I went out for a ride last night and got on the gas twice, the first time the turbo spooled up fine, then at about 7 psi it shuttered hard once or twice, after that it went straight up to 11 psi or so. I had a shimmed turbo so that seemed normal. It had no boost cut at the higher levels of boost. But did have a CEL. I got home and diagnosed, code 34 as I posted yesterday.
Second ride last night, pulled EFI fuse for a minute and plugged it back in. Rode for a bit to warm the car up and did a pull. This time, no shutter but hit boost cut at higher boost. No CEL or codes. I figured it was just boost cut.
Today, I pulled the shims off of the wastegate actuator and went for a ride. Same old thing, let the car warm up then do a pull. Tonight shutters from 7 psi and wastegate opens fine but with the car shaking hard. This happens in first and second gear but when the car gets to third and about 80-100 which is going by very fast BTW the car is running perfectly, look at the boost gauge and it is pegged out around 11 psi or so, no shims just on its own. I know the wastegate opens because I revved the car standing beside it today and watched it open, about 3/4 of an inch of travel in the actuator rod so I am assuming it is opening all the way. The weird thing was even though it was boosting very high at the higher speeds/gears it was running perfectly smooth and pulling WAY harder than it was at lower speeds.
I am thinking it could be a sticking wastegate actuator but I watch it open when I stand beside the car and rev it with my hand.
I am also thinking it could be boost cut but it is coming in way to soon at almost stock boost pressures.
It could also be ignition related, the sparkplugs that are in the car are old according to the guy I bought my car from(Chris, gixxer750) so I am thinking that could be part of the problem.
It might also be worthy of note that the car stays revved up when it is in park after driving. I am thinking that might be some stickage in the linkage but I have no idea.
I also have a idea that it might be a Throttle Pos. Sensor going out, but the car is not throwing a code for anything at all.
Car info;
89 Supra Turbo
Divorced down pipe 3" all the way back w/o catalytic converters
mild port and polish rebuilt head
thick hks headgasket
6m crank and rebuilt bottom end
cone air filter conversion
Second ride last night, pulled EFI fuse for a minute and plugged it back in. Rode for a bit to warm the car up and did a pull. This time, no shutter but hit boost cut at higher boost. No CEL or codes. I figured it was just boost cut.
Today, I pulled the shims off of the wastegate actuator and went for a ride. Same old thing, let the car warm up then do a pull. Tonight shutters from 7 psi and wastegate opens fine but with the car shaking hard. This happens in first and second gear but when the car gets to third and about 80-100 which is going by very fast BTW the car is running perfectly, look at the boost gauge and it is pegged out around 11 psi or so, no shims just on its own. I know the wastegate opens because I revved the car standing beside it today and watched it open, about 3/4 of an inch of travel in the actuator rod so I am assuming it is opening all the way. The weird thing was even though it was boosting very high at the higher speeds/gears it was running perfectly smooth and pulling WAY harder than it was at lower speeds.
I am thinking it could be a sticking wastegate actuator but I watch it open when I stand beside the car and rev it with my hand.
I am also thinking it could be boost cut but it is coming in way to soon at almost stock boost pressures.
It could also be ignition related, the sparkplugs that are in the car are old according to the guy I bought my car from(Chris, gixxer750) so I am thinking that could be part of the problem.
It might also be worthy of note that the car stays revved up when it is in park after driving. I am thinking that might be some stickage in the linkage but I have no idea.
I also have a idea that it might be a Throttle Pos. Sensor going out, but the car is not throwing a code for anything at all.
Car info;
89 Supra Turbo
Divorced down pipe 3" all the way back w/o catalytic converters
mild port and polish rebuilt head
thick hks headgasket
6m crank and rebuilt bottom end
cone air filter conversion