V1a2s2h4
Active member
Recently changed melted vacuum lines to fix a p0299 cel but still had random limp mode symptoms. Plugged a vaccum gage to the turbo line and at idle the n75 was drawing only 5inHg on the turbo down from the normal 17. I squeezed the line a few times and it rose back to a normal idle value. Would that indicate the n75 i shot?
I've been driving with the vaccum gage connected to the line going down to the turbo to watch the relationship between vac pull and boost. When the limp mode symptoms occur, vaccum will fall down to 5inHg and I'll get a max of 4 psi with the pedal to the floor. What happens next is what puzzles me the most, vac pressure will climb back to 25inhg But when I touch the pedal it flatlines to 0 and I get no boost from turbo.
Sometimes it takes a few restarts to get out of limp mode, but could all this be pointing to the n75?
Any feedback would be greatly appreciated.
*Update 1* stopped at a rest stop after driving 80 miles without any issue, on restart the car is reading 6inhg, down again from the 17 it should be at idle. 2 restarts and it's went back to normal and pulling away from the stop it boosted normally. Cruising at 75 the vac gage was reading a steady 13inhg, about 2 miles later it drops to 5inHg and the CEL for p0299 comes back. Still getting some boost from the turbo but nothing near it's normal.
*Update2* about 20 miles into having low boost the vac gage dropped to 0 as I attempted to pass someone. Now on no boost I shifted to neutral and did a rolling restart. 2 restarts later vac idle returned to normal and car started boosting like normal. System is holding steady vaccum as of now.
I've been driving with the vaccum gage connected to the line going down to the turbo to watch the relationship between vac pull and boost. When the limp mode symptoms occur, vaccum will fall down to 5inHg and I'll get a max of 4 psi with the pedal to the floor. What happens next is what puzzles me the most, vac pressure will climb back to 25inhg But when I touch the pedal it flatlines to 0 and I get no boost from turbo.
Sometimes it takes a few restarts to get out of limp mode, but could all this be pointing to the n75?
Any feedback would be greatly appreciated.
*Update 1* stopped at a rest stop after driving 80 miles without any issue, on restart the car is reading 6inhg, down again from the 17 it should be at idle. 2 restarts and it's went back to normal and pulling away from the stop it boosted normally. Cruising at 75 the vac gage was reading a steady 13inhg, about 2 miles later it drops to 5inHg and the CEL for p0299 comes back. Still getting some boost from the turbo but nothing near it's normal.
*Update2* about 20 miles into having low boost the vac gage dropped to 0 as I attempted to pass someone. Now on no boost I shifted to neutral and did a rolling restart. 2 restarts later vac idle returned to normal and car started boosting like normal. System is holding steady vaccum as of now.
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