I've got the Big 3 but no start

[rbuswell]

I posted the below request for info about wire order on the distributor cap and suggestions of what might be wrong to an older thread but no one responded. It could be that it didn't generate much interest because the original post is so old. Or maybe everyone is at work.

http://forums.pelicanparts.com/10481242-post4.html

It appears that I have fuel, air and spark (the Big Three as my dearly departed friend, Grady Clay, used to tell me) but the engine won't start. My belief is that if you have those elements, the ECU is probably working OK. I don't believe there's any restriction that the intake module could execute to get in the way of airflow.

I'm looking for a troubleshooting list of what to check when the Big Three appears to be present but the car won't start. Thanks for all your help.

[Jfrahm]

Check your assumptions.
Is it wired right? Not 180 degrees off?
Distributor rotor turning?
Spark capable of jumping 10mm?
Starting fluid?
What do the plugs look like?

[kolll]

your friend was wrong
the big 3 is - fuel, spark, timing

[rbuswell]

Originally Posted by kolll

your friend was wrong
the big 3 is - fuel, spark, timing

Good catch. Timing is crucial. That's why I wanted someone to confirm that the distributor cap wiring diagram is the same for a 924S and a 944. No one has yet. Typical Pelican.



It could be Grady called it the Big Four. He died about five years ago so I may have forgotten how he said it. Obviously you don't get combustion without oxygen.


BTW, since you don't know who Grady was, you may want to put out a request to find out more about him from the Pelican faithful. Or you may just try searching his name. Amazing how quickly people forget.

[rbuswell]

Originally Posted by Jfrahm

Check your assumptions.
Is it wired right? Not 180 degrees off? This was why I wanted confirmation of the proper wiring for a 924S versus a 944. Still no answer on that one. The cap can only go on one way.
Distributor rotor turning? If it isn't turning you would get no spark.
Spark capable of jumping 10mm? It was a very bright spark when I tested them to a ground. Not sure about 10mm. That's a pretty big gap. Is there a reason it should jump that big a gap?
Starting fluid? Haven't tried that one yet.
What do the plugs look like? Plugs looked very good. Light beige like you'd hope to see.

Thanks for the questions. Answers in red above.

[djnolan]

Is the AFM connected? How do you know you have fuel?

Also spark across a normal sparkplug gap should be blue or white, not orange or yellow so check it with a plug jumpered to ground.

If you're unsure of the timing there is a timing mark on the flywheel and another one on the cam pulley/housing to align and make sure the rotor is pointed at no 1 cylinder. (assuming you haven't changed the timing belt or something)

Have you checked out Clark's? Troubleshooting - Engine

[kolll]

BTW, since you don't know who Grady was, you may want to put out a request to find out more about him from the Pelican faithful. Or you may just try searching his name. Amazing how quickly people forget.

no hard feelings - i'm new to porsche and yes- i didn't know who Grady was(thanks for pointing, by the way- very interesting person)
there is no catch on timing - you have to be 100% sure about correct timing
1-st - you have to put the car at TDC.
Take off the cap and the rotor will be pointing to #1 lead, that is your starting point.
Put the cap back on, and make sure the lead for # 1 is above the rotor,
then clockwise from top the order is- 1-3-4-2

Obviously you don't get combustion without oxygen

and now the catch
if you have supply of pure oxygen- you don't need fuel

It appears that I have fuel, air and spark

how do you know that you have air??
obviously you always have air, BUT- does your DME know that there is the air in the intake???? - check AFM (after you 100% sure about timing)

[rbuswell]

Originally Posted by djnolan

Is the AFM connected? How do you know you have fuel?

Also spark across a normal sparkplug gap should be blue or white, not orange or yellow so check it with a plug jumpered to ground.

If you're unsure of the timing there is a timing mark on the flywheel and another one on the cam pulley/housing to align and make sure the rotor is pointed at no 1 cylinder. (assuming you haven't changed the timing belt or something)

Have you checked out Clark's? Troubleshooting - Engine

I wish I could do more than provide the link to the other post I wrote on the legacy thread about the spark plug wires. Maybe I should copy and paste everything from the other post here too. The questions point to folks not seeing what I wrote there. I'd really like to confirm that I wired the distributor cap correctly. Why I can't find a reference online re: how it might be different for a 924S than a 944 is frustrating.

1. I did take the AFM/MAP/airbox unit off to have the alternator rebuilt. There were a couple fastener spots on the airbox I had to rebuild as well. I plugged the harness back in and it seemed OK. If there's another harness plug I'm missing, I may need your help. Nothing is dangling down that I can see.
2. The plugs were wet with fuel when I took them out. Injectors have been rebuilt and calibrated by RC Engineering. Those guys are top notch BTW.
3. Plugs fire bright white when grounded. All four plugs have the same bright white result.
4. As noted in the other post, I did replace the timing belt. The car is a rust free rehab project for which the water pump had frozen. I used the Porsche shop manual, Clark's write up (including his idea to confirm timing with a dowel in the #1 cylinder), got one-on-one help from Bruce Arnn on a couple other issues including a frozen tensioner. I'm also YouTube certified . The timing was spot on initially looking at all the spots you mentioned which means the frozen water pump didn't mess it up. I suppose it could be 180 degrees off but for it to fall exactly at 180 degrees off seems very unlikely. I don't think I'd have uniform compression even though it is low. The head should be thrashed. My thought is that the car sat for over two years. Compression should come back up after it's run. All this is what I expected given how the PO said the car behaved before he parked it. The PO wasn't much of a car guy but he seemed to be honest about stuff. Everything else he told me has panned out with the car.
5. I thought I had all of Clark's stuff downloaded but I don't think I've seen this link before.

Regardless, I really appreciate you guys!

[rbuswell]

Originally Posted by kolll

no hard feelings - i'm new to porsche and yes- i didn't know who Grady was(thanks for pointing, by the way- very interesting person)
there is no catch on timing - you have to be 100% sure about correct timing
1-st - you have to put the car at TDC.
Take off the cap and the rotor will be pointing to #1 lead, that is your starting point.
Put the cap back on, and make sure the lead for # 1 is above the rotor,
then clockwise from top the order is- 1-3-4-2


and now the catch
if you have supply of pure oxygen- you don't need fuel

how do you know that you have air??
obviously you always have air, BUT- does your DME know that there is the air in the intake???? - check AFM (after you 100% sure about timing)

1. In a few days, it will be the five year anniversary that Grady died. I was closer to him than my own brother. I tagged along to so many events and opportunities and met so many important Porsche people because of him. He told me things about his life I don't think he told anyone else. I was asked to speak at his memorial service which was a big honor. I'm probably a little touchy about people forgetting about him. He was a one in a million titan of the air-cooled and racing world. Sorry I was a little snarky about that.
2. Re: timing see what I wrote djnolan above. I will try again but I'm really confident that I have this right. For as long as I've turned it over and the car ran when the PO had the water pump freeze, I don't think I'd have compression at all. The valves would be like pretzels. You did answer the spark plug wiring question except for which position is #1. I assume it is the 4 o'clock position on the cap. If it is and there's no difference between a 924S and a 944, I have the cap wired correctly.
3. Your idea on the AFM was my suspicion too. I also thought about the ECU itself but you wouldn't think I'd be getting fuel or spark if that was fried. Also, what would have happened to the AFM to cause it to stop running now? The car ran fine before the water pump froze according to the PO. The AFM just sat quietly on a table until I installed it again. If you have a reference to point me to on how to check the AFM, I'm all ears.

[rbuswell]

Here's the prior post I referenced again if you missed it in my first post here. Pelican doesn't provide a way to display pictures in the body of the post:

http://forums.pelicanparts.com/10481242-post4.html

[944 Ecology]

You mention in your old post that compression was low, but uniform. How low... that could be your problem.

These are my three essentials: fuel injected into the cylinder, compression, ignition timing.

[rbuswell]

Originally Posted by 944 Ecology

You mention in your old post that compression was low, but uniform. How low... that could be your problem.

These are my three essentials: fuel injected into the cylinder, compression, ignition timing.

I just received a PM from a fellow with a 924S who had the same experiences as me (all the right stuff to start but the car had sat for a few years). He added some oil through the spark plug holes and his car started immediately. He had heard the rings don't seat after a 944 engine sits for awhile.

I had intuitively done the same thing before doing the compression check. I had to turn the engine over solo without watching the compression gauge so I'm not really sure if the compression had reached its maximum but they were all coming in at around 100 PSI. What I'm seeing online is 135 PSI is a good target.

It's been a few days since I tested compression. Does it make sense to do the top end oil treatment again?

BTW, I think we're up to the Big 5. Ha ha.

[Jfrahm]

Distributor rotor turning? If it isn't turning you would get no spark.
No you usually get sparks but only on one lead.

Spark capable of jumping 10mm? It was a very bright spark when I tested them to a ground. Not sure about 10mm. That's a pretty big gap. Is there a reason it should jump that big a gap?
Bright does not really tell you what you need to know, I have seen before a decent looking spark on a 1mm gap but in the head, under compression, no spark. The 10x or so more air in the head under compression is why you want to see at least 10mm of spark jump through regular pressurized air. Expanding the gap simulates the difficulty of sparking through 180psi air.


Starting fluid? Haven't tried that one yet.
It's an interesting test, and easy as you can spray into the FPR vacuum line or whatever's handy.

[rbuswell]

Originally Posted by Jfrahm

Distributor rotor turning? If it isn't turning you would get no spark.
No you usually get sparks but only on one lead.

Spark capable of jumping 10mm? It was a very bright spark when I tested them to a ground. Not sure about 10mm. That's a pretty big gap. Is there a reason it should jump that big a gap?
Bright does not really tell you what you need to know, I have seen before a decent looking spark on a 1mm gap but in the head, under compression, no spark. The 10x or so more air in the head under compression is why you want to see at least 10mm of spark jump through regular pressurized air. Expanding the gap simulates the difficulty of sparking through 180psi air.


Starting fluid? Haven't tried that one yet.
It's an interesting test, and easy as you can spray into the FPR vacuum line or whatever's handy.

1. You may not have seen the actual post to the other thread or you saw it before I amended it to say I tested all four plugs to a ground. I have to work around my wife's schedule since she turns the key for me. The rotor had to be turning since all four plugs fired to the ground. I'm guessing here but if the rotor stopped at the spot where it makes a connection, the spark would only last one pulse since the coil would be drained and if the rotor wasn't turning while the engine is turning over, the timing belt would need to be missing.
2. So you're saying I can hold the plug 10 MM away from the ground and the spark will jump that gap? That's good to know and kind of scary too. Sort of Nikola Tesla-like. You obviously can't spread the electrode gap 10 MM. Maybe you mean to speak in fractions of a millimeter.
3. Re: starting fluid I don't own the stuff since it kind of scares me too. Is there a brand you suggest?

[Jfrahm]

1 - Actually there is a transistor (points in the old days) that allows the coil to charge regardless of the rotor position, if the timing belt is blown it'll usually just spark one plug over and over again, whichever is nearest the stationary rotor tip.

2 - No, 10mm is important to simulate the power it takes to fire the plug under high-pressure inside the head. That's why spark checkers exist! You can buy a spark checker or make something, rig something up. Cut the ground prong off an old plug and rig it 10mm away from a ground point. It's not safe to hold in your hand when doing this.

3 - Never concerned myself with starting fluid brands, they are all the same to me so far. You can also use some gasoline if you like. They sell "flavor injector" marinade syringes at the dollar store (for a dollar) which would also be good for squirting some gas into the intake or vacuum system.

[rbuswell]

I rechecked the timing and the mark on the cam housing in the peep hole matched up with the #1 rotor station (as good as one can tell with this rather crude system). I also looked into the #1 plug hole and the piston looked like it was at TDC. I couldn't find my dowel that Clark recommends as another check.

I checked the compression again and it was better:

#1 = 112 PSI
#2 = 112 PSI
#3 = 110 PSI
#4 = 112 PSI

While checking the compression, the tank-to-filter hose connection to my new gas filter started to leak a lot. The hose to the gas line also leaked but not much. Neither had leaked in prior engine tries so I don't know why it leaked this time. I tightened the connections and it leaked a lot less but I will replace the hoses ASAP.

I also wondered if I wasn't pushing the spark plug wires into the head far enough so I used a little plastic upholstery tool to press them in more.

I decided "what the hell" and tried starting it one more time. It started instantly and continued to run but it sounded like a threshing machine. It smoothed out a little but it still made a lot of noise. The oil pressure light blinked but it showed over 4 bars on the oil gauge. I only let it run about 10-15 seconds. I started it three times. It started fast all three times without evidence that it wanted to die. It also dropped idle a little in that short of time. Other than all the racket, it seems to be doing what you'd expect.

My wife took a video of it running with her iPhone but we have to wait for my daughter to get home to upload it to YouTube to show you guys since neither of us have done that before and we need to use higher bandwidth since videos are big files.

Here are my questions:

1. If it actually is out of timing would it run or would it just trash the valves and quit? The noises sound mechanical but it keeps running and doesn't act like it wants to quit at all. It just sounds awful.
2. With uniform compression, does it seem likely that the valves were already trashed or that I just buggered them?
3. Any thoughts on the oil pressure light blinking but still having very good oil pressure at the gauge?
4. Even though there was no evidence of gasoline leakage the first time we tried, could the possible low fuel pressure from the hoses have been part of the no start problem since it started after tightening them?
5. Are the plug wires so particular that pressing them in a little more may have been part of the success?
6. Could the rings have finally seated enough to bump the compression to a range that it needed?

Regardless whether this is good news or not, I appreciate that you guys have stuck this out with me. I really appreciate it.

[djnolan]

The noise may be the lifters after sitting a long time.

But DON'T try to start it again without fixing the gas leak first. One spark and it could all be over...

You can jumper the fuel pump at the DME relay to leak test without starting it, and disconnect the coil so it can't throw any sparks...

[kolll]

Are the plug wires so particular that pressing them in a little more may have been part of the success?

not really , but possible
most likely -

Could the rings have finally seated enough to bump the compression to a range that it needed?

hard to tell about noise, but as djnolan said - looks like lifters, specially as you stated about oil pressure light
maybe video tells more

[rbuswell]

Originally Posted by djnolan

The noise may be the lifters after sitting a long time.

But DON'T try to start it again without fixing the gas leak first. One spark and it could all be over...

You can jumper the fuel pump at the DME relay to leak test without starting it, and disconnect the coil so it can't throw any sparks...

Originally Posted by kolll

not really , but possible
most likely -
hard to tell about noise, but as djnolan said - looks like lifters, specially as you stated about oil pressure light
maybe video tells more

Working on sourcing the hoses. Lifters sound like the right guess ... what's the fix if they are? Running it and they will come around or pulling and rebuilding the head?


Thanks again for everyone's help.

[rbuswell]

Here's the close-up video on YouTube: https://youtu.be/6rn8PDEfYQY

Here is the initial start-up video. You can hear my lovely wife go YooHoo! because it started. Meanwhile I'm having a cow given the noises I didn't want to hear: https://youtu.be/5jiBMLHjV7M

There is also a lot of other background noise with a bad muffler that is something I didn't want to change out until I can drive the car to a shop who can do the welding.