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Join Date: Mar 1999
Location: Vancouver,Wa.
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Engine Gurus
Tain't often that I get stumped, but there's the situation.
New SBF. It runs swell, makes a boat load of power for a 331. All the vital signs look fine as frog hair........until I checked the timing with 2 different timing lights. My pro buddy checked it with his light also. The reading? 40ish... deg advance at idle (bout 1200 rpms).....it's beyond the marks on the balancer and shouldn't even run.....but it doesn't react as if the advance is way off. All the usual suspects have been checked. The 0 mark & pointer are right on with TDC on #1....triple checked. As my buddy says"this is impossible". Obviously, those timing lights are wrong.......but how/why? There are some wild cards in the works. MSD digital 6AL, pertronixs dizzy, MSD tach adapter and a bunch of electrical stuff that didn't come with the car (65 Mustang) that *shouldn't* effect the ignition. My next step is to replace the distributor with a similar unit....... poke & hope. I don't mind earball tuning a bit......but I like to know where I am from the get go t. Sure, I shoulda stuck with something simple....like Porsches. ![]() The pic don't help none, but I needed an excuse to get it in here. ![]() ![]()
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JPIII Early Boxster |
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Pulley locking key sheared?
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A logical assumption, but nope, checked & the the balancer is visually OK.
The physical relation ships of the motor are OK as far are we can check without a total tear down....but am unable to check actual cam timing.......there would be rude noises, smoke, & flames were that the case. The engine pulls strong to 6k. I think I'll disconnect the tach adaptor first.....
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JPIII Early Boxster Last edited by J P Stein; 09-25-2014 at 07:14 AM.. |
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I seen MSD wired incorrectly for the current application and still run OK to a point...I'd double check and then triple check that.
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This is what I was thinking also. It sounds like you have already checked it, but if not, use use a whistle, or screwdriver, or whatever, down the plug hole to make 100% sure that the marks on the balancer co-incide with actual TDC. I am assuming there is an aftermarket crank to get you to the 331?
I have heard that some timing lights will read wonky with MSD, but I have several different lights, and they all function perfectly with every MSD install I have ever played with. I'll keep brainstorming...
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D idn't E arn I t
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Bypass the MSD, set timing, reconnect MSD. It wouldn't run at 40BTDC, period. It's your equipment. If you are lined up at #1, have the gun actually tapped to that wire, the balancer is verified not to slip, and it's truly at TDC that's all you need to know. Unless you have the distributor clocked wrong or reading the wrong wire that's not possible.
rjp
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Just a thought, but the tab on the timing cover in the correct location? I ran across this once on a chevy BB.
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The Unsettler
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Ditto.
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Quote:
The crank is a forged after market bit...probably from China. I didn't buiild the motor...a crate jobbie. I hear you on the TDC bit......but, I've been working on this for more than a week. and am pretty much convinced that the lights are giving false readings....an electrical dysfunction somewhere. The engine wouldn't run at 40 deg initial advance.......it just barely runs at an indicated 35 deg advance....runs best at 45-47 deg (earball WAG).. My pro buddy has been calling all his sources and they all say"It won't run at 40 deg"...They'll get no arguement from me. The only reason I'm pursuing this is because there is an outside chance that the plugs are not firing within an acceptable range before TDC. I ain't at my wits end on this, but close enough to see it. ![]() I'm hoping my personal light will come ON......with some help.
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SBF?
if you had the timing light on the wrong plug wire that would be around 90 degrees. when i put an MSD in my 930 the timing was waaaay advanced. it barely ran and you could really tell it was not right.
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Probably no relation, but way back a friend and I bought a Ford muscle parts cam for his Mach 1 and installed it. Wouldnt run for beans, spitting and popping. After a couple days and phone calls, found out that the cam we installed was set up for a different firing order than the stock one. Switched the wires around and all was well. that being said, number 1 is still number 1, so probably not related to your issue.
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Pull the plug and check to make sure piston is truly at TDC...
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My old Sears timing light (MIA) worked fine on my 6 cly 914 with an MSD. The Mustang is nearly 50 years old and for most of its "repairs" were done by hammer mechanics. The car will out last me and I refuse to pass this crap along to the next fella.
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i have an old snap on timing light, non adjustable. for some reason i just dont trust the ones that have the dial to dial in the advance.
i dont know how far mine was advanced but it was at the limit if running. the idle have a VERY distinct high pitched idle to it. (not RPM wise.) i have always said i prefer to have my vacuum retard connected because the idle sounds much better. it has a deeper throaty sound to it, which goes to say why the idle sounded high pitched and thin with timing advanced. "thin" is a good way to describe it. i think it may have been popping too, not sure. does the timing advance as you increase the RPM's have you tried retarding it to see how it runs if you drive it and put it in say 3rd or 4th at a slow speed and floor it, does it spark knock
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I have always found that harmonic balancers wander off. Not to be trusted .
They slip on the rubber ring.
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Hummmm, that is a strange one. Some things to check and I know they might sound silly but: are you checking the correct number 1 cylinder, front passenger side. Chevy's are the other side and back in my stock car days many, many years ago guys would get mixed up! Is the timing light(s) made to work with a MSD box? The one I had would not work with my 914-6 after I hopped up the ignition so I had to buy another light. It read fine after that. Another item, what is doing the dwell, points or breakerless in the distributor? I did not see you mention what is inside? Last of all does the distributor rotate counter clockwise as all Fords do? The cam and distributor might be the wrong ones?
I would end the anguish and go to a dyno shop and pay them that $$$$ for an hour or two as they will hook up everything and give you all the readings for all settings such as advance, dwell, exhaust temps and mixtures. Good luck |
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Some good advice so far, my only input would be to start @ ground zero and check everything. Are you on the correct (#1) cylinder/are the timing mark and balancer agreeing on TDC/and so on, and so on.
The old Vince Lombardi, "This is a football" speech. ![]() Always the best approach when something is really weird. |
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Quote:
Verify TDC with balancer.
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The first thing I'd do is make sure the plug wires are installed correctly. Like others said, make sure the timing tab is in the right place and that the balancer isnt moving.
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