Starts then stalls - after car wash - car is in a show tomorrow and won't start :/
11-01-2018, 02:38 PM
#31
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Thread Starter
With Helio's help, have got her to roughly idle. Just getting the 1/4 turn to rich on the mixture actually did that once Helio instructed me that it's a press-down to engage screw. Now she won't run up above idle though, so will be trying more mixture adjustment. Doesn't the car automate mixture via O2 and such? I really love my all-mechanical MFI on the '73 right now. 
I've ordered the LM2 and have a hand vacuum <<will that work or do I need something to make steady vacuum?
Hoping the won't-run-up-above-idle issue doesn't indicate anything nasty. Helio suggested if it doesn't cure with mixture tweaks etc it may be my sparkly clean looks-like-new 35K mile WUR is dead.
What's the best reference out there for testing/setting fuel pressures on our cars? Factory shop book section 25? Are pressure numbers same for 3.3 and 3.6?
I've ordered the LM2 and have a hand vacuum <<will that work or do I need something to make steady vacuum?
Hoping the won't-run-up-above-idle issue doesn't indicate anything nasty. Helio suggested if it doesn't cure with mixture tweaks etc it may be my sparkly clean looks-like-new 35K mile WUR is dead.
What's the best reference out there for testing/setting fuel pressures on our cars? Factory shop book section 25? Are pressure numbers same for 3.3 and 3.6?
Last edited by wicks; 11-01-2018 at 03:33 PM.
11-02-2018, 01:14 AM
#34
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Thread Starter
Update if it means anything: now with an idle happening based on 1/4 turn enriching mixture, adding another half turn she will now rev up into the 4-5,000 RPM ranges, however sluggishly with sputters and occasional backfires.
Last edited by wicks; 11-02-2018 at 03:07 AM.
11-02-2018, 10:17 AM
#35
Rennlist Member
The most common failure mode of the WUR is a ruptured diaphragm. This is usually accompanied by raw fuel being dumped into your air cleaner assembly. If this has happened you will know it.
If you do not have a Leask WUR, you will only be checking control pressures with no ability to change them.
When you have your LM-2, you can set your idle enrichment with it. Make it as close to stoich as you can (14.7/1).
The chart you posted is for cold control pressure. Obviously it is dependent on ambient temperature. It's really difficult to find the sweet spot where you fire the car up and immediately drive off without stumbling. It would take having your LM unit on a separate power source to see if it's a lean or rich stumble (one day I will buy a 12 v power source and do this myself
)I think you have the correct value for warm control pressure. I will double check it for you when I get home tonight. If it is incorrect and you can't adjust it, stop right there and send your WUR to Brian Leask (I believe he lives in the LA area). Have him install the heavier diaphragm if you want to raise the boost.
You can check the boost control pressure for practice but if the warm control pressure is off, boost pressure will be too.
Be careful ever using Streather's book. I have found some serious errors in it. Double check everything he says. "Without Guesswork" is a better source. The factory manual is good too. Also, pick up Posbt's book on CIS. It will help you understand CIS theory:
11-02-2018, 11:58 AM
#36
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Thread Starter
Thanks Paul. The WUR isn't dumping fuel - could it still have failed? Thinking to have Leask fix it with new diaphragm in any case now.
I'm also thinking since the air meter feels not as smooth and generally harder to depress since before my Friday test drive and subsequent failure to run, that could be shutting down air metering and thus fuel delivery. Wondering if there's a way to unstick that without taking fuel dist apart? Squirt some carb cleaner through a bent tube up into the plunger?
About to plug in AFR meter and see what it's looking like at this enriched idle...imagine it's going to show way rich as that idle fuel may be what's powering the engine all the way up to 4K RPMs now...
I'm also thinking since the air meter feels not as smooth and generally harder to depress since before my Friday test drive and subsequent failure to run, that could be shutting down air metering and thus fuel delivery. Wondering if there's a way to unstick that without taking fuel dist apart? Squirt some carb cleaner through a bent tube up into the plunger?
About to plug in AFR meter and see what it's looking like at this enriched idle...imagine it's going to show way rich as that idle fuel may be what's powering the engine all the way up to 4K RPMs now...
11-02-2018, 12:57 PM
#37
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Thread Starter
AFR:
at +1 full turn rich = 11.4
back off a half turn = 14.3
back off another 1/4 turn = 17.4
So I'll put back on 1/4 turn-ish to hit 14.7ish. This doesn't really solve much but interesting it may have been lean on idle (assuming something didn't change that during the "car wash" failure).
I'm thinking I better pull the fuel distributor and figure out why it isn't as light a touch to depress plate as it was before Friday test drive when all was swell.
While checking everything a 7th time for air leaks.
at +1 full turn rich = 11.4
back off a half turn = 14.3
back off another 1/4 turn = 17.4
So I'll put back on 1/4 turn-ish to hit 14.7ish. This doesn't really solve much but interesting it may have been lean on idle (assuming something didn't change that during the "car wash" failure).
I'm thinking I better pull the fuel distributor and figure out why it isn't as light a touch to depress plate as it was before Friday test drive when all was swell.
While checking everything a 7th time for air leaks.
11-02-2018, 09:04 PM
#38
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Thread Starter
This is hard to admit - I seem to have refilled with a bit too much oil. Decided to go back to the first thing I noticed wrong which was air plate/plunger not as smooth and drop of plunger slower than before. Pulling it off revealed oil goo sticking up the plunger. All clean now and smooth as silk and plunger drops nice n quick. Cleaned out MAF housing and such, oil seems to have just made it into the elbow area.
I didn't seem to get enough in to make it down to the turbo or up into the IC, but I do have a coating of oil inside the manifold. Not sure if I did that or if it was just there, as the path from the elbow down to turbo and all the way thru intercooler is dry. Wondering if there's a hack to clear the goo out from manifold while running or something as I'd rather not disassemble down to cylinders just to blow some cleaner through. But I will if I should...
If this cures her, I'll be sorry for wasting everyone's time. And will owe the car a solid for bitching about her here when she'd done nothing wrong.
I didn't seem to get enough in to make it down to the turbo or up into the IC, but I do have a coating of oil inside the manifold. Not sure if I did that or if it was just there, as the path from the elbow down to turbo and all the way thru intercooler is dry. Wondering if there's a hack to clear the goo out from manifold while running or something as I'd rather not disassemble down to cylinders just to blow some cleaner through. But I will if I should...
If this cures her, I'll be sorry for wasting everyone's time. And will owe the car a solid for bitching about her here when she'd done nothing wrong.
11-03-2018, 07:27 PM
#39
Rennlist Member
This is hard to admit - I seem to have refilled with a bit too much oil. Decided to go back to the first thing I noticed wrong which was air plate/plunger not as smooth and drop of plunger slower than before. Pulling it off revealed oil goo sticking up the plunger. All clean now and smooth as silk and plunger drops nice n quick. Cleaned out MAF housing and such, oil seems to have just made it into the elbow area.
I didn't seem to get enough in to make it down to the turbo or up into the IC, but I do have a coating of oil inside the manifold. Not sure if I did that or if it was just there, as the path from the elbow down to turbo and all the way thru intercooler is dry. Wondering if there's a hack to clear the goo out from manifold while running or something as I'd rather not disassemble down to cylinders just to blow some cleaner through. But I will if I should...
If this cures her, I'll be sorry for wasting everyone's time. And will owe the car a solid for bitching about her here when she'd done nothing wrong.
I didn't seem to get enough in to make it down to the turbo or up into the IC, but I do have a coating of oil inside the manifold. Not sure if I did that or if it was just there, as the path from the elbow down to turbo and all the way thru intercooler is dry. Wondering if there's a hack to clear the goo out from manifold while running or something as I'd rather not disassemble down to cylinders just to blow some cleaner through. But I will if I should...
If this cures her, I'll be sorry for wasting everyone's time. And will owe the car a solid for bitching about her here when she'd done nothing wrong.
11-04-2018, 01:59 AM
#40
Rennlist Member
How did you over-fill? .. Did you try to fill while motor was not running? .. just curious on how you "know" that you over-filled,... cuz where you found the oil (manifold), sounds a bit like it may be something else might have allowed it to travel up.
But maybe that is indeed a symptom when the car ultimately has too much oil added the entire system. But if the car was running when you added,.. and you added just a little bit while checking the dipstick all the time,... that shouldn't really happen.
over-filling oil has always been a fear of mine too. With such a large capacity oil-system that Porsche designed into these dry-sump cars, I've always kinda thought that the lesser of two evils would be to be a quart or so low,... verses over capacity.
=Steve
But maybe that is indeed a symptom when the car ultimately has too much oil added the entire system. But if the car was running when you added,.. and you added just a little bit while checking the dipstick all the time,... that shouldn't really happen.
over-filling oil has always been a fear of mine too. With such a large capacity oil-system that Porsche designed into these dry-sump cars, I've always kinda thought that the lesser of two evils would be to be a quart or so low,... verses over capacity.
=Steve
11-04-2018, 03:43 PM
#41
Rennlist Member
There's another reason for that much oil coating the intake tract; it's coming from the turbo.
There are two possible reasons for this:
(1) Damaged or worn shaft shaft seals
(2) The compressor impeller has foreign object damage and is running out of balance. Since it spins at 120k rpm, it tends to act like an oil pump if it's out of balance.
If it's the compressor impeller, it nicely distributes a thin film of oil all through the intake tract. Look at the silicone 90 going from the compressor exducer to the black air pipe coming from the CIS air meter; if there's oil dripping out of it, you found the source of the oil.
Since you've had the intercooler off, you should have seen a lot of oil in the silicone pipe coming from the compressor to the intercooler.
There are two possible reasons for this:
(1) Damaged or worn shaft shaft seals
(2) The compressor impeller has foreign object damage and is running out of balance. Since it spins at 120k rpm, it tends to act like an oil pump if it's out of balance.
If it's the compressor impeller, it nicely distributes a thin film of oil all through the intake tract. Look at the silicone 90 going from the compressor exducer to the black air pipe coming from the CIS air meter; if there's oil dripping out of it, you found the source of the oil.
Since you've had the intercooler off, you should have seen a lot of oil in the silicone pipe coming from the compressor to the intercooler.
11-05-2018, 02:11 PM
#43
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Thread Starter
It wouldn't be the turbo then - the air cleaner box had oil inside, air meter oiled (and the bit causing fuel delivery probs being the plunger/fuel distrib sticky with oil), etc., and no oil down through the turbo. Will know for sure once the new o-ring for fuel dist comes in and I can put it back together.
Last edited by wicks; 11-05-2018 at 03:01 PM.
11-07-2018, 12:03 PM
#44
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Thread Starter
Got FD back on - engine is finally responsive to gas pedal again. BUT, now I get no combustion in cylinder 5. Verified spark. No combusto. Pulled injector, blew clear with air, no change. Put in an old injector (which were all working), no change. Fuel pressure to 5 is present if I loosen fuel line.
Could carb cleaner have damaged o-rings or something in the FD? Heard of people soaking those in cleaner with no problems. I used carb cleaner to clear the oil goo from plunger and blew some through the fuel ports as well, let it dry out 24 hours before reinstalling with a new o-ring air seal. [so many conflicting reports - but on Delorean CIS Parts website he says strongly, do not use carb cleaner it will ruin the FD - PartsKlassik thinks it should be ok unless long soaked]
Did I mention the rotten egg smell? Like a whole dozen, mashed in a corner for a whole year.
Drove around the block - no change. Barely able to get her back up the driveway (steep). I guess one cylinder down makes a lot of drag on rest of motor.
Is there a way to test all the ports on FD without having 6 matching measuring cups? Supposed to drive her up to Big Sur this weekend. May have to take trusty old MFI 911s.
Also my cold start doesn't seem to be functional anymore. Ready to give up.
Thoughts?
Could carb cleaner have damaged o-rings or something in the FD? Heard of people soaking those in cleaner with no problems. I used carb cleaner to clear the oil goo from plunger and blew some through the fuel ports as well, let it dry out 24 hours before reinstalling with a new o-ring air seal. [so many conflicting reports - but on Delorean CIS Parts website he says strongly, do not use carb cleaner it will ruin the FD - PartsKlassik thinks it should be ok unless long soaked]
Did I mention the rotten egg smell? Like a whole dozen, mashed in a corner for a whole year.
Drove around the block - no change. Barely able to get her back up the driveway (steep). I guess one cylinder down makes a lot of drag on rest of motor.
Is there a way to test all the ports on FD without having 6 matching measuring cups?
Supposed to drive her up to Big Sur this weekend. May have to take trusty old MFI 911s.Also my cold start doesn't seem to be functional anymore. Ready to give up.
Thoughts?
Last edited by wicks; 11-07-2018 at 05:18 PM.
11-08-2018, 01:42 AM
#45
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Thread Starter
...The membrane material (a bit hangs out the side and is strong) and the o-rings on the regulator seem to be unaffected by the carb cleaner, so I'm thinking the FD is maybe OK. Want to get it on a proper test rig...anyone in the LA area have one? There don't appear to be filter screens under the banjos, are there supposed to be on a 145 unit? Was gonna pull those.
Any other ideas why cylinder 5 would be failing to fire? Air, fuel, spark, air fuel spark...
Any other ideas why cylinder 5 would be failing to fire? Air, fuel, spark, air fuel spark...