Will not start, codes 16705 and 17521

Welcome to 2carPros.

Are you getting fuel and spark to the engine? A lean code can often times correlate with a vacuum leak or low fuel pressure.

Take a look through this link:

https://www.2carpros.com/articles/car-cranks-but-wont-start

Next, check and confirm spark and fuel to the engine. Here are a couple links showing how it is done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-test-an-ignition-system

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Here are the directions specific to checking pressure on your vehicle. You will need a scanner to do this and few other things. The attached pics correlate with the directions.

WITH GENERIC SCAN TOOL
Fuel Pressure Regulator And Residual Pressure, Checking

Function
The fuel pressure regulator controls the fuel pressure as a function of the Manifold Absolute Pressure (MAP).

The specified value for this test is dependent on the working pressure of the Fuel Pump (FP). This is about 3.0 bar positive pressure

Recommended special tools and equipment

pic 1

- V.A.G 1318 pressure gauge
- VAG1318/10 adapter
- VAG1318/11 adapter
- VAG1318/16 hose adapter
- VAS5024 assembly tool for spring-type clamps

Test requirements
- Parking brake must be engaged or else daylight driving lights will be switched on.
- For vehicles with automatic transmission, selector lever must be in position -P- or -N-.
- Delivery quantity of Fuel Pump (FP) OK, check, Fuel Pump (FP), checking. See: Fuel Pump > Component Tests and General Diagnostics

Test sequence

CAUTION: Fuel system is under pressure. Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.

pic 2

- Disconnect fuel supply line -1- (black) from fuel distributor and catch escaping fuel using a rag.

pic 3

- Connect pressure gauge to adapter (VAG1318/10) at supply hose and to adapter (VAG1318/11) and hose adapter (VAG1318/16) at supply line.
- Open shut-off valve of pressure gauge. The lever points in the direction of flow (arrow).
- Start engine and let run at idle.
- Measure fuel pressure. Specified value: about 3.5 bar positive pressure.

pic 4

- Disconnect vacuum hose -1- from connecting piece -2-. Fuel pressure should rise to about 3.0 bar positive pressure rise.

NOTE: If fuel should escape at the vacuum connection of the pressure regulator, replace fuel pressure regulator, item 1.

- Switch ignition off.
- Now check for proper seal and residual pressure. Observe pressure drop on pressure gauge for this. After 10 minutes at least 2.0 bar positive pressure should still be present.

If residual pressure falls below 2 bar positive pressure:
- Start engine and let run at idle.

pic 5

- Wait until pressure has risen, and then switch off ignition. Simultaneously close shut-off valve of pressure gauge (lever perpendicular to direction of flow -arrow-).
- Observe pressure drop on pressure gauge.

If pressure does not drop:
- Test check-valve of Fuel Pump (FP), Fuel Pump (FP), checking. See: Fuel Pump > Component Tests and General Diagnostics
If pressure does drop again:
- Open stop valve of pressure gauge (lever in direction of flow -arrow-).
- Start engine and let run at idle.
- Wait until pressure has risen, and then switch off ignition. Simultaneously pinch return hose tightly together.

If pressure does not drop:
- Replace fuel pressure regulator, item 1.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. See: Computers and Control Systems > Scan Tool Testing and Procedures > Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. See: Computers and Control Systems > Monitors, Trips, Drive Cycles and Readiness Codes

If pressure does drop again:
- Check whether line connections, O-rings in fuel rail, and fuel injectors are properly sealed.
- Check whether pressure gauge is properly sealed.

NOTE: Before removing pressure gauge, put cleaning rags back around line connection which is to be disconnected.

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. See: Computers and Control Systems > Scan Tool Testing and Procedures > Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. See: Computers and Control Systems > Monitors, Trips, Drive Cycles and Readiness Codes

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Let me know what you find or if you have other questions.

Take care,
Joe

Welcome back:

They should show continuity.

P0321 16705 Ignition/Distributor Engine Speed Input Circuit Range/Performance

With that code, the ignition isn't receiving a signal from the crankshaft position sensor (Engine speed sensor). All wire should have continuity. Is there one that doesn't?

I attached three pictures. The first shows the sensor and wiring to it. The second indicates a splice in the wiring (which could be the issue). And the third shows where the three wires connect (pins) on the ECM.

Take a look to see if there is an issue at the splice and if all wires show continuity between the sensor and ECM.

Let me know what you find.

Joe