Hi everyone I have a white 1988 Allante, that I received from my grandfather who who bought it new in late summer of 1988. I have been working to restore it. Aside from a few parts I am getting stuck on a high oil pressure/RMP problem.
Completed before:
The car was sitting at high rpm (1500) and dying randomly on a test run when warm. I worked on the throttle-position sensor (TPS) and idle-speed-control motor (ISC).
I though i had it right with these settings:
Minimum idle with ISC fully retracted 500 RPM
TPS voltage with ISC retracted 0.475–0.525 V, approximately 0.50 V
TPS voltage at maximum ISC extension 1.225–1.325 V, approximately 1.275 V
Diagnostic throttle angle, ED01 −1° to +1°
Issue:
After adjusting the TPS and idle control, I initially thought the engine was running almost perfectly. However, I now have to press the accelerator slightly to get it started. When it’s cold, it randomly sputters while sitting at idle, with the RPM dropping from around 900 to 400—almost stalling—before recovering. Also, Starting the car the oil pressure is as high as it can go (no light). Putting the car in gear and moving it forward or backward brings the reading down a few notches, and it stays at that lower reading afterward rather than immediately returning to maximum. Diagnostics showed 57.5 PSI at roughly 700–800 RPM, with the engine fairly warmed up.
The lights flicker during the initial idle, and pressing the brake pedal dims the cabin lights. The brake pedal itself doesn’t appear to cause the sputtering. Once the engine warms up, it settles around 800 RPM and runs more steadily.
The engine-control-system warning comes on with my foot off the accelerator. Touching the accelerator very slightly makes it disappear, but it comes back when I release the pedal.
Background:
- Engine: Fuel-injector work, TPS and idle-speed-control (ISC) work, spark plugs and plug wires, exhaust-manifold work, oil-pan/gasket repairs, and oil/filter changes.
- Instrumentation: Four-wire oil-pressure gauge/sender work and fuel-level gauge troubleshooting.
- Cooling: Replaced both fan motors and the fan-control module.
- Fuel system: Removed/drained the tank and worked on the sending unit and wiring.
- Body and mechanisms: Rebuilt the taillights, trunk and convertible-top pull-down mechanisms; worked on weatherstripping, top-storage lid, and rollers.
- Windows and interior: Window motors, window/door controls, and interior cosmetic work.
- Electrical/audio: Troubleshot grounds, Bose audio, power antenna, chimes, and exterior lighting.
Im tearing my hair out because i know i close on this part.