savanna13
04-11-2007, 02:08 PM
First off: 1G GS300 Aristo GTE/Auto with single 70 trim T4 and Tial 38 (10LB spring, Greddy Profec B to hold boost at 14 LBS), running stock 440's and an SAFC with a full 3 inch exhuast.
One day 2 weeks ago, I was driving my car to work and it started hesitating and acting strange, idling erratically and dragging no/light boost part throttle shifts out for wayyyyyyyy longer than normal. I immediately pulled the plugs to find that they were covered in oil, which was not much of a surprise because of my leaking valve cover gasket. I changed the valve cover gasket, the plugs, and did a compression test (180 across the board). After I broke all of the coilpack connectors and had to order new ones from Toyota, I plugged everything back in and took it for a spin, only to find immediate gayness.
Like I said, it idles like it only has 5 cylinders or a nasty cam, but only sometimes.... when the vacuum drops from 20+ lbs at 650RPM idle to about 12-15 lbs. It also causes my Air/Fuel ratio to go nuts... crazy lean or rich, depending on what seems to be its mood. OK, so it has a vacuum leak, right? The only leak I could find was my intake manifold gasket (using starter fluid while letting the car idle to listen for surge). There is just one hangup: Ever since it started doing this, my car will not hold boost below 14lbs, even with my boost controller turned off (running off of the 10LB spring alone). It will blow to 18-25 LBS IMMEDIATELY, provided the car is anywhere above 3k RPM. WTF?! Could an intake manifold gasket leak cause extreme boost spike?
HELP ME!
I plan on replacing the gasket and upgrading the injectors to Supra 550's (with twin DSM resistor boxes) when I pull the manifold.
Can anyone confirm or relate to this? Thanks in advance!
One day 2 weeks ago, I was driving my car to work and it started hesitating and acting strange, idling erratically and dragging no/light boost part throttle shifts out for wayyyyyyyy longer than normal. I immediately pulled the plugs to find that they were covered in oil, which was not much of a surprise because of my leaking valve cover gasket. I changed the valve cover gasket, the plugs, and did a compression test (180 across the board). After I broke all of the coilpack connectors and had to order new ones from Toyota, I plugged everything back in and took it for a spin, only to find immediate gayness.
Like I said, it idles like it only has 5 cylinders or a nasty cam, but only sometimes.... when the vacuum drops from 20+ lbs at 650RPM idle to about 12-15 lbs. It also causes my Air/Fuel ratio to go nuts... crazy lean or rich, depending on what seems to be its mood. OK, so it has a vacuum leak, right? The only leak I could find was my intake manifold gasket (using starter fluid while letting the car idle to listen for surge). There is just one hangup: Ever since it started doing this, my car will not hold boost below 14lbs, even with my boost controller turned off (running off of the 10LB spring alone). It will blow to 18-25 LBS IMMEDIATELY, provided the car is anywhere above 3k RPM. WTF?! Could an intake manifold gasket leak cause extreme boost spike?
HELP ME!
I plan on replacing the gasket and upgrading the injectors to Supra 550's (with twin DSM resistor boxes) when I pull the manifold.
Can anyone confirm or relate to this? Thanks in advance!