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-   -   Project Avocado - 1986 Moss Green 911 Rebuild (http://forums.pelicanparts.com/porsche-911-technical-forum/1025818-project-avocado-1986-moss-green-911-rebuild.html)

Gabe. 08-07-2020 10:27 AM

As I mentioned in my last post, I was ready for a spirited drive on Sunday morning (last Sunday).

There was a bit of traffic along PCH but once I got up into the canyons things started opening up. About halfway up Topanga Canyon the car had a light misfire. By the end of Old Topanga Canyon road I stopped at the side of the road to see what was going on. It would have an occasional pop at idle (video below) but wasn't sounding great and wouldn't rev up on partial throttle. I was able to limp it home to start diving into diagnosis.

This is the popping I was talking about:

<iframe width="560" height="315" src="https://www.youtube.com/embed/UNySnK0XJkY" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Here's what I've done since Sunday:
  • Compression Test. All came back the same as they were before. Cylinder #2 hasn't had the rings seat yet, it's only been driven 75 miles.
  • Leakdown test, all the same as before. Results are positive and there are no issues here other than cylinder #2 that needs the rings to be broken in.
  • Checked ignition timing, my Tooth #1 Angle was off 10 degrees. When I first got the car done it wasn't a reliable trigger, this time I'm more confident with it. It's set at 60 degrees and with the timing fixed to zero it's firing at the TDC mark. I've also adjusted most of the ignition map to compensate for the change, it was really conservative before (2/5 degrees timing advance at idle). This could definitely be an area of concern but with the car having been driving fine before, I'm not sure how important this is.
  • Double checked mechanical timing. Yes, I took the back of the engine apart and spilled oil all over my garage floor again. DRC specs at 3.0-3.2mm for my cams with .004" valve clearance at TDC. It's at 0.120" which is about 3.05mm. It's the same for both left and right side cams.
  • Checked valve springs, retainers, rocker arms, and while I was in there I adjusted all the valve clearances and double-checked head stud torque.
  • New spark plugs (NGK BCPR7es gapped to .035") and I also tested out another set of OEM Audi R8 ignition coils I hadn't used because they were too long.
  • Confirmed fuel pressure is steady. You can see the gauge in the videos and it's stable.
  • ITBs are synced and pulling ~6 on my synchrometer.
  • Hooked up my mity vac (it's the only vacuum gauge I have) and it was ~5 in hg at idle, which seems low but I have no idea what it should be or was before on a car with ITBs.

Here is a vid of how it's running now:

<iframe width="560" height="315" src="https://www.youtube.com/embed/Cd-5MB2XJug" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Electrically there are seven sensors that contribute to how the ecu makes the car run
  • Crank Sensor
  • Cam Sensor (which is hooked up but not yet being used for full sequential)
  • Intake Air Temp sensor
  • Throttle Position sensor
  • Cylinder Head Temp sensor
  • Wideband O2 sensor. AEM sensor running CAN so it's getting a direct signal into the ECU.
  • Manifold Absolute Pressure sensor. I'm running the MAP sensor that's internal to my MS3 Pro. I'm running an Alpha N tune which uses throttle position to work it's way through the VE table and the MAP sensor is a secondary sensor.

All the sensors are operating as they should according to the readouts I see in Tunerstudio.

The car starts if you push the gas pedal a bit (which I didn't need to do before) and is idling really low ~400-500 rpm. The revs aren't picking up speed from idle like it was before which really makes it undrivable. I can slowly bring the revs up and once it's over 2000-2500 rpm it seems to rev normally above that. I can hammer the throttle to 50-100% at idle and the engine doesn't really do anything to respond (it's still trying to idle, too much air will make it die unless I do it slowly to get the revs up past 2000 rpm).

It seems like it could have a pretty large vacuum leak somewhere but with all my poking around I haven't found any. I've also sprayed starting fluid around all the common areas and it's not making any increase to idle.

After doing a full health check, I'm pretty stumped and would love any ideas of what to check next from the Pelican brain trust. My thought is to take the ITBs off the heads and check the intake manifold spacers and gaskets but after having sprayed starting fluid around there with no change I'm not sure I'll find anything.

Thank you for all your help!

Mixed76 08-07-2020 11:09 AM

Sounds like spark timing or tuning.

And, glad to hear your back on the road, even if it's not quite right yet.

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Gabe. 08-07-2020 01:38 PM

Quote:

Originally Posted by Mixed76 (Post 10977335)
Sounds like spark timing or tuning.

And, glad to hear your back on the road, even if it's not quite right yet.

Sent from my Nokia 7.1 using Tapatalk

I just don't understand how it can run perfect on Saturday and then not on Sunday. The only difference between the two driving sessions was being in traffic for a bit before getting up in the canyons on Sunday.

It's not running great when it's cold or at throttle tip in when it's warmed up. It used to have instant throttle response off of idle.

Anyone have any ideas what could cause that?

Here's another vid that I just took. I may go drive it around the block and grab some footage too.

<iframe width="560" height="315" src="https://www.youtube.com/embed/N04VS7GJqu0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Mixed76 08-07-2020 02:09 PM

Me either. A sensor should be acting up if the tuning didn't change.

Sent from my Nokia 7.1 using Tapatalk

Mr. Merk 08-10-2020 05:34 AM

I didn't have any internet while camping this weekend. I saw on IG that you had it ripping but didn't get to see your story on what was the wrong. In for an update!

Gabe. 08-10-2020 07:04 AM

Morning all,

I ended up posting a separate thread to get some more traction on the issue: http://forums.pelicanparts.com/porsche-911-technical-forum/1069595-im-stumped-efi-itbs-have-no-throttle-response-help.html

the TLDR:
  • Someone told me to spray water on the headers to make sure all the cylinders were firing...
  • They weren't despite test mode on all the injectors and spark plugs working.
  • That narrowed down the issue to that side of the engine, it wasn't fuel, so I checked spark.
  • I pulled a plug out and grounded it to a bolt, fired up test mode and the spark was really weak.
  • Checked continuity on all the ignition coil wiring, checked voltage, and found I had an issue between the power pin and one of the two grounds on the ignition coil plugs.
  • The ground with poor voltage terminates at the cylinder head and I found that there must have been oil in the bolt hole which was leading to an intermittent ground.
  • Cleaned it out with brake clean and compressed air and it fired right up!

That meant that all I really did last week was confirm that everything was healthy, never a bad thing but I had just put fresh gaskets in (last week) and now I'm getting weeping in a few spots since I had to pull valve and cam housing covers again.

Since then I've been playing around with the tuning some more. With my "tooth #1 angle" being ten degrees off I've had to rework my ignition map. Ultimately I'd like to get it professionally tuned so I know it's both done right and we have an idea of the power it's making.

I'm also praying that I'm able to get the rings on cylinder #2 seated, so far there is still a bit of blowby but it only has ~125 miles on it.

But yes... My canyon run yesterday was f-in AWESOME. This is the best that the avocado has run since I got it put back together. We also had a going away Porsche meetup at The Motoring Club for my friend Sid and it was really great to be able to bring my car there. I forgot to take pics but had a few friends that did, this seems to be the most popular view:

http://forums.pelicanparts.com/uploa...1597071793.JPG

chrisbalich 08-11-2020 05:13 AM

There is no better feeling than tearing something completely apart fearing the worst and finding something silly causing all your grief.
Glad you're back on the road. I reckon you and I are both overdue for some rolling footage (with audio).

yeezus 08-11-2020 07:14 AM

Hey Gabe, nice to meet you at the MC on Sunday (we were introduced by Matt/nomadicginger). Great to see the avocado in person! It's kind of funny how something as small as a little bit of oil where it shouldn't be can throw everything out of whack.

Gabe. 08-11-2020 10:34 AM

Quote:

Originally Posted by chrisbalich (Post 10981097)
There is no better feeling than tearing something completely apart fearing the worst and finding something silly causing all your grief.
Glad you're back on the road. I reckon you and I are both overdue for some rolling footage (with audio).

Haha, I know. Glad it was something simple. My latest worry is the rings on cylinder #2 breaking in. I used the Driven GP-1 20w-50 oil I had and I'm worried it's too slippery. I ordered some GP-1 30w break-in oil in hopes that it helps. The compression test and leakdown have only mildly changed in the ~125 miles I've driven it so far.

I posted an audio clip to my instagram, it was filmed from my phone in my pocket so the audio quality isn't world-class but it really isn't all that bad either. More videos to come for sure!

Quote:

Originally Posted by yeezus (Post 10981251)
Hey Gabe, nice to meet you at the MC on Sunday (we were introduced by Matt/nomadicginger). Great to see the avocado in person! It's kind of funny how something as small as a little bit of oil where it shouldn't be can throw everything out of whack.

Yea! Nice to meet you too. It can sometimes take forever to find the smallest of problems. I'm glad it was simple.

Gabe. 08-19-2020 11:48 AM

It's time for another update post!

Over the last week I've been driving the car as much as possible to get cylinder #2 to break in prior to.... wait for it... a dyno tuning session at Ed Pink! That's going down tomorrow morning, I'll be sure to share vids and results. I'm pretty excited for it. For those of you that may be unaware, they're the crew that builds the 12v engines for the singer 911s. They recently got a dynojet dyno and have opened up their shop for tuning. They have experience with Megasquirt and Tunerstudio and I'm really hoping we can get this thing dialed. Great startup, idle, part throttle, and full throttle are what I'm looking for.

In terms of engine health, cylinder #2 is giving me some headaches and I'm not sure if more miles will "fix" what may be parts that need to be replaced. Namely the cylinder that was deglazed/honed, whatever debris got into the cylinder may have gotten it out of round/out of spec in that spot.

The whole engine has about 1,100 miles on it, 450 are with the work we've done to cylinder #2. 150/450 of those miles were with 20w50 GP1 (brad penn) and the next 300/450 were with GP1 30w break-in oil. I'm not sure if it's the break-in oil or additional mileage that have helped, but we've gone from 70 psi to 90 psi cold up to as much as 110 psi hot. That is not in line with the rest of the cylinders yet so I will likely pull the engine back apart again when I find a replacement cylinder.

I did a full health check on the engine yesterday and here's where we stand on compression:
  • Cylinder 1: 170psi
  • Cylinder 2: 90psi
  • Cylinder 3: 170 psi
  • Cylinder 4: 180 psi
  • Cylinder 5: 170 psi
  • Cylinder 6: 170 psi

I also regapped all the plugs to .035" and I'm going to swap the oil back over to 20w-50.

It's about as good as it's going to get prior to our session tomorrow morning.

In terms of other news, I found a sweet deal on a local 991 GT3 muffler setup so I'll be swapping from the Billy Boat muffler over to the GT3 with cutouts. Looking forward to some fab work to make that happen!


http://forums.pelicanparts.com/uploa...1597866077.jpg


Part of the reason this car went together so "quick" is that I've been able to order and receive parts in the same day from BMA Parts up in Glendale, CA. They just held their first "The Sunday Club" cars and coffee this Sunday so of course I had to go support them. It was also fun to show them what I've actually been working on as I usually show up in my wife's Honda.

Here are some AMAZING (imo) shots that were taken by Kenny Torres, @blacklistspecial on Instagram. This car being dark green makes it really difficult to capture the true color. He was somehow able to do it! Enjoy!

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

http://forums.pelicanparts.com/uploa...1597866077.jpg

Mixed76 08-19-2020 11:57 AM

Quote:

Originally Posted by Gabe. (Post 10992081)
It's time for another update post!



Over the last week I've been driving the car as much as possible to get cylinder #2 to break in prior to.... wait for it... a dyno tuning session at Ed Pink! That's going down tomorrow morning, I'll be sure to share vids and results. I'm pretty excited for it. For those of you that may be unaware, they're the crew that builds the 12v engines for the singer 911s. They recently got a dynojet dyno and have opened up their shop for tuning. They have experience with Megasquirt and Tunerstudio and I'm really hoping we can get this thing dialed. Great startup, idle, part throttle, and full throttle are what I'm looking for.



In terms of engine health, cylinder #2 is giving me some headaches and I'm not sure if more miles will "fix" what may be parts that need to be replaced. Namely the cylinder that was deglazed/honed, whatever debris got into the cylinder may have gotten it out of round/out of spec in that spot.



The whole engine has about 1,100 miles on it, 450 are with the work we've done to cylinder #2. 150/450 of those miles were with 20w50 GP1 (brad penn) and the next 300/450 were with GP1 30w break-in oil. I'm not sure if it's the break-in oil or additional mileage that have helped, but we've gone from 70 psi to 90 psi cold up to as much as 110 psi hot. That is not in line with the rest of the cylinders yet so I will likely pull the engine back apart again when I find a replacement cylinder.



I did a full health check on the engine yesterday and here's where we stand on compression:
  • Cylinder 1: 170psi
  • Cylinder 2: 90psi
  • Cylinder 3: 170 psi
  • Cylinder 4: 180 psi
  • Cylinder 5: 170 psi
  • Cylinder 6: 170 psi



I also regapped all the plugs to .035" and I'm going to swap the oil back over to 20w-50.



It's about as good as it's going to get prior to our session tomorrow morning.



In terms of other news, I found a sweet deal on a local 991 GT3 muffler setup so I'll be swapping from the Billy Boat muffler over to the GT3 with cutouts. Looking forward to some fab work to make that happen!





http://forums.pelicanparts.com/uploa...1597866077.jpg





Part of the reason this car went together so "quick" is that I've been able to order and receive parts in the same day from BMA Parts up in Glendale, CA. They just held their first "The Sunday Club" cars and coffee this Sunday so of course I had to go support them. It was also fun to show them what I've actually been working on as I usually show up in my wife's Honda.



Here are some AMAZING (imo) shots that were taken by Kenny Torres, @blacklistspecial on Instagram. This car being dark green makes it really difficult to capture the true color. He was somehow able to do it! Enjoy!



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg



http://forums.pelicanparts.com/uploa...1597866077.jpg

Is that a Ti or stainless muffler? Have you weighed it?

Car looks great! Sad to hear about the compression. Based on your pictures I would suspect ring land not flat, but you may be on to something with cylinder out of round. Have you got any way to confirm blow by/ gas circulation from crankcase to intake?

Sent from my Nokia 7.1 using Tapatalk

Gabe. 08-19-2020 12:29 PM

It's a stainless muffler. I haven't weighed it but the BBE muffler is heavy AF. Even if it's a wash in the weight department I gain the ability to have the car quiet when I don't want it to be loud.

Yea, I suppose ringlands could be an issue too. I'll replace the piston at the same time I find a cylinder. What I should really do is go with a 3.4 and then I can use these in the other engine I have. Hmmmm...

In terms of blowby confirmation, I do have a a leakdown tester and the leakdown on cylinder #2 is horrible. I'm not sure there is a way to check if it's the ringlands vs a wonky cylinder but pressure is definitely leaking out the rings vs intake/exhaust valves. Also, being ITB there really isn't a way to reroute the blowby back into the engine, the oil tank is capped off with an ITG filter.

LJ851 08-19-2020 12:40 PM

Quote:

Originally Posted by Gabe. (Post 10977064)

The piston had the roughness sanded down, ring lands filed/smoothed, and ready for new rings. The chip was sanded down more than this but I forgot to take a final picture of it:

http://forums.pelicanparts.com/uploa...1596811110.jpg



If this is the piston that is in the number 2 hole, the problem is 100% the ring lands and needs to be replaced as i mentioned before.

Gabe. 08-19-2020 12:57 PM

It is, I just ordered the new piston. Won't ship until early September.

I do appreciate your advice, I didn't initially order the piston due to the timeframe it takes to get it but now that the car runs/drives it's no big deal.

LJ851 08-19-2020 01:25 PM

Quote:

Originally Posted by Gabe. (Post 10992197)
It is, I just ordered the new piston. Won't ship until early September.

I do appreciate your advice, I didn't initially order the piston due to the timeframe it takes to get it but now that the car runs/drives it's no big deal.


I understand.

Its shocking how tight the flatness tolerance for a ring land on a high quality piston. For proper sealing, the top ring land is like 3-5 microns variance around the entire ring land !

Tremelune 08-19-2020 05:03 PM

Quote:

Originally Posted by Gabe. (Post 10992081)
I've been able to order and receive parts in the same day from BMA Parts up in Glendale, CA.

Whoa, say what now? What kinda parts we talkin'?

Bigtoe32067 08-19-2020 08:24 PM

What’s the deal with long hood project parked next to it. Hard to hide it in that open garage.
It looks completely amazing with those gold 15” mini lites. I wasn’t sold on the green until you put the gold wheels on it and now it’s one of my faves.
Wish I lived closer so I could see it.
Please don’t feel discouraged at times if you don’t get a lot of comments or feedback on your posts because some of us are hugely interested but just lurk a bit. There are tons of us that follow very closely but just don’t comment a lot so please keep on with the thread.
Good luck and keep up the good work.
Tony

chrisbalich 08-20-2020 04:52 AM

Quote:

Originally Posted by Gabe. (Post 10992081)

:drool:

Gabe. 08-20-2020 03:30 PM

Quote:

Originally Posted by LJ851 (Post 10992245)
I understand.

Its shocking how tight the flatness tolerance for a ring land on a high quality piston. For proper sealing, the top ring land is like 3-5 microns variance around the entire ring land !

Yea, that is pretty wild. I'd like to find another cylinder to install at the same time and am hoping that isn't too hard to do.

Quote:

Originally Posted by Tremelune (Post 10992555)
Whoa, say what now? What kinda parts we talkin'?

Primarily maintenance and OE parts but they also have fluids and tools. Pretty much anything that comes from the large parts houses. Good group of enthusiasts too. They're about equidistant with pelicanparts from me but the same day pickup has generally made it my preferred place if I need something that quickly.

Quote:

Originally Posted by Bigtoe32067 (Post 10992724)
Whatís the deal with long hood project parked next to it. Hard to hide it in that open garage.
It looks completely amazing with those gold 15Ē mini lites. I wasnít sold on the green until you put the gold wheels on it and now itís one of my faves.
Wish I lived closer so I could see it.
Please donít feel discouraged at times if you donít get a lot of comments or feedback on your posts because some of us are hugely interested but just lurk a bit. There are tons of us that follow very closely but just donít comment a lot so please keep on with the thread.
Good luck and keep up the good work.
Tony

Haha, yea at some point I stopped caring about keeping that car a "secret", too difficult to keep it out of the pictures and videos. I'll probably start working on it soon now that I'm caught up on the Avocado.

It's a 1973 911 T that was an RSR project that was started and never finished. I picked it up from David W on the forums. My tentative plan is to put some Carrera RS fender flares on it, paint it (thinking 1978/79 911 SC Olive Green), swap the engine from this car, and never have to worry about smog again.

The green is really difficult to photograph which is why seeing it in person has been so polarizing for many. Kenny did a fantastic job in those last pics I posted. The black wheels are kinda the same deal, look awesome in person, not so much in pictures because they disappear.

Thank you for following along and feel free to comment once in a while :p

Quote:

Originally Posted by chrisbalich (Post 10992902)
:drool:

SO GOOD.

Gabe. 08-20-2020 04:35 PM

This next post deserves to be at the top of the page...


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