SIIaCanuck
New Member
For those who read my 'strange idle' thread, I'm looking for follow up advice. The original problem was 122/124 codes for an old TPS with a dead spot, which I replaced. RPM was hanging up at 1600rpm after along run, slowly dropping back to idle after 20-30 seconds or so sitting at a light.
After replacing the TPS, I drove it for a couple of weeks and started getting a hunting idle. Then, on a hot day, after a long run home, she quit on me. Classic signs of fuel starvation (or vapour lock). Once cooled off, she started and ran like normal. Codes pulled were 121 (TPS voltage out of normal range), 172 (RHS O2 sensor lean) and 556 (fuel pump primary circuit fault). Fuel pressure was down at about 28-30psi at idle.
I've put in a new 170lph pump, fuel filter, adjustable fuel regulator, Blaster 2 coil & new cap/rotor. I set up the fuel pressure at idle at 36psi (vacuum off). Timing is still at 10 degrees.
The hunting idle is gone and the car seems to run and accelerate more smoothly. I cleared all the codes and drove the car to church this morning (20 miles total), with a couple of hammer down accelerations and a bit of time on cruise control.
Pulled codes to check and got a 121 (TPS out of normal range) and a 172 (RH O2 sensor lean).
121 - I'm thinking that the new TPS is giving a strange voltage. It's non-adjustable and the computer should set the idle volts at start and it seems to respond to throttle normally. I'll call the shop about the TPS to get their thoughts and maybe plan to swap out the TPS if there's a chance it's got a fault from the factory.
172 - Injectors, O2 sensor, fuel pressure low (should I bump it up to closer to stock spec? 39psi?)? It's only the RHS so it seems unlikely that it's an intake air leak or MAP problem.
Thoughts or comments? Other things to check?
After replacing the TPS, I drove it for a couple of weeks and started getting a hunting idle. Then, on a hot day, after a long run home, she quit on me. Classic signs of fuel starvation (or vapour lock). Once cooled off, she started and ran like normal. Codes pulled were 121 (TPS voltage out of normal range), 172 (RHS O2 sensor lean) and 556 (fuel pump primary circuit fault). Fuel pressure was down at about 28-30psi at idle.
I've put in a new 170lph pump, fuel filter, adjustable fuel regulator, Blaster 2 coil & new cap/rotor. I set up the fuel pressure at idle at 36psi (vacuum off). Timing is still at 10 degrees.
The hunting idle is gone and the car seems to run and accelerate more smoothly. I cleared all the codes and drove the car to church this morning (20 miles total), with a couple of hammer down accelerations and a bit of time on cruise control.
Pulled codes to check and got a 121 (TPS out of normal range) and a 172 (RH O2 sensor lean).
121 - I'm thinking that the new TPS is giving a strange voltage. It's non-adjustable and the computer should set the idle volts at start and it seems to respond to throttle normally. I'll call the shop about the TPS to get their thoughts and maybe plan to swap out the TPS if there's a chance it's got a fault from the factory.
172 - Injectors, O2 sensor, fuel pressure low (should I bump it up to closer to stock spec? 39psi?)? It's only the RHS so it seems unlikely that it's an intake air leak or MAP problem.
Thoughts or comments? Other things to check?