Mike98GSX
Probationary Member
- 23
- 0
- Dec 18, 2009
-
Holland,
Michigan
Recently, I was coming home from work one night and noticed the car was acting strangely. As I pulled in my driveway to park the car in the garage, it just shut down on me. I tried everything to figure out why it died and why it wouldn't start again. It wasn't until I pulled the valve cover off to discover that all the rocker arms on the intake side where sitting down in the head, presumably jumped timing and bent all the intake valves.
Well, I was correct.
I replaced and fixed what needed to be done to get my car running again and finally it's in a decent running condition, besides two things.
A. The car will NOT build boost. At idle my boost gauge fluctuates between 0.6 and 0.4. Full throttle it fluctuates between 0.6 and 0.4. And cruising it fluctuates between 0.6 and 0.4. When I pulled the head off the car (to install a new head, new valves, springs, retainers etc...) I unbolted the turbo from the manifold and did not touch the turbo what so ever. So I wouldn't understand how something could be wrong with it. It worked amazing before I bent the valves, so I could not begin to understand what the deal is now. I've set a minor tune to the car since getting it to move under it's own power (Setting deadtime, adjusting slight timing to eliminate knock and other misc. things). I've checked over almost everything. All my piping in the car is bolted down with T-Bolt clamps and all are securely fastened, no leaks. I have not "physically" checked the turbo, but it is a ball bearing turbo and when you shut the car down, you can hear it freely spinning until it comes to a stop. I've also checked my vacuum lines to make sure they are ok, as well as my manual boost controller and made sure that it wasn't turned down all the way. No cracks or damages to the vacuum lines and the boost controller is set to about the same way it was before the bent valves incident. The only thing that I have yet to check is if the internal wastegate on the turbo is somehow "stuck" open.
B. The car will NOT go past 4,000-4,500 RPM's. It's almost like hitting a brick wall. Once I reach about 4,000 RPM's knock rises to 12+ degrees and retards the timing to prevent detonation. I've pulled a few degrees of timing and backed off some fuel delivery in those RPM ranges and there was only a slight difference.
The car does have adjustable cam gears. I do believe they were tampered with while getting the engine back into time. Reason for doing so: This is a 4G64 2.4 block with a 2G cylinder head, the block height is different on a 4G64 then what it is on a 4G63. So setting mechanical timing is a tad different. However, I do believe that the mechanical timing is correct, because how else would the car even be running and driving if it wasn't?
I'm honestly stumped by this one and I really don't know what's going on with the engine/turbo. Any insight or suggestions will be taken into consideration and thankful for.
Well, I was correct.
I replaced and fixed what needed to be done to get my car running again and finally it's in a decent running condition, besides two things.
A. The car will NOT build boost. At idle my boost gauge fluctuates between 0.6 and 0.4. Full throttle it fluctuates between 0.6 and 0.4. And cruising it fluctuates between 0.6 and 0.4. When I pulled the head off the car (to install a new head, new valves, springs, retainers etc...) I unbolted the turbo from the manifold and did not touch the turbo what so ever. So I wouldn't understand how something could be wrong with it. It worked amazing before I bent the valves, so I could not begin to understand what the deal is now. I've set a minor tune to the car since getting it to move under it's own power (Setting deadtime, adjusting slight timing to eliminate knock and other misc. things). I've checked over almost everything. All my piping in the car is bolted down with T-Bolt clamps and all are securely fastened, no leaks. I have not "physically" checked the turbo, but it is a ball bearing turbo and when you shut the car down, you can hear it freely spinning until it comes to a stop. I've also checked my vacuum lines to make sure they are ok, as well as my manual boost controller and made sure that it wasn't turned down all the way. No cracks or damages to the vacuum lines and the boost controller is set to about the same way it was before the bent valves incident. The only thing that I have yet to check is if the internal wastegate on the turbo is somehow "stuck" open.
B. The car will NOT go past 4,000-4,500 RPM's. It's almost like hitting a brick wall. Once I reach about 4,000 RPM's knock rises to 12+ degrees and retards the timing to prevent detonation. I've pulled a few degrees of timing and backed off some fuel delivery in those RPM ranges and there was only a slight difference.
The car does have adjustable cam gears. I do believe they were tampered with while getting the engine back into time. Reason for doing so: This is a 4G64 2.4 block with a 2G cylinder head, the block height is different on a 4G64 then what it is on a 4G63. So setting mechanical timing is a tad different. However, I do believe that the mechanical timing is correct, because how else would the car even be running and driving if it wasn't?
I'm honestly stumped by this one and I really don't know what's going on with the engine/turbo. Any insight or suggestions will be taken into consideration and thankful for.
