390 Cranks over no start

["Whitey Ford"]

I have a 62 Uni with FE 390. I had the motor rebuilt about 4 years ago or so and its been reliable and great till this weekend. Nothing fancy but little cam, mostly stock, and i didnt cheap out on parts.

Anyway all was well and drove the truck last weekend. I did notice it started to get a little harder to start but it did start. Note every other time it starts with a twist of the key. Great idle, great start, great running. Anyway went to start it and NOTHING....just cranks and cranks and cranks. One time it actually backfired through the carb and caught it on fire a little bit.

I got spark, just taking the spark plug out and putting on the valve cover, and i have fuel. The spark only seems to spark at first part of start then nothing, thats from the the coil to dizzy wire. Shoudlnt the sprak continue as it hits each spark plug wire contact? I even tried another coil out the box and a new ignition switch...same results.

From all the reading maybe the timign chain slipped, so i pulled the fuel pump out and felt the chain. It seems a little loose but not too crazy. I guess any slop is bad slop.

Either way, any suggestions? I did the TDC and put the rotor to spark plug 1 yesterday but same results. Just cranks and cranks.

FYI this is a ready to run MSD distributor. No points.

[bruceandersson]

How are you judging that you have fuel? Do you get a good squirt when you pull the throttle?

I am not familiar with the MSD units, are these electronic or do they have points? I've had points, and distributor caps just fail.

I'd start be replacing plugs, points, condenser, rotor and distributor cap - your typical tune up. Set the dwell and the timing.

Then use a little starting fluid to see if you get anything.

[slick4x4]

Are you saying it doesn't keep sparking while your cranking ?
Will that is definitely not right.....

If your timing chain did jump
Sometimes you can get an engine to run by advancing the timing on distributor

["Whitey Ford"]

Its the magnetic trigger type distributor so no points, condensor or any of that.

Ive replaced the coil, ignition switch and going to do the plugs. I get a good squirt of fuel at the carb and even tried starting fluid...nothing. Its a good strong cranking though.

Yes slick 4x4, at the coil wire to dizzy when i hit start it will spark one time at inital crank and then wont keep a spark after. Thats why i chanegd the ignition switch thinking it wasnt getting power to the dizzy but samr thing after i changed it.

[LM14]

Call Autotronics and they can walk you thru the testing process for an MSD.

An MSD box usually either works or it doesn't, they very rarely fail intermittently, not sure about the ready to run distributors. You need to check spark at the plug not the coil wire. Check to see if you have spark at the spark plug grounded.

There is a module in an MSD ready to run distributor.

I would call Autotronics, it gets too expensive just changing out parts.

SPark

[LM14]

Call Autotronics and they can walk you thru the testing process for an MSD.

An MSD box usually either works or it doesn't, they very rarely fail intermittently, not sure about the ready to run distributors. You need to check spark at the plug not the coil wire. Check to see if you have spark at the spark plug grounded.

There is a module in an MSD ready to run distributor.

I would call Autotronics, it gets too expensive just changing out parts.

I have seen some really worn timing chains, I have never actually seen a chain jump gear teeth. I've seen them stretched enough to mess up the timing but not actually move on a gear.

SPark

["Whitey Ford"]

Yeah the ready to run is a basic plug and play...see below for how to test it. So it seems its good. Ill recheck this. I did check the spark at the plugs which did spark but seemed more orange and not very high output type. I got new plugs that im going to install and try. I sure dont want to get adizzy if thats not it.

Seems it should spark at every plug location when testing at the coil....

Another popular distributor is the Ready-to-Run line. These distributors are easily identified by the three pin connector that has a Red, Orange and Black wire. In some models, there will be a separate Green wire that is used for a tachometer signal wire. These distributors do not require and external ignition control as they have a built-in high output ignition module.

To check the Ready-to-Run Distributor, confirm that there are 12 volts on the Red wire when the key is On and while cranking. It is important to confirm 12-volts during cranking as many older vehicles may have resistor wiring or ballast resistors inline which could affect the voltage needed to fire the ignition.

[Toyz]

I have seen the timing chains "slip", but a metal gear just jumping a single tooth is something I've never seen. Usually if they "slip " it is a considerable amount. For that reason, I would not recommend attempting to check through the fuel pump hole. Simply "rock" the harmonic balancer until resistance is felt, then "rock" it the other way. Your problem sounds like a defective module to me, but a compression and timing check may reveal other problems. I am not an advocate of wanton parts replacement, but the MSD modules are fairly cheap; thus a good diagnostic tool, as well as a spare which might come in handy the next time. If you have verified "near Battery voltage while cranking", and have checked compression and timing, I would recommend purchasing a module. The reason I do not say "12 volts" while cranking" is that you may not see a full twelve volts given a healthy engins and resultant starter current draw. If you see near 12 volts, that should be sufficient.
Paul

["Whitey Ford"]

OK well here is an update. SO yesterday i checked voltage at the coil with ignition on and im getitng 12 Volts. Couldnt check at cranking cause i didnt have anyone helping. So i figured just messing around i would tunr the dirstibutor and try and again. So low and behold it catches a little but only for second when i let go of the key from start to run. SO i turn the dizzy some more and the carb catches fire a bit. I turn it the other way and bam the engine is running BUT Only if i keep my foot on the gas. SO i let it rest try it again and it starts, idles eveytrhing great. No idea. Turned it off and retried and it started right up...idled and eveyrhting.

However, i tried again this morning and nothing. Im now wondering maybe its the fuel pump...

[slick4x4]

Sounds exactly like my 77 (stock) ford when the ignition box started going bad
Sometimes it would start perfect
Next time , crank & crank......
Definitely sounds like ignition problems to me
I'm not thinking it's a fuel issue
My

["Whitey Ford"]

I think so too...just hoping not. I think its the distributor at this point. I guess i need to just get a points tpy edistributor form napa throw it in and see what happens. I checked the one i have and the gears and pin and everything seem ok, but could be sheared inside...soemthing.

[Toyz]

MSD is usually quite good as to customer service. I would certainly contact them. I have found them to be extremely helpful and knowledgeable. Their products are not failure free, but I would definitely prefer buying a replacement module as opposed to a questionable rebuilt point type system and rewiring to accommodate the needed resistor. NASCAR still seems to believe in MSD, but are realistic enough to run redundant systems!
Paul

[oldtrucks]

Whitey.

Sorry to hear of your problems. My take on your problems are the ready to run dizzy. Like anything electronic it is always prone to fail when least expected. I hope MSD will help you resolve this issue. I have used MSD products for many years and have had only one failure with a 6AL box but it was at least 10 years old when it failed. That being said a couple of my friends are having the same issue with their ready to run dizzys not all of them are MSD tho. Seem to be a trend to me.

Over the years I have worked out an ignition system that has proven very reliable at least for me. I use a stock magnetic pickup Ford dura spark dizzy, a 12 volt coil from a late model computer controlled engine and a MSD control box. Currently using a MSD Street Fire box but any control box would work. Again I hope things get resolved soon.

["Whitey Ford"]

Yeah thats where my thought was this whole time. just hate to spend the money just to see. Im going to call their hotline too and see if there is a way to test it differently...

[Toyz]

Here is the BEST solution, IMO http://www.davessmallbodyheis.com/
Might also check with Bobenhotep to see if he can make you a conversion module.
Paul

["Whitey Ford"]

Im just still confused on how it finally started, idled, and reved like it use to then just cranking again. god i hope i didnt kill the coil because of some issue.,

[Toyz]

Do some research; I think you will find multiple complaints regarding the same symptoms, especially on the Ford applications. If you have an epoxy coil, it may well have failed because of module problems. The culprit in both cases is heat, neither the distributor nor the coil can take the heat generated by repeated tries at starting. The problem thus multiplies, making competent diagnosis a moving target. IF you stay with the distributor, and I would; it's a big investment, whether using another MSD module or a conversion, be sure to vent the cap if not done already! Ford also moved the coils away from the engine at one time, then finally wised up and did the same thing with the TFI modules!
Paul

[charliemccraney]

You need to check the voltage while cranking. It will tell you the condition of the battery. A battery that is on the way out can crank the engine over but the voltage drops considerably and for some electronic ignitions, it is enough that they won't work.

[LM14]

If it started and ran fine when you turned the distributor, I would suspect a loose wire, dirty ground or something in the distributor
loose.

SPark

["Whitey Ford"]

yeah i tried again last night and nothing...just cranking. I moved the distributor and nothing now again. Im going to check to make sure i have TDC again so i know its not a chain slip but i just cant help to think its the dizzy. I looked for a module replacement on the ready to run MSD and there is nothing.