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A few Continued Starting Problems, and a New One as well. Also...


2002Scoob
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I just got done rebuilding my whole front end, and now it's looking like I might have the opportunity to do the back soon as well. Eff. 

 

Last night while out for a spirited drive, I noticed a New sound- a light clunking-grind when going around tight corners at speed which got exacerbated by the addition of throttle/power. If I had to pinpoint it's source from the drivers-seat, it sounds as though it's coming from the passenger rear. 

 

Tonight after the starting-tale I'm about to spin (pun there) I was just going to go to the grocery store, but the fear of not starting again lead me to another spirited drive before returning home where I again confirmed this new noise is not going away, and maybe getting a bit worse.

 

My primary suspect is a wheel bearing, followed shortly by diff/axels perhaps... I'll crawl under the car this weekend to confirm.  What do yall think? 

 

 

 

BUT... On to the bigger conundrum, followed by the bigger concern. Starting with Typically Italian Temperamental Carburatori's. 

 

@Stevenc22recently posted up a cold-start video of his rebuilt and similarly kitted motor that had me dumbfounded and green with envy. Brunhilde is a grumpy Frau in the mornings and needs her coffee. And don't even think of poking or prodding her (gas pedal) or she'll flood, and the only option then is to pull the plugs and air out the cylinders. 

 

On a cold start this is how it goes with Brunhilde-

 

Ignition on- (electric fuel pump is tied to ignition) wait 10-15 seconds for the lines to pressurize. You can usually hear the wine of the pump change tone when they do. 

 

DON'T TOUCH THE GAS PEDAL- Any pumping or tapping of the gas pedal at any time when not actually running typically nets a flooded motor- necessitating pulling the plugs to air the cylinders to air out. it's not worth it so I don't do it. 

 

Crank in 5-10 second intervals, waiting 5-10 seconds for the pump to keep priming inbetween. Repeat 4-6 times (sometimes more...) till she gluggs to life. At this point when she's glugging to life I'll lightly dab the throttle to get the RPM's up and keep from stalling, but that's typically not an issue. She'll idle a tad rough at around 7-850 rpm till some heat gets in the motor, and then idle will smooth and rise to around 1000 at operating temp. 

 

NOW, when it's a hot start it's usually less drama. Same as above, but usually takes 1-3, 5 second crank sessions to get it to fire up and she springs to life, depending on how long she's been sitting. If it's just filling up the tank, usually she'll fire on the first or 2nd attempt. If it's running into the store for 30 minutes or more, then it might take 3-4.  

 

I've got check-valves installed aft of the fuel pump in the trunk, and another installed before the carbs behind the fuel filter/pressure regulator (1.8psi)

 

Carb Setup-

COLD START DELETE INSTALLED

32mm Chokes (I've got 34's standing by)

125 mains 

180 correctors

55F9 Idle Jets

Not sure the pump jets....

F16 Emulsion tubes

40mm intake trumpets.

No clue the starter-jets

 

AFR@ Idle- 12.5-13

AFR@ Progression-12.5-13

AFR@ point when on the mains- 13.5-14.2/3

AFR@ point where air correctors come in will drop back down in to the 13's. As RPM's increase it drops down to the high 11's, but that's not till you're up to 5k or more, and I'm trying to stay away from such levels till she's more broken in. 

 

Hair-brained Theory #1- The fuel pump is triggered via a Relay hooked up to my ignition (Purple wire under the dash) that triggers a fused hot running direct from the battery. NOW, when you crank the motor, the ignition shuts off all accessory power on the purple wire while cranking, including the pump. I'm wondering if the lack of pump pressure would impact starting?

 

Hair-brained Theory #2 - (and maybe more likely) Whatever jet in the starting circuit isn't correct. I spent all evening yesterday pouring through Pat Braden's Weber book, as well as the internet, and haven't found anything regarding troubleshooting starting jet selection with DCOE's. If you go on to Eurocarb's website ( dellorto.co.uk ) they list a variety of options- but at 14-19 pounds EACH it's cost-prohibitive to order a variety of options like you would standard jets. 

 

65F5

70F5

80F5

09F5

125F5

 

Contributing hair-brained theory #3- Could my pump jets also be too rich? Not sure what they are either, to be honest. 

 

Any other insights as to what could be contributing to Brunhilde not being a morning-frau? 

 

 

And on to my other, other new problem- I'm afraid my starter might be giving up the ghost. 

 

Before tonight's driving adventure, I was doing more DCOE starting/reading, and found a fellow's article on living with/tuning DCOE 40's. His recommendation for starting practice was to prime for 10-15 seconds, pump the throttle twice, and that would be enough to start. 

 

NOPE. BS. 

 

Brunhilde does not like to be prodded awake. She wet her plugs and refused to start. After multiple, cranking attempts and waiting, I pulled the plugs, aired out the cylinders, and reinstalled the plugs and cranked. But this time the car made a wholly new noise that I can only describe as a zip-zip-zip-zip sorta noise, like a zipper. 

 

My first typically paranoid reaction was I'd done something absolutely terrible by pumping the throttle and had washed the cylinder walls of oil and that noise was the rings scrapping on my freshly honed cylinder walls. (I get this way. I'm sorry. It happens). So after freaking out a tad, I grabbed my oiler can, pulled the plugs, squeezed a few squeezes of oil into the cylinders, and cranked it a few times without plugs. 

 

Upon re-inserting dry plugs, the zip zip zip noise was still present, but she fired right up, which leads me to believe that my starter could be on it's way out. 

 

Has anyone else had a similar experience with a starter that's about to throw in the towel? I can't imagine what else it could be. Once running, the noise isn't there. And, once I got home after my drive I shut it off, and cranked it again and the zipper noise was still there. 

 

 

Sorry for the long post... I hope my writing is entertaining enough to make it worth reading and responding to!

 

 

 

 

 

 

 

 

Edited by 2002Scoob
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In addition- I've also got a 123 ignition dizzy- I'm not convinced a timing issue is causing the starting issues, but maybe they could be? 

 

Here's my curve that she seems to be happy with for now.

 

6@500

16@700

21@1000

26@1500

31@2000

36@2700

38@3000

38@3500-Redline at 6500


Steven suggested a more reserved curve of the following-

 

0@500

6@700

12@1000

18@1500

23@2000

32@3000

34@3500

35@6400

 

I tried plugging this in and it was no good. Brunhilde really likes the additional advance at lower RPM's. However, *I THINK he's also running 10 degrees of vacuum advance, and I've got no provisions for such, which could explain the difference? I'm still a little confused with exactly how to implement/program/account for vacuum advance, but I need to learn soon as I'm hoping to hook mine up soon to a custom adapter I'm going to try to make this weekend. More on that later. 

 

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Your new noise; have you checked to make sure your exhaust isn’t rubbing on the driveshaft or the diff flange?

 

I’ve experienced both and it makes quite a terrible racket. The engine moving around on the motor mounts can transfer down the exhaust to where it passes over the rear subframe. Worth a look before you stress over it too much. 

 

Can’t help with your carb issue. I’m sure you’ll get lots of good input from this group. I’ve been impressed with the volume of quality, knowledgeable help you’ve been receiving from this group throughout your engine rebuild. 

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Your new noise; have you checked to make sure your exhaust isn’t rubbing on the driveshaft or the diff flange?
 
I’ve experienced both and it makes quite a terrible racket. The engine moving around on the motor mounts can transfer down the exhaust to where it passes over the rear subframe. Worth a look before you stress over it too much. 
 
Can’t help with your carb issue. I’m sure you’ll get lots of good input from this group. I’ve been impressed with the volume of quality, knowledgeable help you’ve been receiving from this group throughout your engine rebuild. 


Oh man, if it's that simple I'd be super stoked. Good suggestion! It's entirely possible too. The noise wasn't there before the rebuild, and I did pull, paint, and replace my exhaust. I'll give it a look-see.

And agreed. The FAQ is the Jam.


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In my ignorance, but trying to help, it sounds like your choke isn't working for the cold start... And you mentioned a cold-start delete, which sounds like a choke...

 

And sometimes, when it's flooded, you can open the throttle wide (literally put the gas pedal all the way on the floor) and then crank it (holding the gas pedal down the whole time, no pumping)- puts way more air into the engine- and it will often start.  Do this with the dirt bikes all the time- they end up in funny positions sometimes...

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I'll be the first to admit I don't know squat about duals. That being said I would not expect your lack of an operating fuel pump during cranking to affect the flow of fuel unless the bowls are completely dry. I would imagine that all fuel flow out of the carb is either caused by vacuum or pressure generated by fuel delivery diaphragms within the carb itself. Could the hot engine be boiling off the fuel in the bowls?

 

I would be curious to look down the carb throats while cranking to see if there is anything "wetting" the throttle plates. I would also want to see what the plugs look like after a few unsuccessful cranks. Are they wet? 

 

The "zip" does sound like a flywheel/starter engagement issue. If it stops after the ignition switch returns to run then you are on the right path... unfortunately.

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1 hour ago, irdave said:

In my ignorance, but trying to help, it sounds like your choke isn't working for the cold start... And you mentioned a cold-start delete, which sounds like a choke...

 

And sometimes, when it's flooded, you can open the throttle wide (literally put the gas pedal all the way on the floor) and then crank it (holding the gas pedal down the whole time, no pumping)- puts way more air into the engine- and it will often start.  Do this with the dirt bikes all the time- they end up in funny positions sometimes...

 

No problemo, good sir. DCOE's came with a sometimes problematic cold-start mechanism that would enrich the fuel mixture for very cold starting. So far the car seems to start with the same sort of regularity whether it's 70 degrees outside or 40, and the car will never be driven in below-freezing conditions so I opted to get rid of it. 

 

As for the floor-it-and-crank method, for some reason this doesn't work with Brunhilde very well when cold. Or at least I get to the threshold of cranking where I feel nervous for the starter/washing the cylinder walls. I'd attribute it to the amount of fuel being pushed into the cylinders from the pump-jets just further exacerbating the issue. I have however used this method in the past for re-starting when hot and the car would sit for 5-10 minutes and refuse to start(which the check-valves seem to have solved. I got stranded at a few gas-stations due to this. Rather embarrassing. ), and under these conditions it would work, but cold, it just doesn't want to kick over. 

24 minutes ago, VWJake said:

I'll be the first to admit I don't know squat about duals. That being said I would not expect your lack of an operating fuel pump during cranking to affect the flow of fuel unless the bowls are completely dry. I would imagine that all fuel flow out of the carb is either caused by vacuum or pressure generated by fuel delivery diaphragms within the carb itself. Could the hot engine be boiling off the fuel in the bowls?

 

Well, typically if the engine is hot, (which probably keeps the spark-plugs dry even if too much fuel makes it in) starting is a non-issue. It's really when it's dead-cold and been sitting for a while, as in over-night or at least 3-4 hours. I do not have any sort of phenolic spacers to keep heat out of the carbs. If i had to wager a guess, I think it's taking a bit of time for the fuel to reach cylinders to ignite, and once they do, it's a fine line between flooding and firing. 

 

27 minutes ago, VWJake said:

I would be curious to look down the carb throats while cranking to see if there is anything "wetting" the throttle plates. I would also want to see what the plugs look like after a few unsuccessful cranks. Are they wet? 

 

Indeed so. If for some reasons she doesn't turn over, or fires, stumbles, stalls, and won't turn over after a few efforts; I assume the plugs are wet and I'll remove them to dry and also air-out the cylinders. and pretty much 100% of the time they're wet. 

30 minutes ago, VWJake said:

The "zip" does sound like a flywheel/starter engagement issue. If it stops after the ignition switch returns to run then you are on the right path... unfortunately

 

This is my fear.... Whomp whomp. engagement only, as in partially engaged? I've got a condition-unknown factory starter from my donor motor... but an E30 upgrade is a possibility if I can find one cheap.  Hopefully it's an issue with the starter, and not the flywheel ring-gear. I don't feel like pulling all that nonsense apart again!

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Here's my plugs from last night. They'd had time to air out so they're all dry, but were damp when pulled.

1.
6f374454333393b568b720bfcff2d34a.jpg
2.
08f88ede9eddd7e11cdea3be76d28ece.jpg
3.
260bf45d6a75f6427f30eb83e80f8971.jpg
4.
7ed8dbde4ef67f6b72926392a67bf645.jpg

Not perfect, but not bad and definitely not fouled enough to impede starting.

 

They were lightly used plugs when installed, but the cleanest ones I had. There's a bit of carbon deposit denoting the rich-condition I need to correct throughout the RPM curve. All the skilled plug-readers out there are welcome to analyze. :)


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Not sure what condition the engine was in before it was shut off prior to these pictures (idled for a period of time, just a short cold run, long/hot/hard run, etc.) but they are still quite "wet". Maybe try 1 heat range hotter plug. Change in color on strap should be roughly centered in the bend. 

 

 

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Try NGK BP5ES plugs...  Those look like the car is running super rich with blowby.  Compression good, leakdown good?
 
Mark92131


Car is indeed running rich, and I've yet to nail down the jetting.

The motor only has apx. 200km on it since being rebuilt, and I haven't pushed it hard for any duration so it's not even broken in persay, and it's quite possible that rings aren't fully bedded.

I ran a quick compression about 100k ago and it was all around 165-170.


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Small update. I went ahead and ordered some BP5ES's, and did a bit of investigating into each of my issues.

1. I feel I've cured what is likely my clunking issue in corners, and@bento likely was dead on. Where the exhaust runs over the rear axel it was rubbing on the driveline tunnel.
f9806946e2414480fa339cc9c0b17e28.jpg
I loosened up the clamps and readjusted everything to give the exhaust around 20mm clearance vs. what was only 5-6.


2. Did some investigation into my carbs a bit more. It's been a few years since I rebuilt them, and I forgot that with the cold start delete kit, you install blanking jets in the starting jet circuit.... so there goes that theory.

Pump jets are 35's

3. And finally, my biggest concern of late is this new starting noise. Before when starting everything was a pretty quiet affair...

Now, of you watch below you can hear this zip zip zip zip sorta noise that wasn't there before. I didn't have the nerve to crank it further. Because hesitant.

Take a look and listen and please let me know what you think/feel.
 

 

 

 

 


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Edited by 2002Scoob
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4 hours ago, 2002Scoob said:

Small update. I went ahead and ordered some BP5ES's, and did a bit of investigating into each of my issues.

1. I feel I've cured what is likely my clunking issue in corners, and@bento likely was dead on. Where the exhaust runs over the rear axel it was rubbing on the driveline tunnel.
f9806946e2414480fa339cc9c0b17e28.jpg
I loosened up the clamps and readjusted everything to give the exhaust around 20mm clearance vs. what was only 5-6.


2. Did some investigation into my carbs a bit more. It's been a few years since I rebuilt them, and I forgot that with the cold start delete kit, you install blanking jets in the starting jet circuit.... so there goes that theory.

Pump jets are 35's

3. And finally, my biggest concern of late is this new starting noise. Before when starting everything was a pretty quiet affair...

Now, of you watch below you can hear this zip zip zip zip sorta noise that wasn't there before. I didn't have the nerve to crank it further. Because hesitant.

Take a look and listen and please let me know what you think/feel.
 

 

 

 

 


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That sounds like a compression stroke. Are you sure all the spark plugs are tight? It really sounds like compression from the engine leaking.

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