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Discussion Starter · #1 ·
Hi - found lots of good info on this forum from searching,vbut can't quite find this one:

89 lx, 363, COP, Pro-M intake and MAF/TB combo system. No crank trigger.

I've had struggle with the cam sync from day 1, been fighting this for about a month. Car starts, gets up to operating temperature, and will not always start again. First I replaced the distributor after reading the horror stories folks have with low quality aftermarket units. Since you can't get motorcraft, I bought a Performance Distributors forged unit for a 94-95, figured ditching the TFI module could only make things simpler/better. Chris said it would work. Wired it up - worked fine right away. I've now done two drives where the car won't restart after getting to operating temp. Looking at the data, when in this no-start condition, I am not getting EPOS_Sync_Level progressing past unsynchronized. So that would point to the distributor, but I find it so odd that it would work when cold and then not restart after being shut off. If the PIP sensor was failing when hot I would think the car would stop running randomly, but if it's running it stays running. When I pull the distributor out and spin it with a drill while watching the laptop, sometimes it does take a good 2-3 seconds to progress to Sync_720. I'd say 1 in 10 are slow. But it does always get to Sync_720

Other detail which I think is unrelated, so may be less relevant: I'm presently tuning base idle, fighting an off-idle drive ability issue. It stutters when coming right off idle, and dies when coming to a stop occasionally. I have 17" Hg of vacuum, and I removed all vacuum hoses and hooked up a gage at the throttle body and saw the same, so I don't think it's a vacuum leak. I haven't done a smoke test.

Help with either issue greatly appreciated!
 

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i see a fresh an open element breather on the ps valve cover and a pcv sucking in unmetered air because of it.

You can't run an open air breather with a pcv system and mass air. it causes a huge vac leak. Seeing your pi corrections with bank 2 adding a ton of fuel is the result.

Quick test:
Unplug the pcv, leave the hole open to atmosphere. cap off the manifold vac line. you will see that your pi corrections will need to be adjusted but both needles will be very close. Adjust the pi corrections according to the directions of the pro m. click save and write to the processor. after that, bring up the special functions and clear all adaptives.

The Fix:
Remove ds valve cover and install another baffled vent similar to whats on the ps. Keep the old vac line to the pcv capped off.
Merry Xmas
 

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I disagree.

Yes, PCV with an open breather is an unmetered air leak, but it should manifest as a lean condition on both banks, not just one.

There is a very large discrepancy between banks here. Possible causes for the “lean” bank:

  • Misfire on that bank
  • Leaking injector o-rings (bottom) on that bank
  • Leaking intake manifold gasket on that bank
  • Lower compression on that bank
  • Faulty wideband on that bank and it’s actually not lean at all
 

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'90 Windveil Blue LX (Dart Turbo T56)
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i think john's onto something and would get a smoke machine and check for leaks. also, invest in some arp studs especially for the intake as they not only help you guide the intake during the install, but more importantly hold the torque better over time as the upper section of the stud uses fine thread, so even if it loosens up (they always do) it won't be as much as a standard coarse threaded bolt or stud would.

on a side note, what power steering pump are you running?
 

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I disagree.

Yes, PCV with an open breather is an unmetered air leak, but it should manifest as a lean condition on both banks, not just one.

There is a very large discrepancy between banks here. Possible causes for the “lean” bank:

  • Misfire on that bank
  • Leaking injector o-rings (bottom) on that bank
  • Leaking intake manifold gasket on that bank
  • Lower compression on that bank
  • Faulty wideband on that bank and it’s actually not lean at all
If the breather was in a central location Id agree, but its on the ps. only the ps is adding fuel. the numbers, giving that his fuel injector data is correct and entered correctly, are so screwed from trying to dial in the pi corrections close to "0", he might have other issues that need correcting.
vac is being pulled on the crankcase and its sucking in unmetered air. this is causing a lean condition that is being seen on the ps wb. IF the rest of his engine is up to par, then this is the cause. Not saying that he might have other issues, like all that you stated above, but its definitely not right. CR had me remove my entire head and have it checked out before I found the open element problem. So, now when I see a pro m user with an open element breather and pcv, I know its wrong.

And IF his engine is good, injectors, gaskets, etc, a smoke test will not show a leak. The leak is only present when the engine is running. Been there.

It cost me a lot of time and aggravation to realize I pulled a new head for nothing.

A proper pcv in a maf system needs low pressure metered air plumbed before the tb blade, that way when the pcv pulls a vac, pulling metered fresh air through the crank case and back into the intake. you put on a open air breather and the whole thing goes belly up.

Anyway how long does it actually take to check? 30-35 seconds? Either run a pcv properly or dont run one at all and connect both valve covers to a catch can.
 

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Discussion Starter · #11 ·
i see a fresh an open element breather on the ps valve cover and a pcv sucking in unmetered air because of it.

You can't run an open air breather with a pcv system and mass air. it causes a huge vac leak. Seeing your pi corrections with bank 2 adding a ton of fuel is the result.

Quick test:
Unplug the pcv, leave the hole open to atmosphere. cap off the manifold vac line. you will see that your pi corrections will need to be adjusted but both needles will be very close. Adjust the pi corrections according to the directions of the pro m. click save and write to the processor. after that, bring up the special functions and clear all adaptives.

The Fix:
Remove ds valve cover and install another baffled vent similar to whats on the ps. Keep the old vac line to the pcv capped off.
Merry Xmas
I'm not following- I did exactly what Pro-M's instructions call for. I know it's unmetered air but i assume the qty is low enough such that it doesn't matter, otherwise Chris wouldn't put it in the instructions:

Rectangle Font Handwriting Circle Number


Would you still recommend I try this quick test?
 

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Discussion Starter · #12 ·
If the breather was in a central location Id agree, but its on the ps. only the ps is adding fuel. the numbers, giving that his fuel injector data is correct and entered correctly, are so screwed from trying to dial in the pi corrections close to "0", he might have other issues that need correcting.
vac is being pulled on the crankcase and its sucking in unmetered air. this is causing a lean condition that is being seen on the ps wb. IF the rest of his engine is up to par, then this is the cause. Not saying that he might have other issues, like all that you stated above, but its definitely not right. CR had me remove my entire head and have it checked out before I found the open element problem. So, now when I see a pro m user with an open element breather and pcv, I know its wrong.

And IF his engine is good, injectors, gaskets, etc, a smoke test will not show a leak. The leak is only present when the engine is running. Been there.

It cost me a lot of time and aggravation to realize I pulled a new head for nothing.

A proper pcv in a maf system needs low pressure metered air plumbed before the tb blade, that way when the pcv pulls a vac, pulling metered fresh air through the crank case and back into the intake. you put on a open air breather and the whole thing goes belly up.

Anyway how long does it actually take to check? 30-35 seconds? Either run a pcv properly or dont run one at all and connect both valve covers to a catch can.
Can you say more about how your engine was running with the open element crankcase breather?
 

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I'm not following- I did exactly what Pro-M's instructions call for. I know it's unmetered air but i assume the qty is low enough such that it doesn't matter, otherwise Chris wouldn't put it in the instructions:

View attachment 1093446

Would you still recommend I try this quick test?
I know Chris says this. I disagree with him. (I'll get a text tomorrow :)) It bumps corrections to 25% on my car. Adaptive fuel with Insight can help mask it much better that UTune could without adaptive. Regardless, in this matter overall I agree with kjb302ho. It's an unmetered air leak and air leaks are bad. Avoid it. You don't need to do this. You can easily run PCV the right way provided you are draw through MAF. Blow through, no. Some people have come up with their own recommendations for blow through. I don't agree with them either.
 

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If the breather was in a central location Id agree, but its on the ps. only the ps is adding fuel. the numbers, giving that his fuel injector data is correct and entered correctly, are so screwed from trying to dial in the pi corrections close to "0", he might have other issues that need correcting.
vac is being pulled on the crankcase and its sucking in unmetered air. this is causing a lean condition that is being seen on the ps wb. IF the rest of his engine is up to par, then this is the cause. Not saying that he might have other issues, like all that you stated above, but its definitely not right. CR had me remove my entire head and have it checked out before I found the open element problem. So, now when I see a pro m user with an open element breather and pcv, I know its wrong.

And IF his engine is good, injectors, gaskets, etc, a smoke test will not show a leak. The leak is only present when the engine is running. Been there.

It cost me a lot of time and aggravation to realize I pulled a new head for nothing.

A proper pcv in a maf system needs low pressure metered air plumbed before the tb blade, that way when the pcv pulls a vac, pulling metered fresh air through the crank case and back into the intake. you put on a open air breather and the whole thing goes belly up.

Anyway how long does it actually take to check? 30-35 seconds? Either run a pcv properly or dont run one at all and connect both valve covers to a catch can.
I agree with you here for the most part, but not about a lean condition being bank specific because of the location of the breather. Its location on the pass valve cover makes for no additional air routing solely through the pass intake valves. The air will enter the crankcase in general. It matters not from where. A vac line on the upper intake will draw in the air from the crankcase and then split it 8 ways. 1/2 will go to 1-4 and 1/2 will go to 5-8. The only reason for that not to happen would be if the PCV line connected to a runner rather than to the plenum. I would be very surprised if that’s how this intake is designed, but I am not familiar with it.
 

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Discussion Starter · #16 ·
I know Chris says this. I disagree with him. (I'll get a text tomorrow :)) It bumps corrections to 25% on my car. Adaptive fuel with Insight can help mask it much better that UTune could without adaptive. Regardless, in this matter overall I agree with kjb302ho. It's an unmetered air leak and air leaks are bad. Avoid it. You don't need to do this. You can easily run PCV the right way provided you are draw through MAF. Blow through, no. Some people have come up with their own recommendations for blow through. I don't agree with them either.
Yes I certainly would have run it the standard way if I didn't have this style of MAF which sits on the throttle body - there's nowhere to sample metered air from really.
 

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Discussion Starter · #18 ·
i think john's onto something and would get a smoke machine and check for leaks. also, invest in some arp studs especially for the intake as they not only help you guide the intake during the install, but more importantly hold the torque better over time as the upper section of the stud uses fine thread, so even if it loosens up (they always do) it won't be as much as a standard coarse threaded bolt or stud would.

on a side note, what power steering pump are you running?
That's a turn one steering pump. It's a GM Sagniaw type 2 pump. I built the mounting bracket. So far I love it. Makes no noise at all, perfect amount of assist. Driven all of 5 miles....
 

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Yes I certainly would have run it the standard way if I didn't have this style of MAF which sits on the throttle body - there's nowhere to sample metered air from really.
You’re right. I wasn’t thinking that is what you have.

Unplug the PCV line from the intake and cap off the fitting on it. You’ll just vent through the breather while you do that and you’ll be fine. Then you’ll be able to see what kind of corrections you really have. My guess is both needles will swing considerably left - like driver removing a lot of fuel and pass around 0.
 

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I suppose it’s possible that that particular intake manifold setup doesn’t distribute air evenly at low rpm and the spread between banks that you’re seeing is “normal.” I don’t know. I’d find it surprising. If you bring the engine speed up to 2000 do the corrections between banks stabilize? I’d try that with the PCV plugged if the discrepancy is still there.
 
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