P0335 crank position sensor malfunction

[RC_slow_dsm]

First of all my profile is up to date. 7 bolt /w oil jets plugged on DSMLink.

I just finished installing my bc cams (272/272) and it fired right up. It was running pretty rich, but idled fine for about 10 minutes. I then shut it off to check everything, started it back up, and it ran for another 5 minutes and died. From then on it wouldn't even crank over.

DSMLink threw the P0335 crank position sensor malfunction. Immediately I checked the voltage on the CPS connector with these results:
11.5 voltage on one pin (book says it just has to have voltage)
5.0 voltage on another pin (book says between 4.8-5.2)
And continuity on the last pin, which complies with the book.

I then went ahead and replaced the sensor itself. I cranked it over a few times before putting the timing cover back on just to make sure it worked. After putting the cover, belts, etc.. everything else back on it started right up, but had some sort of noise so I shut it off again and now it WONT start again.

Its throwing the P0335 code AGAIN on the new sensor (which I KNOW is good i pulled it off a running motor).

Ive narrowed it down to:

1) the CPS trigger plate , which was never removed during cam install. I checked the clearance between the sensor and trigger plate with a feeler gauge and got appx. .020. Is there a specified clearance?

So the trigger plate might be bent, which caused the first sensor to go out, and is making the second sensor malfuntion.

2) the ECU may have some sort of problem, its only about 2 weeks old though since I got it back from ECMLink.

I have a spare ECU and trigger plate that I'm going to try tomorrow, but I want opinions before I tear the timing apart, or try another ECU.

Ive also double checked that the power transistor is plugged in, and ive tried the CAS both ways it goes into the camshaft. They are both fine.

 

[luv2rallye]

Unlikely it's the ECU.
Those voltages are with CPS disconnected. When connected and cranking blue/white to ground should be 0.4-4.0V. When idling it should read 1.5-2.5V.
Better check for crankwalk which would explain why sensor may be hitting trigger plate.
Check your FWD for crankwalk.

 

[RC_slow_dsm]

The engine won't crank or idle, so i have no way of testing those voltages while its connected. I'll check for crankwalk, but i'm 99% sure I don't have it. My main concern is the gap between the trigger plate being to close or far, if that matters.

 

[RC_slow_dsm]

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tried the new trigger plate last night with no luck. also checked for crankwalk and it passed. is there some sort of bad ground that i can look for? I'm trying my stock 97 ecu tonight.

 

[luv2rallye]

The engine won't crank or idle, so i have no way of testing those voltages while its connected.

Do you get any spark from any plug at all (pull plugs, reconnect and look)?
If not, check for that CPS voltage to be there while cranking the starter (when connected and cranking, blue/white wire to ground should be 0.4 - 4.0V.). Stick a safety pin through the blue/white wire's insulation to reach the wire and connect voltmeter positive to it. Then watch meter while a friend cranks the starter.

 

[RC_slow_dsm]

Do you get any spark from any plug at all (pull plugs, reconnect and look)?
If not, check for that CPS voltage to be there while cranking the starter (when connected and cranking, blue/white wire to ground should be 0.4 - 4.0V.). Stick a safety pin through the blue/white wire's insulation to reach the wire and connect voltmeter positive to it. Then watch meter while a friend cranks the starter.

We checked everything just now with these results:

1st: sensor unplugged, voltage read 5.0v at the connector, and 5.0v on the blue/white wire before the connector.

2nd: plugged the sensor back in. the fuel pump briefly primed and a relay clicked. My friend in the drivers seat reported the battery light flicking on and off once very quickly.

The sensor read .3v on the blue/white wire before the connector with the ignition in the ON position. When trying to start the car, the voltage stayed at .3v.

The starter doesn't crank over or click at all. Also when cranking the engine over by hand with a ratchet, at certain positions the fuel pump primes.

Since I relocated the battery every once in a while the battery light would flicker on and off once. could this be a bad ground somewhere?


Also for the spark test... the engine won't crank over by the ignition switch, but when we crank the engine manually with a ratchet we get spark to the plugs.


thanks for your help btw much appreciated.

 

[luv2rallye]

Since you get spark it sounds like the CPS, CAS, PT, and coil are all working. The 0.4-4.0V is only while crank is spinning faster by the starter. With just hand spinning by a rachet, you could easily only read 0.3V (it's a pulse so turning too slowly you may barely read anything).

You need to get that starter working to proceed. 90% of the time a non-functioning starter is due to poor "battery to starter" cable connections (from too high resistance there, even 0.1 ohm is too much - causes too high voltage drop with the high current). You need a minimum of 9.6V on the positive starter terminal (at the starter - not the battery) while trying to crank starter or it will not work. Take both ends of both battery cables off, clean them with wire brush and then sand paper, clean battery posts with sand paper, retighten them. Battery negative cable should go under a starter mounting bolt (to minimize resistance), not to block. If have battery in trunk and negative goes to frame (make sure it's large enough, clean, and tight), put another cable from frame to starter mounting bolt. Battery must also have enough power to drive starter (typically 80-150 amps depending on load) without dropping voltage much.

If it still doesn't click when cranking, check starter relay, clutch position switch, and then finally ignition switch itself.

When starter gets working, try another ECU if it still doesn't run.

BTW sticking a safety pin through the wire insulation is just a way to get at the wire when the connector is plugged in (so when unplugged you don't need it).

 

[RC_slow_dsm]

Since you get spark it sounds like the CPS, CAS, PT, and coil are all working. The 0.4-4.0V is only while crank is spinning faster by the starter. With just hand spinning by a rachet, you could easily only read 0.3V (it's a pulse so turning too slowly you may barely read anything).

You need to get that starter working to proceed. 90% of the time a non-functioning starter is due to poor "battery to starter" cable connections (from too high resistance there, even 0.1 ohm is too much - causes too high voltage drop with the high current). You need a minimum of 9.6V on the positive starter terminal (at the starter - not the battery) while trying to crank starter or it will not work. Take both ends of both battery cables off, clean them with wire brush and then sand paper, clean battery posts with sand paper, retighten them. Battery negative cable should go under a starter mounting bolt (to minimize resistance), not to block. If have battery in trunk and negative goes to frame (make sure it's large enough, clean, and tight), put another cable from frame to starter mounting bolt. Battery must also have enough power to drive starter (typically 80-150 amps depending on load) without dropping voltage much.

If it still doesn't click when cranking, check starter relay, clutch position switch, and then finally ignition switch itself.

When starter gets working, try another ECU if it still doesn't run.

BTW sticking a safety pin through the wire insulation is just a way to get at the wire when the connector is plugged in (so when unplugged you don't need it).

Could not find a safety pin, but i just dug at the insulation with the voltmeter probe which worked fine.

The battery is a brand new dry cell mounted in the trunk with i believe a 4ga ground to the spare tire well. The starter ground has the same gauge wire from a mounting bolt to the firewall. I will check the grounds tonight. The starter to firewall ground wire is kind of long, but i'm not sure if it would effect the resistance that much seeing as the car ran fine for almost a year before this happened. My engine bay got really oily from an oil pressure gauge line blowing off, could an oily ground cause this big of an issue? I'll clean it up tonight anyway.

here is a thread with a diagram for my battery relocation just as a reference: http://www.dsmtuners.com/forums/newbie-forum/294595-battery-relocation-w-diagram.html the second pic is how I have mine configured.

 

[luv2rallye]

My engine bay got really oily from an oil pressure gauge line blowing off, could an oily ground cause this big of an issue?

If the voltmeter probe tip is sharp enough to penetrate the wire insulation, that's fine.

Yes, oil on wire connection points can cause problems since it is an insulator and tends to seep into the connection point. Disconnect connections, clean, and retighten them.

Are you getting +12V on the black/red wire of the starter relay when starting? Also the black/yellow? (Note: the relay activates to DISABLE the starter - so normally the black/red is connected to the black/yellow inside the relay unless the clutch pedal is up or theft alarm is activated either of which activates the relay).

 

[RC_slow_dsm]

Cleaned the ground from the starter to firewall, it was pretty dirty and some electrical tape was melted. Cleaned the battery ground as well.

Checked the voltage on the red/black wire that goes to the starter, got 12.7v with the ignition in the ON position, the voltage did not drop while trying to start using the ignition.

Checked the voltage on the yellow/black wire on the starter relay. It showed no voltage with the ignition in the ON position, and rose to 10.3v while trying to start using the ignition.

all of these measurements were taken while the battery was being jumped by a running car.

My clutch switch is unplugged to prevent crankwalk.

 

[RC_slow_dsm]

I'm completely in awe of what just happened.

My friend and I are staring at my engine bay thinking, the starter has power to it, and so does the relay. He says that the same thing happened on a car of his once so he hit the starter relay with a wrench a few times and it worked. I get under the car and try it out, because i might as well kill time. I was planning on getting the starter checked out tomorrow anyway.

I hit the starter a few times and it cranks right over. so apparently the relay was just cold or something.

I always overthink the situation but at least it starts and the problem is solved.

Thanks for all your help I definately understand why your a wiseman.

 

[luv2rallye]

Your starter should be working every time when you have 10.3V on the black/yellow wire. Therefore your starter is intermittent and needs to be fixed/replaced or this will keep happening. BTW your hitting the starter solenoid not the starter relay (which is under the radio).