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Old 02-26-2014, 09:50 AM   #281
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Quote:
Originally Posted by Reverant View Post
50% PWM DC doesn't mean that the valve is in the middle position. Try it with a valve on the bench and you'll see. With a 50% DC, it will eventually open up fully.
I would love to try it on a bench, but I don't yet have the equipment to do so.

tell me if I am wrong in my thinking: the solenoid has 2 positions on and off, which correspond to advance and retard (not 100% sure which is which, but I believe off corresponds to retard). A PWM of 50% means that solenoid spends as much time in the on position as the off position. So with the oil pressure spending roughly equal time on either VVT chamber, the phasor would tend to hold its position.

While I was thinking about this last night, It occurred to me that there is another component I was missing. The torque that the timing belt applies to the cam gear will tend to increase the pressure in the advance chamber. In order for the cam to hold its position, you would need to compensate by applying more engine oil pressure to the retard chamber. This would explain why in practice, you typically need less than 50% to maintain position.



Quote:
It's not going to make oil pressure until it starts. The engine has to spin the oil pump fast enough to make pressure.
The engine makes a little bit of oil pressure while cranking. If you want you can take the banjo bolt off of the back of the valve cover and crank it without starting. Oil will eventually spill from the tube. Don't ask me how I know this.


Quote:
I doubt you can do that due to lack of oil pressure, as it's the pressure that works against the spool valve to advance the cam.
It might actually start then die. The VVT is mechanically locked to retard after the motor shuts down. I imagine it would start, then oil pressure would advance the cam and then it would die.

basically exactly what rev said.
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Old 02-26-2014, 10:45 AM   #282
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Ok, well yesterday I didn't get 1 single minute to touch the car, and today looks like it will be no better. So Tomorrow and Friday will be when I get to wrench on it again.

But in the meantime, here goes:
Quote:
Originally Posted by EO2K View Post
How about the main ground strap that goes from the head (maybe block or bellhousing?) to the bolt by the master cylinder? I missed that one when I put the heads back on my truck. Drove me ******* bonkers trying to get it started.
Yep, that one is good too. I actually double checked all of them, but I supposed it won't hurt to do it yet again and possibly clean all of them as well (though they're really clean as is)
Quote:
Originally Posted by Chiburbian View Post
I am thinking, considering that the problem all started after you did your head work, pay extra attention to anything that you modified, moved, touched, looked cross eyed in the process of your work.
I removed cams, carefully measured and adjusted each shim/bucket individually, taking them out 1 by 1 and putting them right back in after I was done with it. Nothing I can think of that was done wrong, and that was literally all I did.
Quote:
Originally Posted by sharkythesharkdogg View Post
Any other major grounds, not in the engine bay, that could make this happen? Could some of the ECU harness wires been damage from swapping ECUs around? Have you done a continuity test on all the wires involved in getting spark signal and all that jazz to the ECU?
Nope, stock ecu is bolted down in its original location, the wiring harness from the MS going to ecu is also secured. I literally unplugged the 3 ecu connectors and plugged them in a couple inches away. Nothing was broken or damaged to my knowledge. But I'll unplug and inspect again I guess.
Quote:
Originally Posted by bcrx7 View Post
Did you put the square top intake on at the same time? Any way it might have a rag in it? How about the vacuum line to ECU (I guess that doesn't matter with stock). Fuel pump fuse? With the stock ECU back in there, does the stock fuel pump fuse gave to go back on (ST-SIG, not sure if the 2001 has it to or not). You have not forgot to connect the fuel lines or perhaps have them backwards (I have seen it before!)
You do have power at the injectors (I am guessing 2001 injector harness has its own plug as well, so checking to see if the plug is connected). Is it possible the valve lash is too tight and keeping valves open? That could explain the backfire through intake too. I'm just throwing things at it now that I can think.
Yeah checked all fuses, all are good.
I also double checked lash yet again, all is still good.
Quote:
Originally Posted by EO2K View Post
What exactly did you touch when you did the lash?

Is it possible that you have a chunk of whatsit that came from wherever stuck in the VVT actuator, or that it could have possibly moved down the line and its now affecting oil flow and regulation for the whole VVT system? Stuck at the cam or in one of the passages? I haven't looked for a flow diagram, but where does oil go after the VVT hardware gets done with it?
Nope. Posted process above- each was done individually, carefully cleaned and carefully re-installed. The chances of them being contaminated or with chunks of metal on them are 0%
Quote:
Originally Posted by EO2K View Post
Lets think of it this way: I thought I read earlier someone posted that 50%DC on the VVT chingaderas was 0 or "neutral" in terms of advance/retard. As I was trying to get to in my earlier post, does more oil pressure cause it to advance or retard? I know we can't measure the pressure directly, but we can infer its getting too much or not enough from what we are seeing? I'm just trying to figure out if there is a way to determine a blockage or surplus in flow.

Maybe I'm way off base Don't drink and think kids
Not sure about that. But that does make sense given what I've seen when opening it up: it needs pressure on both sides to maintain 0*
Though when its locked in place I don't think any of this matters?
Quote:
Originally Posted by richyvrlimited View Post
Vlad needs to do a datalog with the crank and can patterns I bet everything is still skew wiff still in spite of the can change.

The lack of starting is due to this. No sync, no start. What's causing it is the question
Its nothing to do with injectors, or vac ports.
Absolutely I will asap
Quote:
Originally Posted by Davezorz View Post
I think 50% DC is "hold position". Because oil is always flowing through the actuator, it is always trying to change position. The way to get it to hold a position that is not fully advanced or retarded is to with 50% PWM. Since the mechanical portion of the VVT cannot move as fast as the solenoid, it ends up not moving at all.

I am having a hard time thinking of where an oil blockage could be that would only cause the cam to advance. much of the oil control system flows in both directions, which would imply the blockage is acting as a check valve. this my be due to my poor understanding of the oil control in the system. I will try to take a closer look at my car when I get a chance and see if I can find something.
I am certain there is no oil blockage anywhere. This engine is clean as a whistle. Only that vvt cam gear I had was a bit dirty inside as I posted, but that's replaced now with a 100% good one.
Quote:
Originally Posted by Chiburbian View Post
Can you command 0% and 100% duty on the VVT while cranking? It would be interesting to see what the resulting cam angles would be in those completely opposite situations. In other words, if there is enough oil pressure at cranking speed to fully retard/advance the cam, does the cam in fact respond to changes in VVT duty?
Doubt it. No, it doesn't respond to any vvt changes at all when cranking
Quote:
Originally Posted by bcrx7 View Post
Mmh not sure if there is enough oil pressure for the VVT to work correctly at cranking.
Quote:
Originally Posted by NiklasFalk View Post
Just one question need answering, does it run?

If not, composite log, cams identical, ...?
Nope.
And yes will do asap.
Quote:
Originally Posted by z31maniac View Post
You said it has fuel, right? Have you yanked the fuel hose off the rail to make sure it's actually coming out when you crank it over?
Yep, sure does. Fuel is 100% good.

Quote:
Originally Posted by Reverant View Post
For the love of god.

A datalog. PLEASE.
YES!!
Sorry, its been crazy, I will take more logs as soon as I possibly can.

Quote:
Originally Posted by Chiburbian View Post
I am half tempted to force my VVT to 100% and attempt to start my car just to see if it will start. I am just wondering how far out of alignment the cam has to be before it won't start.

(for SCIENCE!)
Quote:
Originally Posted by Reverant View Post
For science, it will always start but it won't idle, it will just die violently a few seconds later if you don't give it some throttle.
Quote:
Originally Posted by Ben View Post
I doubt you can do that due to lack of oil pressure, as it's the pressure that works against the spool valve to advance the cam.

Lack of oil pressure will not prevent a motor from starting.
Lack of oil pressure will damage bearings.

At full advance (like stated by Reverant), it will be reluctant to idle.
Quote:
Originally Posted by EO2K View Post
Brings up a good point though, is this thing making oil pressure?
Yes, this thing absolutely has oil pressure.
When I was cranking it over earlier I could very clearly see the oil pressure swtich rising quickly.
Quote:
Originally Posted by Blue_Heron View Post
It's not going to make oil pressure until it starts. The engine has to spin the oil pump fast enough to make pressure.
If you crank it for like 10 seconds it will build oil pressure. It has.
Quote:
Originally Posted by EO2K View Post
I believe he said it ran for some very short duration of time after the lash was set, then it died never to restart again. I'm wondering if it came up to pressure in the short period of time.
What came up to pressure? the vvt system? probably. But I yanked the vvt cam off like 3 times after that, as well as disconnected the vc with the vvt oil line, so any pressure would have dropped.

Thanks for contributing guys, I appreciate it, and keep the ideas coming.

As soon as I get the chance to tinker with it more I will throw everything back together (currently removed crank pulley to check and make sure the little pin and everything in there is correct - it all looks perfect) and get more composite and regular logs.
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Old 02-26-2014, 11:35 AM   #283
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Are there any relays that could go bad and cause a no start?
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Old 02-26-2014, 11:43 AM   #284
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props for the awesome multiquote
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Old 02-26-2014, 01:26 PM   #285
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Seriously, that took some dedication
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Old 02-26-2014, 01:43 PM   #286
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Quote:
Originally Posted by richyvrlimited View Post
props for the awesome multiquote
You do realize there is a multiquote button right next to the quote one right? Makes doing lots of quotes a piece of cake.
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Old 02-26-2014, 01:59 PM   #287
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Quote:
I am certain there is no oil blockage anywhere. This engine is clean as a whistle. Only that vvt cam gear I had was a bit dirty inside as I posted, but that's replaced now with a 100% good one.
how do you know you got all of it? obviously the cam and gear would be fine, since those were replaced. What if some debris is trapped in the head somewhere? I doubt this is the problem, but I would be hesitant to say there is no oil blockage anywhere.
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Old 02-27-2014, 04:58 AM   #288
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Quote:
Originally Posted by shuiend View Post
You do realize there is a multiquote button right next to the quote one right? Makes doing lots of quotes a piece of cake.
Oh yes, but people rarely put the effort into even using that button.
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Old 02-27-2014, 10:13 AM   #289
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Quote:
Originally Posted by Davezorz View Post
how do you know you got all of it? obviously the cam and gear would be fine, since those were replaced. What if some debris is trapped in the head somewhere? I doubt this is the problem, but I would be hesitant to say there is no oil blockage anywhere.
Well obviously I don't really "know" about every single port, beyond a shadow of a doubt.

What I do know though, is that originally the cam gear would advance when trying to start the car, and never go back to full retard, never "snap back and lock" like it should.

And now it works/does that perfectly.
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Old 03-01-2014, 02:18 AM   #290
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You know what this thread needs? MOAR LOGS!





Attached Thumbnails
Fired up the new setup/engine, weird issue-logs.jpg   Fired up the new setup/engine, weird issue-hpim0463.jpg   Fired up the new setup/engine, weird issue-logs2.15113336_std.jpg  
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Old 03-01-2014, 11:17 PM   #291
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Logs attached.
Attached Files
File Type: csv 2014-03-01_19.11.27.csv (10.7 KB, 45 views)
File Type: msl 2014-03-01_19.12.03.msl (172.6 KB, 71 views)
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Old 03-02-2014, 04:37 AM   #292
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Yeah, it doesn't look good, hence the no start condition.

Replace both the crank and the cam sensors if you have spares as a precaution.

Inspect the trigger wheel, make sure it is on the right way. With cyl #1 on TDC, there should be a tooth under or very, very near the sensor.

And for the 256th time, make sure the intake cam is installed/phased properly.
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Old 03-02-2014, 06:21 AM   #293
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Quote:
Originally Posted by Reverant View Post
Yeah, it doesn't look good, hence the no start condition.

Replace both the crank and the cam sensors if you have spares as a precaution.

Inspect the trigger wheel, make sure it is on the right way. With cyl #1 on TDC, there should be a tooth under or very, very near the sensor.

And for the 256th time, make sure the intake cam is installed/phased properly.

rpm signal and injector duty cycle are very unstable and both constantly dropping to zero while cranking
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Old 03-02-2014, 12:06 PM   #294
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Can you bring the engine to TDC #1 and take a picture of the both cams with the cover off?
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Old 03-02-2014, 12:26 PM   #295
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Looking for win here. Sounds like progress is about to happen.
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Old 03-02-2014, 12:45 PM   #296
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Reverant, I posted my 01' VVT logs earlier in the thread to compare against... Are there any logs that I can provide that might help? Under any specific conditions?
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Old 03-02-2014, 12:49 PM   #297
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I can't open the composite log on my home computer.
Datalog implicates lack of cam sensor.

**different problem** than before. The best tool for this job is a scope. Without one, you can replace the cam sensor and you can perform a pinpoint check on the wiring with a DMM. You can also backprobe the signal out pin on the cam sensor and you should be able to see the cam sensor output switch between ~0V and ~5V when you spin the motor by hand. If you do that test, MAKE SURE THE MOTOR CAN'T START (unplug coils and/or injectors).
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Old 03-02-2014, 12:53 PM   #298
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I remember someone saying one time that due to heat at the back of the motor the wiring to the cam sensor on VVT motors is prone to insulation breakdown or other wiring problems.

Might be worthwhile to take an extra hard look at all of that.
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Old 03-02-2014, 01:21 PM   #299
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The cam sensor signal is there, its out phase though and crosses with the crank signal, hence a no sync condition. It looks like a no-cam condition if you were to judge by the datalog alone; its not.
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Old 03-02-2014, 01:41 PM   #300
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Thanks all, will do. I will yank spare crank and cam sensor out of a known running car and try again with a 3rd set of cam/crank sensor.
The cam I'm using is EO2K's cam, so we can rule that out. Timing is set correctly, so that's out. The wiring is completely unmolested, so that's out too.
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