1994 S10 4.3 5 speed z vin / Would anyone know where the variable throttle control relay is located?
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There a bit of confused terminology in the owners manual. And it's mistaken about what fuse it's on.
The Variable Tuning Control relay, which operates the Variable Tuning Valve Solenoid to open or close the Variable Tuning Valve as commanded by the PCM is on the ECM/IGN fuse #10. Not #4 as the Owners manual states. At least that's what the factory service manuals wiring diagram shows.
What is on #4 Gauges that is not mentioned is the Cruise Control. Which I suppose could be also called Variable Throttle Control, which doesn't have a relay.
The Variable Tuning Control relay is either on the left or right sideof the firewall on a bracket. Has 4 wires term A pink/blk 12v term C dkgrn/wht grounded by PCM to close relay and apply volt to VTCS
term D pink/blk 12V Brn/wht 12v when relay is closed. This wire goes to VTCS which is grounded G117 right rear cylinder head.
Ohm checking and voltage checks will verify if relay and solenoid are operable. And no signal from PCM on C would mean either PCM has not received info or is faulty. It's operated by MAP and VSS, so if MAP is not signaling vac change in manifold in relation to TPS and vehicle speed it may not operate. MAP should read 1.5V at idle if it's working right.
Here's what it does;
The intake manifold used on 94-95 4.3L engines with Central Point Injection (CPI) includes a split path. This system is used to improve engine torque and horsepower over a broader RPM range. The PCM uses inputs from the TP sensor and engine RPM to control a intake manifold tuning (rotary solenoid) valve. The rotary solenoid valve is located in middle of intake manifold. During low RPM and high RPM operations, the PCM releases control. Under these conditions, the intake manifold splits the airflow path. During mid-range RPM operation, a rotary solenoid valve operates and the intake manifold forms a single path for airflow.
No wonder they dropped it in 96.
The Variable Tuning Control relay, which operates the Variable Tuning Valve Solenoid to open or close the Variable Tuning Valve as commanded by the PCM is on the ECM/IGN fuse #10. Not #4 as the Owners manual states. At least that's what the factory service manuals wiring diagram shows.
What is on #4 Gauges that is not mentioned is the Cruise Control. Which I suppose could be also called Variable Throttle Control, which doesn't have a relay.
The Variable Tuning Control relay is either on the left or right sideof the firewall on a bracket. Has 4 wires term A pink/blk 12v term C dkgrn/wht grounded by PCM to close relay and apply volt to VTCS
term D pink/blk 12V Brn/wht 12v when relay is closed. This wire goes to VTCS which is grounded G117 right rear cylinder head.
Ohm checking and voltage checks will verify if relay and solenoid are operable. And no signal from PCM on C would mean either PCM has not received info or is faulty. It's operated by MAP and VSS, so if MAP is not signaling vac change in manifold in relation to TPS and vehicle speed it may not operate. MAP should read 1.5V at idle if it's working right.
Here's what it does;
The intake manifold used on 94-95 4.3L engines with Central Point Injection (CPI) includes a split path. This system is used to improve engine torque and horsepower over a broader RPM range. The PCM uses inputs from the TP sensor and engine RPM to control a intake manifold tuning (rotary solenoid) valve. The rotary solenoid valve is located in middle of intake manifold. During low RPM and high RPM operations, the PCM releases control. Under these conditions, the intake manifold splits the airflow path. During mid-range RPM operation, a rotary solenoid valve operates and the intake manifold forms a single path for airflow.
No wonder they dropped it in 96.
Yeah that's a lot of tech stuff that should have been updated years ago.There a bit of confused terminology in the owners manual. And it's mistaken about what fuse it's on.
The Variable Tuning Control relay, which operates the Variable Tuning Valve Solenoid to open or close the Variable Tuning Valve as commanded by the PCM is on the ECM/IGN fuse #10. Not #4 as the Owners manual states. At least that's what the factory service manuals wiring diagram shows.
What is on #4 Gauges that is not mentioned is the Cruise Control. Which I suppose could be also called Variable Throttle Control, which doesn't have a relay.
The Variable Tuning Control relay is either on the left or right sideof the firewall on a bracket. Has 4 wires term A pink/blk 12v term C dkgrn/wht grounded by PCM to close relay and apply volt to VTCS
term D pink/blk 12V Brn/wht 12v when relay is closed. This wire goes to VTCS which is grounded G117 right rear cylinder head.
Ohm checking and voltage checks will verify if relay and solenoid are operable. And no signal from PCM on C would mean either PCM has not received info or is faulty. It's operated by MAP and VSS, so if MAP is not signaling vac change in manifold in relation to TPS and vehicle speed it may not operate. MAP should read 1.5V at idle if it's working right.
Here's what it does;
The intake manifold used on 94-95 4.3L engines with Central Point Injection (CPI) includes a split path. This system is used to improve engine torque and horsepower over a broader RPM range. The PCM uses inputs from the TP sensor and engine RPM to control a intake manifold tuning (rotary solenoid) valve. The rotary solenoid valve is located in middle of intake manifold. During low RPM and high RPM operations, the PCM releases control. Under these conditions, the intake manifold splits the airflow path. During mid-range RPM operation, a rotary solenoid valve operates and the intake manifold forms a single path for airflow.
No wonder they dropped it in 96.
Thank you for the info definitely helps
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I just realized your title says it's a vin Z. They don't have a VTC. It's in the runners on the CPI, but on TBI there are no runners.
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If you see a CPI intake you'll know what they are. That thing in the middle of the runners is the Variable Tuning Solenoid. It sits on top of the valve.
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Wow that is definitely different
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