Resolved 2Ga Crankshaft Position Sensor cleaning & test fire help

[1greyawdtsi]

Hi. My 95 Talon Tsi awd 5 speed had intermittent power loss for a couple days then fortunately at home in my garage it devolved into a no start condition. Like the kids say I reflexively threw my purse at it and I installed a larger fuel pump - to no avail.
So I grabbed an OBD2 reader and it threw 1 code - 0335 Crankshaft Position Sensor A Circuit.
I pulled the accessory belts and timing covers. Note I’ve had a slightly leaky power steering pump for years and it looks like a little oil and dirt over the years gummed up the crankshaft position sensor and trigger plate was also slightly dirty & oily but otherwise fine.
I’ve carefully cleaned the area and the CP sensor and all timing marks are good. I’ve searched but found no threads. So my question is if every thing is safely out of the way is it reasonable to test fire the engine to see if the cleaning the CP sensor & trigger plate may have worked - before I replace it?
I realize the water pump would not be circulating. If it fired it would only be running for a minute or two.
Before I attempt that I’m was curious if I’m missing something or shouldn’t attempt to start or fire the engine with all the accessory belts and all timing covers removed? Any insight is appreciated, thanks!

 

[1990TSIAWDTALON]

You can test start it, just don't let it keep running. Double check that everything is out of the way of the timing belt area for those brief few seconds.

 

[1greyawdtsi]

You can test start it, just don't let it keep running. Double check that everything is out of the way of the timing belt area for those brief few seconds.

Thanks I appreciate that! I kept thinking with everything out the way - it should be safe for a minute.
But sometimes having no real world
experience in areas makes you really question things…

 

[pauleyman]

Thanks I appreciate that! I kept thinking with everything out the way - it should be safe for a minute.
But sometimes having no real world
experience in areas makes you really question things…

I've done what you suggest. I second, make damn sure nothing is in the way or could fall in the way. You'll probably only need 10 or 15 seconds? Totally safe.

 

[luv2rallye]

You also can test the CPS with a multimeter (https://www.dsmtuners.com/threads/wont-start-new-head.379677/post-152302942). When cranking the Blu/White is a pulse but the meter will read an average so it should not be either 0v or 5v or it's bad (my 99 GST read 2.4vdc while cranking).

 

[1greyawdtsi]

Just to follow up: expand, help, and hopefully Resolve the problem in this thread.
After cleaning CPS and test firing / attempting to start the car it was still in a crank but no start condition. Upon closer inspection I found one of the 3 wires to the CrankShaft Position Sensor CPS itself damaged, (see Pictures) not cut but bare wire exposed. I purchased a Duralast CP sensor from Autozone for about $50, installed it and again test started it with all accessory belts, pulleys, timing covers removed and Everything out of the way! It started right up and ran fine for about a minute.
I’ll also add if anyone else needs help. You can remove and replace the Crankshaft Position Sensor without removing the timing belt. I used dull Needle Nose pliers to carefully twist the timing belt directly to the right of the sensor (see Picture) and took my time and I was able to maneuver, angle & slip the Sensor behind the belt. It takes patience and it’s a bit of a puzzle but can be done.
I appreciate the earlier assistance, thanks!

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[pauleyman]

Just to add a note, if you have all the covers off and everything exposed I don't see the need to twist and fiddle with the belt. Just take it off and put it back on. I say this also knowing I can install and tension a belt in just a few minutes. Just a thought. Glad you got this resolved.

 

[1greyawdtsi]

Thanks! Totally agree. All my timing marks were good after dozen or so clockwise rotations and that was almost my next step. I was being lazy and trying to save a little time.
It is def worth a mention that you can easily damage the Crankshaft Position Sensor if you try to sneak it behind the belt.

 

[1greyawdtsi]

Adding on to this thread - if allowed. After the test fire and a short/successful start up. I decided to send in my ECU to ECMTuning to have their Caps and Socket service done while I took my spare time to reinstall the timing covers, accessory pulleys/belts, etc..
In a timely manner I received my ECU back with the comments below:
“

ECU tests fine except for caps leakage that is starting to affect the circuit that detects injector circuit malfunctions. We'll think we can clean that up in the normal time for socket and caps so we'll proceed with the work, but if we find that the damage is more than is apparent upon initial inspection, it might end up requiring an additional 10 minute, $18 of work.

We were able to complete the clean-up without any additonal charge.”

So almost immediately after receiving & installing the ECU. The new issue is the car starts fine, idles smoothly and drives but dies or stalls immediately, once up to operating temperature/after about 5 minutes. Also it won’t start again until it cools most the way down.

This occurred a few times so I used an OBD2 DTC reader - now I’m getting DTC P1400 code / MDP in addition to the original CPS DTC P0355.

In less than a year I’ve already replaced plugs, wires, fuel pump, fuel filter, CSP sensor.
I did write ECM regarding this situation looking for any help or experience they may offer.

In the interim I’m hoping get to test the coil, ISC, Ignition Control Module/Power transistor, etc. My immediate leaning is toward an ECU issue. But I wondered if anyone had any thoughts or similar experience with a situation like this, thanks again!

 

[dustyboner]

It wouldn't surprise me if it was the durolast sensor. I won't buy anything from autozone anymore. they sell too much crap.

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[1greyawdtsi]

Thanks DustyB! I don’t disagree at all RE Autozone. I didn’t even think of that but guess I should have. I’ll have to test that sensor too. If it’s bad I’ll return it and go Genuine Mitsubishi.
Guess I’ll keep scratching my head and get after it tomorrow.

 

[luv2rallye]

IMO - I won't ever buy Durolast. Even if they initially work it won't be for long (eg. temperature sensitive is typical and terrible quality in all their stuff).

 

[TerminalTalon]

Just buy an NTK sensor and be done with it.

 

[1greyawdtsi]

I have tested the OEM fpr for vapor lock. And I tested the coil and the Ignition Control Module/Power transistor - these were within spec.
I guess my feelings are hurt that I’ll have to reproduce the work to remove the accessory belts, timing covers, replace crankshaft position sensor again, just to hope it runs properly. But It could always be worse…

 

[nismojones]

I’ve always bench tested CPS sensors by measuring resistance across the pins. If it has some it’s good, if there's no reading it’s bad. IDK if it’s proper, but I’ve never had an issue with this method, and it sure saves time since you can just unplug the connector and measure it without removing anything, GL

 

[luv2rallye]

2g CPS and CAS sensors use magnetic induced pulses so measuring resistance does not indicate they are good (can be bad even with proper resistance). You must measure DC voltage (average of the pulses) while cranking or running to know if good (unless you happen to have an oscilloscope, ha, ha). Here's proper way to test: https://www.dsmtuners.com/threads/wont-start-new-head.379677/#post-152302942.

 

[1greyawdtsi]

I’ve also continued reading and continued to run the car a couple times a day now to see how it runs. I’m at over a half dozen different attempts and the car stalls out every time it gets up to about normal operating temp (about 3-6 minutes). But starts every time it’s cold (ambient temp) Otherwise when it runs, it runs smoothly and idles fine until then.
One thing I keep reading/finding is that the ignition power transistor can become very sensitive to heat. I might just throw $150 at a new OEM Ignition Control Module/Power transistor from extreme psi first before I jump on swapping in another new crankshaft position sensor. Car is just over 200,000 miles and the power transistor by all appearances, looks original. Any thoughts?

 

[luv2rallye]

Yes a poor quality PT often fails with temperature (which is why you should stay away from inferior brands certain auto stores sell. Stay only with known brand names). Before throwing $150 at it, instead when engine is cold and running ok, heat the PT up with a hair dryer or heat gun and see effect. The PT also needs to be in its stock bracket bolted to the intake manifold to dissipate heat (and also for better grounding - the PT uses the bracket as another ground).

 

[pauleyman]

Throwing parts at it might fix it but it's an expensive way to diagnose.
If ignition transistor is bad the tach will not twitch when trying to start. Quick and dirty way to possi ly rule that part out. A better way would be to get the factory manual and use its diagnostic procedure with a multimeter. You can artificially get the part hot with a hairdryer. I had this problem on a 90 years ago. Car shut down like key turned off and would not start again until cooled down.

 

[1greyawdtsi]

Throwing parts at it might fix it but it's an expensive way to diagnose.
If ignition transistor is bad the tach will not twitch when trying to start. Quick and dirty way to possi ly rule that part out. A better way would be to get the factory manual and use its diagnostic procedure with a multimeter. You can artificially get the part hot with a hairdryer. I had this problem on a 90 years ago. Car shut down like key turned off and would not start again until cooled down.

Appreciate the input. Will try that & other suggestions before officially spending any more hard earned cash. Plus it’s getting pricey & I’m still baffled it has been this challenging to diagnose. Grateful the Talon is not my DD!

 

[dustyboner]

here is a link to download the pdf version of the service manuals
97-99_full_service_manual_Vol1 & 2

or if you just want the section on MFI troubleshooting
4G63_4G64_GST-GSX-Spyder_MFI_TroubleShooting.pdf

 

[1greyawdtsi]

here is a link to download the pdf version of the service manuals
97-99_full_service_manual_Vol1 & 2

or if you just want the section on MFI troubleshooting
4G63_4G64_GST-GSX-Spyder_MFI_TroubleShooting.pdf

Thank you.

 

[1greyawdtsi]

Fortunately I swapped out the ignition control module / power transistor with a working unit from a friend’s ‘95 GSX to no avail. Car still stalls once at operating temperature and again won’t restart after it stalls / dies out until cools down, same as before.

After various diagnostic testing, swapping or replacing suspect parts/sensors, hours & hours of reading - it really seems like the crank trigger plate is rubbing on the crank position sensor and heating up the sensor causing the ECU to cut the fuel. So seemingly at 200,000 miles perhaps there is enough crankshaft thrust bearing wear to cause the crank to walk to cause this rubbing & sensor failure.

Later today I’m going to have the wife press the clutch in and out and see what kind of movement I can observe on the crank pulley and listen to see if I can hear the ticking or trigger plate hitting the crankshaft position sensor. At this point nothing else really makes sense. Will follow up with my findings.

 

[Mello]

I doubt you have crankwalk after 200K miles. If the crank is going to walk it happens fairly quickly. You can measure the crank end play by unbolting the clutch slave so it isn't causing any preload from the pressure plate and than the crank will push-pull easily. Using a dial indicator or find a nice gap and use feeler gauges to see how far the crank can move. My beat is on the Autozone sensor being crappy out of the box.

Just buy an NTK sensor and be done with it.

 

[1greyawdtsi]

I doubt you have crankwalk after 200K miles. If the crank is going to walk it happens fairly quickly. You can measure the crank end play by unbolting the clutch slave so it isn't causing any preload from the pressure plate and than the crank will push-pull easily. Using a dial indicator or find a nice gap and use feeler gauges to see how far the crank can move. My beat is on the Autozone sensor being crappy out of the box.

Appreciate that. I am unsure about the possibility of crank walk at such high mileage I’ve read mixed threads. I was thinking if I don’t hear or see anything obvious when the wife is working the clutch later today - that it still might be worth my time to pull the Autozone crankshaft position sensor and try a genuine one from extreme psi.