5 speed (converted) 248,000kms
posted by 207.6.246...
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