Rob90AWD
Probationary Member
- 3
- 0
- Aug 14, 2011
-
New Orleans,
Louisiana
I'm trying to help a friend with a mostly-stock GVR4. I think I know what's wrong but I wanted to bounce it off the experts. I'm the original owner of a 90 Talon TSi AWD so I know my way around unmodified DSM's pretty well. His GVR4 was running fine
His description of the symptoms:
"Bob sets timing to 5 degrees. Later I leave, car feels as if it were dragging, like boost was being produced but wasn't going anywhere. After 10 mins I find myself unable to accelerate, pulling to the side of the Road using the car's momentum. It starts to overheat and I quickly turn it off. I pop the hood and see smoke and bright orange coming from the exhaust manifold and turbine housing. I call Bob, he tells me to loosen the cam angle sensor and rotate a lil counter clock wise, I do, and take it for a test spin, same thing, no power but boost gauge is showing full boost. Then he tells me go the other direction, to put it Half and half between the adjustments, I do and bam prob solved. Power is back, no more dragging feel. And no more over heating. Then on the 40 min drive home the speedometer decides not to work."
Note that last sentence, about the broken speedometer. I suspect his VSS (vehicle speed sensor) is causing the ECU to retard his timing because it is saying "0 MPH" all the time. I couldn't find anything in the forums/FAQs relating VSS to timing. The service and technical manuals say the ECU uses VSS for ignition timing but doesn't say how. It's possible Bob just set the base timing incorrectly (forgot to ground the timing terminal?) but I doubt it because Bob is a long-time well-established DSMer himself.
So my questions are:
1. Am I on the right/wrong track about the VSS?
2. Other ideas besides base timing?
3. My friend wants to drive this thing 4000 miles round-trip in a few days. How nuts is he to try it without nailing this down first? (I say 9/10.)
Thanks in advance for any thoughts/help.
His description of the symptoms:
"Bob sets timing to 5 degrees. Later I leave, car feels as if it were dragging, like boost was being produced but wasn't going anywhere. After 10 mins I find myself unable to accelerate, pulling to the side of the Road using the car's momentum. It starts to overheat and I quickly turn it off. I pop the hood and see smoke and bright orange coming from the exhaust manifold and turbine housing. I call Bob, he tells me to loosen the cam angle sensor and rotate a lil counter clock wise, I do, and take it for a test spin, same thing, no power but boost gauge is showing full boost. Then he tells me go the other direction, to put it Half and half between the adjustments, I do and bam prob solved. Power is back, no more dragging feel. And no more over heating. Then on the 40 min drive home the speedometer decides not to work."
Note that last sentence, about the broken speedometer. I suspect his VSS (vehicle speed sensor) is causing the ECU to retard his timing because it is saying "0 MPH" all the time. I couldn't find anything in the forums/FAQs relating VSS to timing. The service and technical manuals say the ECU uses VSS for ignition timing but doesn't say how. It's possible Bob just set the base timing incorrectly (forgot to ground the timing terminal?) but I doubt it because Bob is a long-time well-established DSMer himself.
So my questions are:
1. Am I on the right/wrong track about the VSS?
2. Other ideas besides base timing?
3. My friend wants to drive this thing 4000 miles round-trip in a few days. How nuts is he to try it without nailing this down first? (I say 9/10.)
Thanks in advance for any thoughts/help.
