Two weeks, still can't get my car to run...

dotorg · 05-08-2005, 10:55 AM

I'm running out of things to try.

The backstory:

My car (68L with the stock 2.0L engine but with the S cams) was running far too well, so I decided it would be best to make a big mess of it and install the Crane XR700 I bought from Pelican two years ago.

I had issues getting it installed in the distributor -- the pivot point for the points mechanism hit the plastic wheel, so I had to sand it down until it cleared.

I got the rest of the XR700 installed. It took a few tries getting everything aligned right enough to get the car timed. I think at first I had the rotor misaligned in the distributor, and it was slightly off the contact. Adjusted it again, and triple checked everything, and I'm 99.5% sure everything is timed and aligned correctly, and every indication is the XR700 is working (the diagnostic LED flashes while the engine is running).

So here's the problem: the car starts most of the time, and runs for a few seconds, then the idle speed starts to drop until it starts to stumble and stalls. Giving it a little gas seems to hasten its demise, although a good goosing of the gas pedal wakes it up briefly.

As I've said I've triple checked everything. I've got a convoluted ignition involving the stock coil firing into a Jacobs tach adapter, into a Jacobs ignition firing a Jacobs coil which actually feeds the distributor. While overly complicated, its worked perfectly for two years. Bypassing it by using the stock coil wire to send the spark directly to the cap doesn't change anything, so I don't think the problem is there.

This morning I checked the fuel flow at the feed line to the carbeurators. Fuel is flowing fine, so its not the pump or filters.

My girlfriend, who was behind the car while I was starting it said she thought the exhaust was a lot more noticable, and I thought it had a slight blue tinge to it (gak!). I pulled the plugs, and they're a mess:

I'm baffled and not sure what to check next. I'm not sure if the plugs are like that because of the actual problem, or just because a dozen attempts to start it when it didn't run well just dirtied them.

Thoughts?

yelcab1 · 05-08-2005, 11:00 AM

I know you said you got the car timed, but did you check the timing with a light? how did you static time it?

Wayne 962 · Wayne 962's Garage

Those plugs tell a story.

First of all there appears to be a lot of soot on the white ceramic part of the plug - that's very odd. Is that just dirt from your tool? The ceramic part should always be clean, unless something is really, really wrong.

Secondly, your entire thread of the spark plug appears to be covered in black oil or soot? Frankly, I'm not quite sure how that can even happen. I suppose that if your plug is not tight in the hole, and you have a bunch of oil in the piston/cylinder then it might blow back up into the threads (might explain the black soot on the ceramic too). But complete coverage like you have in the photo - that looks like it's been dipped in oil and then placed in a toaster oven.

Are these new plugs? What do the other plugs look like, do they all look the same? When inspecting plugs you want to compare all the cylinders to each other. If they all look the same, then your problem is with the system. If one stands out, then you may have a problem with a particular cylinder.

Maybe the photo is off too, but it looks like there may be a crack in the ceramic portion of your plug? Near the 'B'?

-Wayne

dotorg · 05-08-2005, 02:30 PM

I checked the plugs pretty carefully, there wasn't a crack, its probably an artifact of the photo being shrunk or something.

The threads were oily. Your guess is as good (well, quite a bit better) than mine why... I pulled the #2 and #1 plugs and both were like that. Totally crusted with carbon. The exposed parts of the plug were dry, not oily. The threads on both were oily. At first I thought maybe there was oil pooled outside the head, and I dragged the end of it through it, but the tips were not oily, so whatever got the threads oily happened with them in place. They were snug.

The white ceramic part outside was COVERED in soot. It was wiping off on my hand, so I was careful to get a picture with some of it there, since I thought it was so bizarre. Its possible its from the tool, but unlikely, as the tool seemed clean when I was looking at it. (I hadn't used the factory plug tool before, so I was poking around at it thinking it was very clever of them to include one, so I had given it more than just a casual lookover...)

These are not new plugs, they've probably got about 3000 miles on them. They were new when the engine was rebuilt by the P.O.

And to answer yelcab: I timed it multiple times with a light. I checked it again when I fired it up today, still dead on. A week ago I pulled the top valve covers and verified that the crank pully marks were correct (they were).

I'm totally baffled. I can't figure out if this is something else happening with the motor that was badly coincidental to changing out the points, or if that could've caused this problem. I'm guessing whatever made a mess of the plugs is either a symptom of, or caused by this problem running.

H.G.P. · 05-08-2005, 03:37 PM

Maybe Wayne and the other experts can answer these questions:

1. What kind of plugs are you using?

2. Are they compatable with the new ignition box?

3. How does the car run with new plugs compared to the old 3K plugs?

4. Could the oily looking plug threads in the pics be from an installation where the threads were lubed from some anti-seize attempt?

350HP930 · 05-08-2005, 03:48 PM

While a pic of the electrode in the plug would tell us more, right now I am suspecting a plug fouling issue from either too much oil, fuel or both.

scottb · 05-08-2005, 06:08 PM

Quote:

Originally posted by dotorg
I had issues getting it installed in the distributor -- the pivot point for the points mechanism hit the plastic wheel, so I had to sand it down until it cleared.

Am I the only one here bothered by this....?

dotorg · 05-09-2005, 02:16 AM

Quote:

Originally posted by scottb
Am I the only one here bothered by this....?

Sanded the wheel down to reduce its radius a mm or so... not sanded the pivot point down. Although Pelican's website doesn't warn you when you buy it, aparently thats just what you have to do on the real early distributors. I talked to a number of people, and they all had to do that.

dotorg · 05-09-2005, 02:23 AM

Quote:

Originally posted by 350HP930
While a pic of the electrode in the plug would tell us more, right now I am suspecting a plug fouling issue from either too much oil, fuel or both.

It looks like the rest of the tip -- completely covered in carbon soot. Totally black.

I got an e-mail back from the engine builder who actually put this motor together for the guy I bought it from, and he thought it was just from running way too rich, and suggested checking the floats in the carbs, but considering all of the plugs I've pulled (1, 2, 4) were like that, it seems unlikely a single stuck float would do that. I'm making a semi-educated guess that two weeks of it starting and running poorly, and only when the pedal was to the metal did that to the plugs. (Or I'm hoping thats what it is).

I have another set of plugs to put in there, but I want to narrow the problem down so I have the least odds of fouling those before I put them in.

What I'm still baffled about is why it is the engine would run fine for five seconds before it starts to stumble...

dotorg · 05-09-2005, 02:26 AM

Quote:

Originally posted by H.G.P.
Maybe Wayne and the other experts can answer these questions:

1. What kind of plugs are you using?

2. Are they compatable with the new ignition box?

3. How does the car run with new plugs compared to the old 3K plugs?

4. Could the oily looking plug threads in the pics be from an installation where the threads were lubed from some anti-seize attempt?

For 1, 2, and 4 I couldn't tell you for sure. The new ignition box is just the optical trigger... the Jacobs ignition isn't new, this engine hasn't been used without it since the rebuild.

I haven't put the new plugs in because I didn't want to risk fouling them and needing yet another set, and I need to get something to measure the gap on the old plugs to set the new ones. (The tuning specs for this engine aren't the same as the stock engine because of the unusual combination of L heads and S cams)

Thomas Owen · 05-09-2005, 03:03 AM

Starting, 'most of the time', then stumbling and dieing sound to me like a fuel issue, not ignition. It could be, however, way to rich and is being flooded until it dies.... you would think it would help to 'goose' it at that point, but you say that hastens the demise....
Can you turn it over with a plug removed and check spark from a plug? Does that spark look healthy?
My guess is still fuel related -
good luck.

dotorg · 05-11-2005, 02:59 AM

So whatever it was, it wasn't fuel related. I put the points back in yesterday and the car fired up just fine.

Clearly the Crane is not a good option for SWB cars -- the parts don't fit the dizzy right, and even after you manage to get it all fitting, clearly there's some sort of an electronic difference with it. And worse, I could've bought ten years worth of points for what it cost.

Oh well, live and learn, at least my car is running strong again!

I'm amazed with the number of 911's out there that no one makes drop-in replacement electronic distributors like they do for so many older American cars...

B D · 05-11-2005, 10:25 AM

Dotorg I run the Crane XR-720 and a MSD box in my car without any problems at all. The only slight problem I had was I did not have the optical disk pushed down far enough on the shaft and the rotor sat to high in the dist. Maybe the XR-720 vs. the XR-700 was what you needed to make it fit.

Early_S_Man · 05-11-2005, 10:45 AM

dotorg,

Those plugs are hopelessly fouled, and a MAJOR part of your starting problem!

They appear to be NGK B9ES, which are too cold for your engine, except for very high speed/DE use in 100+ degree weather! Try a set of BP7ES or BP8ES -- they are certainly cheap enough to try both, eventually, but I would put the 7s in for now. New plugs will probably end your starting problem!