Dear Friends,
I have a 2003 Jetta Wagon with 215,000 miles. Recent head work since camshaft had some damage. New belt, 11mm pump I had, stock turbo, new timing belt, etc.
The engine purs like a charm, but have had some hiccups that I can´t figure out.
The car seems to have higher torque only at higher rpms, furthermore it almost seems to have bursts of torque, first at 3k and other at 4k. When followed with a log on group 10, these bursts of torque seem to coincide with mini peaks of the MAF reading.
Things to keep in mind:
- Timing is on the spot.
- Cat was partially blocked so I straight piped it and seemed to slightly improve my problem.
- During work, turbo stop screw was handled for some reason. Both stop screw and actuator rod had been adjusted with VCDS and required boost vs. delivered follows very satisfactoraly through a full power run. Vanes are free, actuator is fairly new and runs freely. N75 works fine with VCDS test cycle.
- I was suspicious of my MAF sensor so bought a new one to no avail (hate spending on parts that don´t solve the issue).
- I installed a very stout lift pump I had lying around after having air leaks that gave me hard starting after long periods of shut down with a previous IP. The IP fuel inlet has a by pass to the return line, so the lift pump pressure does not affect in any way the inner pressure of the IP.
Has anybody else had this issue? Am I missing something here? Thanks in advance for all your help!
I have a 2003 Jetta Wagon with 215,000 miles. Recent head work since camshaft had some damage. New belt, 11mm pump I had, stock turbo, new timing belt, etc.
The engine purs like a charm, but have had some hiccups that I can´t figure out.
The car seems to have higher torque only at higher rpms, furthermore it almost seems to have bursts of torque, first at 3k and other at 4k. When followed with a log on group 10, these bursts of torque seem to coincide with mini peaks of the MAF reading.
Things to keep in mind:
- Timing is on the spot.
- Cat was partially blocked so I straight piped it and seemed to slightly improve my problem.
- During work, turbo stop screw was handled for some reason. Both stop screw and actuator rod had been adjusted with VCDS and required boost vs. delivered follows very satisfactoraly through a full power run. Vanes are free, actuator is fairly new and runs freely. N75 works fine with VCDS test cycle.
- I was suspicious of my MAF sensor so bought a new one to no avail (hate spending on parts that don´t solve the issue).
- I installed a very stout lift pump I had lying around after having air leaks that gave me hard starting after long periods of shut down with a previous IP. The IP fuel inlet has a by pass to the return line, so the lift pump pressure does not affect in any way the inner pressure of the IP.
Has anybody else had this issue? Am I missing something here? Thanks in advance for all your help!