Stalling issues - Code 31 (Camshaft Position Sensor)

[secondchance]

Originally Posted by MuRCieLaGo

I'll test everything related to fire tomorrow. I hope coil packs have an easy access, I don't feel comfortable to pull the plenum yet.

Thank you I appreciate your help!

If scanner is throwing code 31, even though connected, I'm pretty sure it's cam sensor failure.
Unfortunately, coil packs are under the plenum. Pulling the plenum, once you do it a couple of times, is no big deal. Especially with coolant passage plugged I can get in and out in less than an hour. It's a ZR-1 ownership initiation.

[Z51JEFF]

CHECK ENGINE LIGHT, bucking and the present throuble code 31 is what my 91 did when the cam sensor died.

[Paul Workman]

Jerry's Gaskets has cam position sensors for $150. You'll want to get acquainted with Jerry - seems like most of us do, sooner or later - for all things LT5-related. (Click on the link and it should take you right to the page w/ the sensor on it!)

I agree w/ Secondchance: Pulling the plenum is "a right of passage" for a ZR-1 owner. All the crap you see on the outside of other motors is hidden under the plenum on the LT5. And*, after installing plugs in the INJECTOR HOUSING coolant ports leading to the throttlebody, and having a long nose "T" star tool or a 4" (~10 cm) Snap-On star extension and a drill makes pulling the plenum off about a 5-10 minute job - about like pulling a carb. (Oh...and get a set (or two) of the plenum gaskets from Jerry too, while your at it!)

There's nothing scary about the LT5. It is different and requires certain techniques and sealants, etc; different; not intimidating, and actually FUN to work with, if having the right tools and the FSM!

Welcome to the club! You've come to the right site for "all things ZR-1!

Paul

[Dynomite]

Originally Posted by Paul Workman

after installing plugs in the INJECTOR HOUSING coolant ports leading to the throttlebody, and having a long nose "T" star tool or a 4" (~10 cm) Snap-On star extension and a drill makes pulling the plenum off about a 5-10 minute job - about like pulling a carb. (Oh...and get a set (or two) of the plenum gaskets from Jerry too, while your at it!)

Paul

Concur with Paul

Removing Plenum (including the 10 minute Plenum Removal)

Injector Housing TB Coolant Blocking

Jerrys Plenum Gasket

Originally Posted by MuRCieLaGo

I don't feel comfortable to pull the plenum yet.

Just Do It
Get the right tools handy and we will be here as you go.....just post up any questions as someone will answer within a few minutes usually.
If a Torx bolt does not want to move....take it easy and post up as you do not want to strip the heads of any Torx. Same goes with metric bolt. Usually not an issue however except on Injector Housing Coolant Manifold Bolts if you decide to Block TB Coolant.

And.......when you get Plenum Off....there are some simple things to do list including Valley Drain Cleaning, Starter Solenoid Reconditioning, Tightening Crank Case Cover Bolts, Checking Vacuum System for Leaks...........all of which only take a few minutes each.

You can even take a Pressure Washer to the Valley after the coils and starter have been removed.

[MuRCieLaGo]

Originally Posted by secondchance

If scanner is throwing code 31, even though connected, I'm pretty sure it's cam sensor failure.
Unfortunately, coil packs are under the plenum. Pulling the plenum, once you do it a couple of times, is no big deal. Especially with coolant passage plugged I can get in and out in less than an hour. It's a ZR-1 ownership initiation.

Originally Posted by Z51JEFF

CHECK ENGINE LIGHT, bucking and the present throuble code 31 is what my 91 did when the cam sensor died.

I removed the cam sensor and went to test it in a well-known electrical shop where I live. Cam sensor works fine.

Originally Posted by Paul Workman

Jerry's Gaskets has cam position sensors for $150. You'll want to get acquainted with Jerry - seems like most of us do, sooner or later - for all things LT5-related. (Click on the link and it should take you right to the page w/ the sensor on it!)

I agree w/ Secondchance: Pulling the plenum is "a right of passage" for a ZR-1 owner. All the crap you see on the outside of other motors is hidden under the plenum on the LT5. And*, after installing plugs in the INJECTOR HOUSING coolant ports leading to the throttlebody, and having a long nose "T" star tool or a 4" (~10 cm) Snap-On star extension and a drill makes pulling the plenum off about a 5-10 minute job - about like pulling a carb. (Oh...and get a set (or two) of the plenum gaskets from Jerry too, while your at it!)

There's nothing scary about the LT5. It is different and requires certain techniques and sealants, etc; different; not intimidating, and actually FUN to work with, if having the right tools and the FSM!

Welcome to the club! You've come to the right site for "all things ZR-1!

Paul

Alright, I'll remove the plenum then. I thought it was a harder job. Unfortunately I don't have the FSM. Is there a digital copy of a 1991 somewhere? Thanks for the welcome words, I really appreciate this forum.

Originally Posted by Dynomite

Concur with Paul

Removing Plenum (including the 10 minute Plenum Removal)

Injector Housing TB Coolant Blocking

Jerrys Plenum Gasket



Just Do It
Get the right tools handy and we will be here as you go.....just post up any questions as someone will answer within a few minutes usually.
If a Torx bolt does not want to move....take it easy and post up as you do not want to strip the heads of any Torx. Same goes with metric bolt. Usually not an issue however except on Injector Housing Coolant Manifold Bolts if you decide to Block TB Coolant.

And.......when you get Plenum Off....there are some simple things to do list including Valley Drain Cleaning, Starter Solenoid Reconditioning, Tightening Crank Case Cover Bolts, Checking Vacuum System for Leaks...........all of which only take a few minutes each.

You can even take a Pressure Washer to the Valley after the coils and starter have been removed.

I'll remove the plenum this afternoon. However, I need to search for how to test the injectors (that's the next thing I need to test I guess). Haven't found some good, easy explanations yet.

Thanks Dynomite for the complete answer!

[MuRCieLaGo]

Oh and quick updates...

-SES light doesn't come on if I put my key on for 5 seconds before starting the engine.

-Runs perfect when cold.

-WOT at Full Power is perfect at all time (I don't think the LT5 is supposed to be faster).

[Dynomite]

Originally Posted by MuRCieLaGo

I'll remove the plenum this afternoon. However, I need to search for how to test the injectors (that's the next thing I need to test I guess). Haven't found some good, easy explanations yet.

Thanks Dynomite for the complete answer!

INJECTORS
Changing Fuel Injectors TIPS
Bad injector/burnt valves TIPS
Secondary Injector Drivers TIPS
Checking Injector Resistance with Plenum in Place TIPS
RC Injectors
Fuel injector testing electrical
Fuel injector testing pressurized
Bad injectors

[MuRCieLaGo]

Originally Posted by Dynomite

INJECTORS
Changing Fuel Injectors TIPS
Bad injector/burnt valves TIPS
Secondary Injector Drivers TIPS
Checking Injector Resistance with Plenum in Place TIPS
RC Injectors
Fuel injector testing electrical
Fuel injector testing pressurized
Bad injectors

Yes thanks, your sticky threads are a bible!

Just need to understand the diagram now.



FSM is on its way.