Help...Timing issue

[Reebuck1]

I recently installed a L/N IMS bearing. Used the install kit to do work. Locked Bank1 exhaust cam at TDC while doing the work.......but it turned out to be

TDC for Bank 2. When I was (clock wise) rotating the crank it obviously stopped moving. I realized the mistake and backed the crank up (counter clock wise) to the proper TDC for Bank 1. I then installed the motor and trans in car. Car started but would die when moving toward idle speed. When I got the car up to operating temp. it would hold idle but only at about 400 or 500 with an uneven idle. At 2000 RPM or 3000 rpm it runs just fine.

I am getting an OBD error code of # P1531- Cam Shaft Adjustment/ Bank1...short to short.

Can anyone suggest what I should do next?

Thanks in advance, Bob

[JFP in PA]

I recently installed a L/N IMS bearing. Used the install kit to do work. Locked Bank1 exhaust cam at TDC while doing the work.......but it turned out to be

TDC for Bank 2. When I was (clock wise) rotating the crank it obviously stopped moving. I realized the mistake and backed the crank up (counter clock wise) to the proper TDC for Bank 1. I then installed the motor and trans in car. Car started but would die when moving toward idle speed. When I got the car up to operating temp. it would hold idle but only at about 400 or 500 with an uneven idle. At 2000 RPM or 3000 rpm it runs just fine.

I am getting an OBD error code of # P1531- Cam Shaft Adjustment/ Bank1...short to short.

Can anyone suggest what I should do next?

Thanks in advance, Bob

First of all, for future reference, never rotate one of these engines counter clockwise, doing so can put this interference motor in a position it does not want to be and end up causing mechanical damage.

Code P1531 is for no change in the cam angle on bank #1; as you have had the engine out of the car, I'd start by looking at the wiring and connectors for the VarioCam system and cam position sensor on bank #1, it may simply be disconnected.

[Reebuck1]

Checked Bank 1 solenoid with a small 9v battery and could hear it clicking. Plugged it back into harness checked sensor and it looks plugged in. Engine still in car so I pulled green plugs to try and check timing. Hear are some pictures that can provide more info.

This started it all. Original IMS

Car has an Auto trans. so I am guessing this bearing cover is seeing some slight leakage and not clutch dust.

This is the original bearing I removed.




This shows engine at Bank 1 TDC with crank lock in.


Engine is presently in car so some of the pictures can not be taken "head on". But bank1 and Bank2 exhaust cam slots line up perfectly with the split between cam cover and main case. They seem properly positioned to me. I've been wrong before!

Bank 1 green plug removed shows Bank1 Exhaust cam position.



This picture show bank1 intake cam notch facing out board (away from the motor)
red pen pointing to notch. Note that the notch is slightly pointing UP from a dead level position. Is that a correct position?


The error code from the car at start up was P-1531 and referenced Bank1. But to me everything in Bank1 looked close. What is the general thinking?

Back to bank 1. This afternoon I checked the bank 1 solenoid to ensure it was functioning. I disconnected the solenoid from the harness and used a small 9V. battery to see if I could hear it click. I clicked it several times and it worked every time. I am not sure it would tell me if it were stuck but I could hear slight movement. I did not check wiring on the other side of the plug back to the main wiring harness. This shows picture shows the solenoid. It appeared to be slightly leaking before I cleaned it.



Moving to Bank 2. This is the exhaust cam slot showing vertical position with the crank still locked in the same position as when I checked bank 1. It was difficult to take pictures on this side but the exhaust slot matched the case split.



This picture shows the intake cam slot on Bank 2 pointing out board (away from the engine). Again difficult to see but appears ok to my untrained eye.


Because of angles pictures are not great but the two exhaust cam slots line up with the case split perfectly. The Bank 1 intake cam slot is pointing up slightly from dead level Bank 2

is dead level (horizontal) and both are pointing out board with motor at TDC bank 1(exhaust cam).

Any suggestions?

[JFP in PA]

Checked Bank 1 solenoid with a small 9v battery and could hear it clicking. Plugged it back into harness checked sensor and it looks plugged in. Engine still in car so I pulled green plugs to try and check timing. Hear are some pictures that can provide more info.

This started it all. Original IMS

Car has an Auto trans. so I am guessing this bearing cover is seeing some slight leakage and not clutch dust.

This is the original bearing I removed.

This shows engine at Bank 1 TDC with crank lock in.

Engine is presently in car so some of the pictures can not be taken "head on". But bank1 and Bank2 exhaust cam slots line up perfectly with the split between cam cover and main case. They seem properly positioned to me. I've been wrong before!

Bank 1 green plug removed shows Bank1 Exhaust cam position.

This picture show bank1 intake cam notch facing out board (away from the motor)

red pen pointing to notch. Note that the notch is slightly pointing UP from a dead level position. Is that a correct position?

The error code from the car at start up was P-1531 and referenced Bank1. But to me everything in Bank1 looked close. What is the general thinking?

Back to bank 1. This afternoon I checked the bank 1 solenoid to ensure it was functioning. I disconnected the solenoid from the harness and used a small 9V. battery to see if I could hear it click. I clicked it several times and it worked every time. I am not sure it would tell me if it were stuck but I could hear slight movement. I did not check wiring on the other side of the plug back to the main wiring harness. This shows picture shows the solenoid. It appeared to be slightly leaking before I cleaned it.

Moving to Bank 2. This is the exhaust cam slot showing vertical position with the crank still locked in the same position as when I checked bank 1. It was difficult to take pictures on this side but the exhaust slot matched the case split.

This picture shows the intake cam slot on Bank 2 pointing out board (away from the engine). Again difficult to see but appears ok to my untrained eye.

Because of angles pictures are not great but the two exhaust cam slots line up with the case split perfectly. The Bank 1 intake cam slot is pointing up slightly from dead level Bank 2

is dead level (horizontal) and both are pointing out board with motor at TDC bank 1(exhaust cam).

Any suggestions?

Let's start with the basics: Year and model of the car? I know you list an early Boxster in your profile, is that the car?

In any case, something concerns me; when you did the IMS swap, how did you retain the cam positions? In your photos, you show the cam slots as being off to one side:

When the engine is at TDC, the slot in the cam should line up with the parting line in the cam covers:

Quite often, when first setting the TDC position, the cam slots do not seem to line up, but what is happening is that the engine is not really at TDC and needs to be rotated clockwise only until the cams do line up and the locking tools cam be inserted; at times, you have to rotate the engine over a couple times to achieve this configuration:

[Reebuck1]

Here is what I have and did.

1999 996 C2….five chain 3.4 engine (auto trans). With 70,000 miles

Pulled engine and trans. from car. Separated transmission from engine.

Rotated engine to what I thought was TDC.

Pulled cam plug on Bank 1 exhaust exposing cam slot. Verified vertical position of bank 1 exhaust cam with casing split. Inserted exhaust cam locking device for 5 chain engine. Failed to look at Intake cam slot for alignment.

Pulled plug on Bank2 exhaust cam and verified vertical position of exhaust cam slot with case split.

Removed the chain tensioner for cylinders 1-3 only.


Removed bearing with bearing puller.

Original bearing removed: Checked bearing and could feel no play in shaft. Removed seal and could see little race scalding no ball pitting. When seal was removed oil was found in bearing BUT no grease.

Installed bearing per instruction. Bearing and LN insert tool were kept in freezer over night, went in and seated with minimal tapping by rubber dead blow hammer. Circlip installed and seated. New LN IMS cover and three Torx bolts installed and torqued with Curil_T around bolt heads. Center bolt nut and o-ring were installed and torqued with Curil T around bolt head.

Reinstalled chain tensioner for bank 1

Attempted to rotate engine 360 degrees clock wise to check bank 2. Never got there. Engine would not turn 360 degrees. Realized I must not have been at TDC for bank 1. Rotated engine counter clock wise back to original start position. Now know I should not have done that. Then continued to go counter clock wise for another 360 degrees. Now believed I was at TDC for bank 1. Locked crank and Bank 1 exhaust cam and removed chain tensioner for bank 1. Pushed chain up with finger two times then reinstalled the chain tensioner for bank1.

Rotated engine clock wise for 360 and check Bank 2 exhaust cam slot for alignment. Failed to look at bank 2 intake cam alignment.

Installed torque converter to engine crank. Slid transmission and engine together. Heard pop but assumed it was splines for trans and torque converter aligning. Rotated engine
All seemed well.

Installed engine and trans in car. Started car and idle problem showed up. Checked for vacuum leaks and found and repaired one. Scanned engine and got P-1531 error code.

The exhaust cam slots line up perfectly with the case split. Both intake cams are pointing out board (away from motor). Only the Bank 1 intake cam is not dead level (vertical).

It is only slightly tilted up. The angle of some of my pictures is not great because the motor is now in the car and I can not get a straight shot. Hope this helps.

[JFP in PA]

Do you have access to the Durametric software or a PST II?

[Reebuck1]

No I just have an Innova 3100e OBD2 scanner. What would you want me to look at with the Durametric?

[JFP in PA]

No I just have an Innova 3100e OBD2 scanner. What would you want me to look at with the Durametric?

I'd like to see the cams, and particular the one throwing the code, checked for cam deviation angle. The deviation angle is the position of the cam relative to the crankshaft, and normally sit in the +/- 6 degree range at idle, then jump to around 25 degrees when the VarioCam kicks in; the deviation angle will tell if the cam is out of time or not. The Durametric can also activate the VarioCam system, one bank at a time, allowing you to see if it is functioning correctly. Here's an example from an early Boxster:

[Reebuck1]

If the idle in my 73 911S (2.8) were acting as this is ( assumes I am at operating temp) I would turn the distributer a few degrees to advance the spark. Anyway that's what it feel like to me. When I move the RPM range up to 2000 or 3000 RPM it hold rock steady. My OBD also through a P-0123 code but I checked the throttle positioner plug (both sides) with my Ohms meter and it was working fine. only the P1531 code showed up after that.

[JFP in PA]

If the idle in my 73 911S (2.8) were acting as this is ( assumes I am at operating temp) I would turn the distributer a few degrees to advance the spark. Anyway that's what it feel like to me. When I move the RPM range up to 2000 or 3000 RPM it hold rock steady. My OBD also through a P-0123 code but I checked the throttle positioner plug (both sides) with my Ohms meter and it was working fine. only the P1531 code showed up after that.

The car is acting as though the cam timing is off, or that the DME at least thinks it is, which pretty much amounts to the same thing with the exception that actual mechanical deviation can lead to physical engine damage.

You need to get the car hooked up to either the Durametric system, or one of Porsche's systems (PST II or PIWIS) and collect some cam angle data to determine where you are; I know of no other aftermarket diagnostic tool that can be counted on to dependably generate this data.

[Reebuck1]

_{OK, I'll try and find one. Thank you for all your help !!}

[binger]

http://www.durametric.com/buyus.aspx

[Reebuck1]

Ok finally got the Durametric ordered and will get it next week. Once received I'll run the tests and post the results. Thanks all for your help.

[Reebuck1]

Ok, JFP I am back after I purchased a Durametric and was able to run the stats you requested in #8 above. I have not yet figured how to print the whole page like you did because my lap top runs on Micosoft 8. how ever here is the info you asked for:

Camshaft 1 position deviation........ -2.0 Engine Module ME 7.2

Camshaft 2 position deviation......... 3.0 Engine Module M 5.2.2

You Durametric version show soft wear version # 6.0.3.1

My Durametric version shows soft wear version # 6.3.2.5

When I click on "Engine Module 5.2.2" and then click on "Actual Values" then go to the "Available Actual Value" tab I could find the camshaft deviation boxes to check but I did not see

an Actual Angle for Camshaft box I could check. It appears that is not on my version of the Durametric soft wear.

With my new Durametric I cleared all error codes and let the moror idle at operating temp. for ten minutes and it DID NOT throw any error codes.

Please let me know your thoughts. Or anyone else with a suggestion. Thanks again Reebuck1

[JFP in PA]

Ok, JFP I am back after I purchased a Durametric and was able to run the stats you requested in #8 above. I have not yet figured how to print the whole page like you did because my lap top runs on Micosoft 8. how ever here is the info you asked for:

Camshaft 1 position deviation........ -2.0 Engine Module ME 7.2

Camshaft 2 position deviation......... 3.0 Engine Module M 5.2.2

You Durametric version show soft wear version # 6.0.3.1

My Durametric version shows soft wear version # 6.3.2.5

When I click on "Engine Module 5.2.2" and then click on "Actual Values" then go to the "Available Actual Value" tab I could find the camshaft deviation boxes to check but I did not see

an Actual Angle for Camshaft box I could check. It appears that is not on my version of the Durametric soft wear.

With my new Durametric I cleared all error codes and let the moror idle at operating temp. for ten minutes and it DID NOT throw any error codes.

Please let me know your thoughts. Or anyone else with a suggestion. Thanks again Reebuck1

Actually, what is happening is a little different. First, the screen shot capture I posted was taken when software version 6.0.3.1 was current, 6.3.2.5 is what is current now, so that was just a matter of an intervening software update.

The correct DME for your car is the 5.2.2 (1998-1999 model years) not the 7.2 (2000-2001 model years). There are significant differences between the capabilities of these two versions of the DME, and the earlier version is not as capable by comparison. Selecting the wrong DME in the Durametric system can often lead you astray, so go with what is actually in the car. Your early DME does not have all the display capabilities of the later units, so some "actual values" are not available to look at.

If your cam deviation values are within +/-6 degrees at idle, your cams are in correct timing. If you activated the VarioCam at idle, you should see the cam deviation values jump to show the system trying to move the cam around 25 degrees, and the car will start to idle roughly; that would show that the VarioCam unit is functional. If your cam deviation values are in range, the VarioCam is working, and the Durametric is not seeing the P1531 code return, you should be good to go.

[Reebuck1]

Thank you very much for the reply. I am off to Raby Rebuild school in Va. tomorrow so I'll get back on this next week and let you know results. Thanks, Bob

[JFP in PA]

Thank you very much for the reply. I am off to Raby Rebuild school in Va. tomorrow so I'll get back on this next week and let you know results. Thanks, Bob

Enjoy Jake's class, the man literally "wrote the book" in the M96/97 engine.

[Reebuck1]

JFP, You are absolutely right Jakes class was great. It is well worth the money. However, it is humbling to have to realize HOW MUCH YOU REALLY DO NOT KNOW about these motors !! I'd recommend anyone who has a chance to take Jakes course. .

Still have not figured how to do screen print with Window 8 yet but I loged some Durametric data that could be useful with the .

Using the "ACTUAL VALUE" tab I ran tests on most of the items listed under the actual values heading. They are:

RPM 520 it was running slow and choppy and smelled very lean. Bank 1 sounded like it may have a miss.

Air Mass 18 to 21 jumps back and fourth while running

IATS 27.0

ECTS 37.5

Throttle Plate Position 0 stayed steady

Ignition Timing 15 to 18 jumping between these numbers primarily

Oxygen Sensing 1-3 1.00

Oxygen Sensing 4-6 1.00

Range 2 Cg/ 1-3 FRA 1.10

Range 2 Cg/ 4-6 FRA 1.10

Range 2 Cg/ 1-3 TRA 0.37

Range 2 Cg/ 4-6 TRA 0.37

Camshaft Deviation 1-3 crk -2.0 notice this changed from -3.0 the last time I ran this test

Camshaft Deviation 4-6 crk 2.0

Rough Running Threshold I/s2 13.3 to 13.7 jumps between these numbers while running

Rough Running I/s2 0

Segment (A) 1

Segment (B) 1

02 Sensor Voltage ahead of cat. conv. -0.01

02 Sensor Voltage ahead of c. ba 0.00

Load signal 2.15

Hot Film MAF 1.33

Leam. progress sens. wheel adapt. .0007

HO25 heat. res. ahead of cat. conv. 3.2

From what I can tell I am in spec with the Cams but still can not figure why my Idle is so bad. It starts well and 2000 rpm it runs great but when I let off it bogs down.

If you can help point me in the right direction I think I can fix this issue. Thanks, Bob

[Reebuck1]

JFP, Sorry I forgot to mention fault codes. When I ran the above tests I got the following fault codes.

Bosch Digital Motor Electronics Motronic 5.2.2

P1531:
Camshaft adjustment bank 1

P0130:
O2 sensor ahead of cat. conv. Cylinder (1-3)

P0150:
O2 sensor ahead of cat. conv. Cylinder (4-6)

When I cleared all codes (before I left for school) no further codes or repeats came up. The above codes only showed up after the car had been started and run three times.

I also noticed that when it runs rough the exhaust really stinks as if the mixture is too lean.

Hope this helps.................. thanks

[Ahsai]

Funny I was gonna ask you if those 0.00v O2 sensor readings are constant or just because of the snapshot. I think you should address the O2 faults first because as is your fuel management is in open loop so not sure how valid the TRA and FRA values are. Check the wires and connections of both precat sensors. Also, have you tried cleaning the throttle body and idle stabilizer yet?

Edited March 21, 2014 by Ahsai

[JFP in PA]

JFP, Sorry I forgot to mention fault codes. When I ran the above tests I got the following fault codes.

Bosch Digital Motor Electronics Motronic 5.2.2

P1531:

Camshaft adjustment bank 1

P0130:

O2 sensor ahead of cat. conv. Cylinder (1-3)

P0150:

O2 sensor ahead of cat. conv. Cylinder (4-6)

When I cleared all codes (before I left for school) no further codes or repeats came up. The above codes only showed up after the car had been started and run three times.

I also noticed that when it runs rough the exhaust really stinks as if the mixture is too lean.

Hope this helps.................. thanks

JFP, You are absolutely right Jakes class was great. It is well worth the money. However, it is humbling to have to realize HOW MUCH YOU REALLY DO NOT KNOW about these motors !! I'd recommend anyone who has a chance to take Jakes course. .

Still have not figured how to do screen print with Window 8 yet but I loged some Durametric data that could be useful with the .

Using the "ACTUAL VALUE" tab I ran tests on most of the items listed under the actual values heading. They are:

RPM 520 it was running slow and choppy and smelled very lean. Bank 1 sounded like it may have a miss.

Air Mass 18 to 21 jumps back and fourth while running

IATS 27.0

ECTS 37.5

Throttle Plate Position 0 stayed steady

Ignition Timing 15 to 18 jumping between these numbers primarily

Oxygen Sensing 1-3 1.00

Oxygen Sensing 4-6 1.00

Range 2 Cg/ 1-3 FRA 1.10

Range 2 Cg/ 4-6 FRA 1.10

Range 2 Cg/ 1-3 TRA 0.37

Range 2 Cg/ 4-6 TRA 0.37

Camshaft Deviation 1-3 crk -2.0 notice this changed from -3.0 the last time I ran this test

Camshaft Deviation 4-6 crk 2.0

Rough Running Threshold I/s2 13.3 to 13.7 jumps between these numbers while running

Rough Running I/s2 0

Segment (A) 1

Segment ( B) 1

02 Sensor Voltage ahead of cat. conv. -0.01

02 Sensor Voltage ahead of c. ba 0.00

Load signal 2.15

Hot Film MAF 1.33

Leam. progress sens. wheel adapt. .0007

HO25 heat. res. ahead of cat. conv. 3.2

From what I can tell I am in spec with the Cams but still can not figure why my Idle is so bad. It starts well and 2000 rpm it runs great but when I let off it bogs down.

If you can help point me in the right direction I think I can fix this issue. Thanks, Bob

OK, let's look at the data. Here is what jumps out:

• Your idle speed is low, normal range is 790-800 RPM
• Both TRA values are sitting at their rich threshold values
• Cam deviation values are excellent
• Air mass in within normal range
• One O2 sensor showing no voltage

P1531 - Not seeing the triggering VarioCam actuator on bank 1, but the cam is moving to the active position. Usually a wiring short or defective VarioCam actuator.

P0130 - O2 sensor ahead of TWC on bank 1 either shorted or limited voltage range. Three possible: the sensor itself is bad, a wiring to the sensor issue, DME problem (rare).

P0150 - O2 sensor ahead of TWC on bank 2 either shorted or limited voltage range. Same possible as above.

P0130 and 0150, I would look at the harness connections to make sure they are correct and tight (do not use any cleaners on these connections, it typically leads to instant death for the sensor). With both pre TWC sensors "offline", I am not surprised the engine is having a tough time gaining idle control.

P1531, again, I would start by looking at the harness connectors for the actuator. You can also use the Durametric system to trigger the actuator, which should cause a cam deviation angle change and throw the idle off; it also make a pronounced clicking sound when the actuator solenoid triggers.

[Ahsai]

Just curious, are those really TRA values you quoted and not RKAT? My Durametric only repors RKAT (in %). I wonder why the difference. Thanks.

"Range 2 Cg/ 1-3 TRA 0.37

Range 2 Cg/ 4-6 TRA 0.37"

[JFP in PA]

Just curious, are those really TRA values you quoted and not RKAT? My Durametric only repors RKAT (in %). I wonder why the difference. Thanks.

"Range 2 Cg/ 1-3 TRA 0.37

Range 2 Cg/ 4-6 TRA 0.37"

From the "Ragu principle" , it's in there. TRA (bank 1)and TRA2 (bank 2) are the idle sector system adaptation values, typically around a value of 0.150 or so. These actual values can range from -0.37 (lean threshold) to 0.37 (rich threshold) at idle. He is sitting right at the rich threshold values.

[Ahsai]

Just curious, are those really TRA values you quoted and not RKAT? My Durametric only repors RKAT (in %). I wonder why the difference. Thanks.

"Range 2 Cg/ 1-3 TRA 0.37

Range 2 Cg/ 4-6 TRA 0.37"

From the "Ragu principle" , it's in there. TRA (bank 1)and TRA2 (bank 2) are the idle sector system adaptation values, typically around a value of 0.150 or so. These actual values can range from -0.37 (lean threshold) to 0.37 (rich threshold) at idle. He is sitting right at the rich threshold values.

Thanks for the info, John. Still still why my Durametric only reports RKAT (in %) and not TRA but the OP's one can?

The other question is if TRA and RKAT are strictly equivalent e.g. TRA=0.1 => RKAT=10%

[Reebuck1]

Latest update.

Cleaned MAF just in case.

Checked bank 1 and bank 2 pre cat. wires from the cars harness to O2 sensor connection. When I turn the ignition switch on (did not start motor) I get a full 0.50 V down the harnesses signal wire (from the car). But with the ignition still on I got NO voltage down the two heater wires from the car harness.

Next I pulled the O2 sensor off the car and put a ohm meter on the heater leads of the O2 sensor...I got continuity so I assume the heater element is good.

I then applied heat to the tip of the O2 sensor and hooked up my volt meter to tell if I could detect any voltage change in the sensor....I got NO voltage and no change.

I cleaned the throttle body before I reinstalled the motor.

I have NOT cleaned the idle stabilizer...that will be my next task after your suggestion...thanks for making it !

The 0.00v O2 sensor readings are constant @ -0.01 and 0.00

Thanks again for every ones help and keep the suggestions coming.