Author Topic: Bizarre engine problem: ( (Read 1327 times)

Dne' · « **on:** October, 20, 2011, 12:05:24 PM »

Hi y'all! Guess it's about time for something to mess up! I finally got my stang home, it's been at moms while I work on the apache.
I bought an MSD ignition to replace the HEI, but just the basic setup. I installed it and it ran great for several miles, parked it for a few hous waiting for the muffler shop to get my new exhaust tips

, but when I started it and backed out of the garage, it died suddenly!!

I called tech at MSD and they guided me through the process of checking the ignition system, after many phone calls and it still not even act like it would crank , I started checking EVERYTHING! LSS- I moved the distributor all the way towards the thermostat housing and it started

! But when I tried putting it back to the correct timing, it would die!

I called Herb(of course) and he was discombobulated as I still am! The photo shows where the timing is at this time. The onLy other thing I can expose is when I spray carb cleaner around the right side of the intake manifold, the engine starts chugging suggesting maybe a vacuum leak? Herb's going to come over sometime soon to give me his much needed advice of how to proceed!
I had the wires all neat; now it's not organized looking, so don't worry, it will look nice and neat when this is all over.
Advice is absolutely welcome; )
Dne'
One other thought, when I went to install the new distributor, I had the option for different mechanical advance springs, tech told to use some light blue springs for street, just thought I'd mention that in case it had some drastic effect on the timing.

Pss, the photo of the timing was taking with the engine running.

Dne' · « **Reply #1 on:** October, 20, 2011, 12:07:45 PM »

Oh, the yellow mark on the balancer is the correct timing in the photo above, but runs best at that spot right now.

silverblueBP · « **Reply #2 on:** October, 20, 2011, 12:33:42 PM »

There could be all kinds of things that happened. Timing chain slipped, damper slipped, dist gear slipped.

I had the roll pin that holds the reluctor in place break while at the track. Started running like crap and once I made it back to the trailer it died. Just barely got it in the trailer. A 5 cent part was all it was.

Dne' · « **Reply #3 on:** October, 20, 2011, 01:02:27 PM »

Thanks Mark,
I just came from the garage, started the stang, no bump back on the starter like associated with advanced timing(or retarded?). It sounds really ggood( see I'm starting to studder), but how would I know what true timing is? Or how would I proceed in making this right or in further diagnosing the problem?

silverblueBP · « **Reply #4 on:** October, 20, 2011, 01:46:04 PM »

So, it's running good now?

Start with the basics. Put #1 cyl at TDC of compression stroke. Check timing mark on damper, check where the rotor is pointing (should be #1). Remove the dist cap and make sure the rotor is fixed. Check to see if the reluctor is fixed.

Do you have the correct dist gear to match the cam gear?

Dne' · « **Reply #5 on:** October, 20, 2011, 01:51:42 PM »

It starts and revs strong, but I'm too chicken to drive it in fear of breaking down ! Maybe I can get my husband ( Gary) to follow me for a few miles, I could do that. So tomorrow I'll be more specific in being more precise on distributor location, etc , and report back what I find. So maybe I don't have a vacuum leak! That would be great!

Quote from: silverblueBP on October, 20, 2011, 01:46:04 PM

So, it's running good now?

Start with the basics. Put #1 cyl at TDC of compression stroke. Check timing mark on damper, check where the rotor is pointing (should be #1). Remove the dist cap and make sure the rotor is fixed. Check to see if the reluctor is fixed.

Dne' · « **Reply #6 on:** October, 21, 2011, 05:16:39 AM »

As it stand right now, I took the distributor out and checked the drive gear on it, and it looked ok, I tried turning it , or making the drive gear move, but it appears to be solid. I replaced the original mechanical advance springs thinking the ones I had in it were too weak( don't ask me of my thought processes of why

), crawled under the car to take a peak at the harmonic bal, eh, it looked ok, I re-installed the dist , but where it's supposed to go, fired it up and guessed at the best timing. I'm going to go drive around my neighborhood, the if I think it's ok, I'll drive itnto the muffler shop to get my new exhaust tips installed, I'll post an update, just really bothered by not being able to accurately diagnose the actual problem

, anyway, now I can shop for a neat air cleaner,since the HEI limited my choices

My engine right now with distributor where it's supposed to be!

Grabber70Mach · « **Reply #7 on:** October, 21, 2011, 06:10:59 AM »

Do you think you might have been off one tooth when you stabbed it in the first time?

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Dne' · « **Reply #8 on:** October, 21, 2011, 06:36:53 AM »

Hi! No, I had the dist right where it supposed to be, and at this moment the timing is way off target proven by my timing light, as in the photo above. The dist in that pic, the vacuum advance was right up against the thermostat, so I moved it back a tooth to where the dist is supposed to be. It seems to run ok, but something isn't quite right in the way that it runs, I may put those mechanical advance springs back in that I took out and see what happens.

Again, if I move the dist where it supposed to be(timing wise), it dies!!

Quote from: Grabber70Mach on October, 21, 2011, 06:10:59 AM

Do you think you might have been off one tooth when you stabbed it in the first time?

Sent from my DROID BIONIC using Tapatalk

AzPete · « **Reply #9 on:** October, 21, 2011, 07:36:32 AM »

Have you pull #1 plug and verified top dead center and the timing marks on the balancer and the #1 valves being closed???? This is to check on the timing chain.

Dne' · « **Reply #10 on:** October, 21, 2011, 09:19:21 AM »

Hi Pete! Actually, thats next on the agenda. I had the p valve cover off, forget why, but may remove it again , cause I won't be able to use the balancer this time as a reference? Right? So the reason I'll be doing thos is to rule out a timing chain issue or balancer issue. Right?

Quote from: AzPete on October, 21, 2011, 07:36:32 AM

Have you pull #1 plug and verified top dead center and the timing marks on the balancer and the #1 valves being closed???? This is to check on the timing chain.

180 Out · « **Reply #11 on:** October, 21, 2011, 09:24:04 AM »

I don't know what the problem is but I know what it isn't and that's the advance springs. Their function is to set the engine speed at which your timing is "all in." IIRC the lightest springs available will generally let that happen at about 3000 rpm. Heavier springs delay "all in" till higher speeds. So unless you're revving at 3K or higher in your garage, the timing springs are having no effect at all.

Another thing not to worry about is timing marks and timing lights. At idle, crank up the advance until the engine starts to slow. Then go drive it and listen for ping. Going up a hill in a higher gear is best for provoking ping. You back off the timing until you eliminate the ping, plus a small tweak more for safety. You can do this with or without the vacuum advance hose attached. But if you detach it, be sure to plug it. Vacuum advance is a fuel economy device. It adds a little extra advance at highway cruising speeds, which gives you more power at a given throttle opening. This saves gas.

You can always go back to the timing light if you want too, but just be aware that setting ignition timing is a pretty simple mechanical process that doesn't necessarily require a timing light.

All of us amateurs try to dream up all the causes of a problem. All but one of our guesses is usually wrong. So it's good to eliminate the possibilities that definitely can't be the cause.

Dne' · « **Reply #12 on:** October, 21, 2011, 11:05:46 AM »

Well thank you! Actually I just tried this, but right now it's acting like its got a miss, maybe one or more of my wires didn't work exactly correctly. The only way I have to check them is an ohm meter, wish I had access to a scope!!
To be honest 180 out, I just think there is something terribly wrong and getting out of my area of what I think I know. It was running kind of ok a while ago, now it's acting like it's going to die going down the street and eve while idling! I just think it's related to this timing mark phenomenon. So when it cools down enough I'm going to do what Pete said plus check all my s wires. So there's my plan for now. If it was Monday I'd put it in a shop, but I feel "I" have to fix it(with a little help of course).

Quote from: 180 Out on October, 21, 2011, 09:24:04 AM

I don't know what the problem is but I know what it isn't and that's the advance springs. Their function is to set the engine speed at which your timing is "all in." IIRC the lightest springs available will generally let that happen at about 3000 rpm. Heavier springs delay "all in" till higher speeds. So unless you're revving at 3K or higher in your garage, the timing springs are having no effect at all.

Another thing not to worry about is timing marks and timing lights. At idle, crank up the advance until the engine starts to slow. Then go drive it and listen for ping. Going up a hill in a higher gear is best for provoking ping. You back off the timing until you eliminate the ping, plus a small tweak more for safety. You can do this with or without the vacuum advance hose attached. But if you detach it, be sure to plug it. Vacuum advance is a fuel economy device. It adds a little extra advance at highway cruising speeds, which gives you more power at a given throttle opening. This saves gas.

You can always go back to the timing light if you want too, but just be aware that setting ignition timing is a pretty simple mechanical process that doesn't necessarily require a timing light.

All of us amateurs try to dream up all the causes of a problem. All but one of our guesses is usually wrong. So it's good to eliminate the possibilities that definitely can't be the cause.

Mach1Rider · « **Reply #13 on:** October, 21, 2011, 11:46:44 AM »

Not knowing much about your build, I think Mark has a valid point of the roll pin of the dist gear may have slipped.
When you had the dist out checking the gear, Did you look thru the roll pin?
The gear is a slight press fit and should not turn freely, But if the pin has sheared it will turn and throw off the timing.
Too many of the replacement dist have gone to alum pins that will shear under the back pressure of a high vol oil pump.
I found this out the hard way after mine had sheared and left me stranded.
IIRC, with the timing mark at TDC your keyway should be at 12;00 for a reference to see if the outer ring of the bal has slipped.

tarafied1 · « **Reply #14 on:** October, 21, 2011, 11:57:00 AM »

I would have to agree. If it was running okay when you backed it out and it died suddenly, then only by advancing the distributor would it start, something moved. Usually when they jump a tooth on the timing chain it's when you are starting it. The chain would have to be really stretched and the engine was just rebuilt so it's not likely that it jumped a tooth.
You say it's acting like it's missing though. If the cam timing is off it won't run well.
I really think you need to check the TDC, if that's okay then I'd pull the distributor again and check that roll pin.

Dne' · « **Reply #15 on:** October, 21, 2011, 12:45:34 PM »

I removed #1 plug, bumped the engine as close to TDC as possible, then had Gary use a piece of Coathanger to use as a tool to get piston precisely to TDC, I used a ratchet to to the crank back n forth to achieve TDC (a little doubt still of how accurate I got there).

One photo shows the timing mark, the preferred timing, and the red tipped represents TDC. It's in the wrong place? I'm confused!

I didn't look through the roll pin! I can take the dist back out.
Note!!!!
# just went out and pulled the dist, I can see through the roll pin

Mach1Rider · « **Reply #16 on:** October, 21, 2011, 01:07:38 PM »

Assuming that blue line is your #1 plug on the dist, then the dist is off.
My bet is the pin has sheared and is continuing to move more out of time.
The rocking back and forth to find TDC will cause the timing chain to center its slack.
Thus giving you a false reading on the bal.

Ps. just saw you can see thru pin, move the dist one tooth clockwise to get it back on #1

tarafied1 · « **Reply #17 on:** October, 21, 2011, 01:15:22 PM »

the timing mark should be on TDC (if it was before). If the balancer spun it wouldn't cause you to have to move the distributor. It would vibrate but still run okay. That would explain the mark being off but not the rest of of your symptoms. Something still doesn't add up. Are all the internal parts of the distributor under the cap secure? Stator didn't move did it?

Dne' · « **Reply #18 on:** October, 21, 2011, 01:47:25 PM »

Hi, I just checked the internal things inside the dist, all tight and new! You know, me being absolutely sure my method of achieving TDC the way I did, I'll repeat it in the morning. The crank is really tough to turn with a ratchet. Tomorrow I'll get it close with the remote switch, then turn the crank via ratchet so to rule out slop in the chain. But in getting absolute TDC? Kind of difficult!! Perhaps I can bring the balancer to "TDC" and see how deep my clothes hanger (depth checker) goes? The engine only has about 500 miles on it.

Overall, I'd like to rule out the possibility of the timing chain jumping a notch! I'd hate to pull that timing cover

. Its also a new balancer.

Quote from: tarafied1 on October, 21, 2011, 01:15:22 PM

the timing mark should be on TDC (if it was before). If the balancer spun it wouldn't cause you to have to move the distributor. It would vibrate but still run okay. That would explain the mark being off but not the rest of of your symptoms. Something still doesn't add up. Are all the internal parts of the distributor under the cap secure? Stator didn't move did it?

AzPete · « **Reply #19 on:** October, 21, 2011, 02:06:59 PM »

Yes, put you coat hanger in the plug hole, have one person watch it for movement, have the other person turn the engine to align the timing marks. You are so close that I think you are ok there. At the very top of the piston stroke, there is almost a dead spot of no up or down movement.....I say almost.....as it is very hard to see.

Looks to me like the dist. is off a tooth or the pin has sheared on the gear.

Does the rotor fit tight? Does the rotor have a bit of spring tension to it and snap back in place?

Dne' · « **Reply #20 on:** October, 21, 2011, 05:03:34 PM »

Yes Pete, Gary dhad a difficult time seeing,feeling the coat hanger move, so there's room for error in being exact without the purpose of the balancer!
As for the pin? It's ok!
I'm almost tempted to re-install the HEI with all of its wires and see how it runs, wouldn't take me long to do! And see if the timing problem is all a mis-diagnosis!! Maybe there's just something wrong with this new MSD dist!

Quote from: AzPete on October, 21, 2011, 02:06:59 PM

Yes, put you coat hanger in the plug hole, have one person watch it for movement, have the other person turn the engine to align the timing marks. You are so close that I think you are ok there. At the very top of the piston stroke, there is almost a dead spot of no up or down movement.....I say almost.....as it is very hard to see.

Looks to me like the dist. is off a tooth or the pin has sheared on the gear.

Does the rotor fit tight? Does the rotor have a bit of spring tension to it and snap back in place?

B67FSTB · « **Reply #21 on:** October, 21, 2011, 10:59:30 PM »

Dne
You mentioned early in this thread then , when spraying brake cleaner on the right side of the carburator , the engine responds some kind to it .????
If thats so , I think you have a vacuum leak between the intake manifold and heads.????
Are the spark plugs dry after several attemps to start the car ??

Dne' · « **Reply #22 on:** October, 22, 2011, 09:43:47 AM »

Guess what? It runs fine and is right on the timing mark!

Just for the heck of it, I checked all the plug wires on the MSD and all within the ohms range, ok two may be a bit higher, but that still doesn't account for the previous phenomenon! What do I do next? Put the MSD back on and see if it does the same thing?

AzPete · « **Reply #23 on:** October, 22, 2011, 10:11:56 AM »

There may be a defect in the other dist. Return it for an exchange.....

Dne' · « **Reply #24 on:** October, 22, 2011, 01:02:56 PM »

Yes Pete,
It's obviously a bad MSD dist. I had a mechanic friend just left, we put the MSD back in, for him to diagnose. He was betwixxed as much as I have been over the past couple days in trying to reason this. I'm kind of sad to see that the MSD is made in china, or that's what is stamped on the MSD coil package. We are so sold out to china

. However, I'll contact MSD Monday and see how to go about what to do.

Quote from: AzPete on October, 22, 2011, 10:11:56 AM