Trying to get 351W running. Dad and I spent two days trying to get it to run right re: timing and never could. No deviation from tdc would get it to run reliably. When set to where it "should" be and it Spurs and sputters. Checked distributor a bakers dozen times. Thinking maybe timing chain may have skipped a tooth but we found these two electronic boxes, one on each side fender that we don't know what they do.

Dad suggested before we remove all the stuff to replace timing components that I should ask the fine folks here if those two boxes have anything to do with ignition timing.

Anyone know? Sorry if formatting wonky, on phone in a field at the moment. Appreciate any help

 

I am unsure about the module in the second picture, but in the first image, that is your "duraspark II" ignition module.


I believe you can remove the module and have it tested at a local auto parts store.


If it is found to be bad, you can get a new motorcraft one for around $40 online.




Thanks,
Cody

 

Yes, that silver box on the driver's side wheel covering is the electronic ignition module; those things fail after some time (that one in that picture is already an aftermarket variant) and can be tested at a decent parts store like Cody just stated.

The box on the passenger side is the alternator regulator and has nothing to do with the electronic ignition, leave that one alone.

 

Thanks fellas, I'll pick it one up at the local parts store and see what happens.

 

Take the original module to the auto parts store and match it up, as there's more than one. And be aware that most auto parts store modules are made in China CRAP!

The 3 step scenario of a failing DuraSpark ignition module:

1) Module overheats, engine dies. Module cools down, engine restarts almost at once.

2) Module overheats, engine dies. Module cools down, engine restarts in an hour...or so.

3) Sooner or later, usually sooner, the module overheats, BURNS OUT. Now the engine will not restart.

Taking the module to an auto parts store to be tested. Will test OK unless the puppy has burned out.

Engine heat is the mortal enemy of these modules, especially radiating from the V8's red hot left exhaust manifold.

When replacing, use some washer to space it further away from the fender apron. The more airflow, the better.

1980/83: Inside the dizzy is the stator aka magnetic pickup coil. These also fail, so I suggest if replacing the module, replace the stator too.

 

Just the fine folks, huh? What about me? Why am I excluded?

A few questions for you:

1) Have you confirmed the presence of a good strong spark? I'm not especially concerned about the actual timing for the moment. The timing gets checked after making sure the spark itself is good.

2) What's the recent history of the truck? When did it last run okay? Has it been your daily driver, always reliable and lovingly maintained, but recently you did some other work and now it won't start? Or was it found abandoned in the refuse pile of a salt mine, and the squatter living in the cab has no idea when it last ran? Something in between?

3) How far is up?

4) Why do socks fall down yet underwear rides up?

 

Is it 180 deg off? Make sure #1 is on compression stroke valves closed.

 

LOL you need help!!!

 

Double post

 

Replaced module, seems same issue but ran into more issues that need to be dealt with. I moved and had to store it in parents back field and nature ran it's course. Found it wasn't getting gas. Narrowed it down to no gas from tank, pump works, so will clean tank, filters, and probably run new fuel lines. Also the hook for the valve in carb bowl was just... Gone. No trace of it. Looks like it rusted away to nothing which doesn't bode well. Getting carb kit tomorrow to rebuild/clean then hopefully can continue diagnosis. It was running fine then I found the valves were completely covered in gunk, PO never changed his oil. Cleaned it out, seemed to run ok with some stuttering. Wanted to fix stuttering and it's progressively gotten worse from there. Impossible to properly time, something seems off. Its been a year but I remember it ran best wayyyyyy off, like 30 deg or something silly like that. Once we get fuel issues resolved, will start from zero again. If no success, I guess we'll check the chain. Already got the parts but a lot of work. That's what Christmas vacations are for!

Getting good spark, did check for 180 out. Just want to get it running to sell; I need 4wd and I can buy one that has it for less than it would cost to convert. Got freaking $1000 worth of Michelin tires on it too XD

 

Well said sir. Well said.

Merry Christmas.

 

Thanks for all the history details. Seems we are closer to the salt mine squatter scenario. Based on what you've detailed, you may not have an ignition problem at all, other than maybe a timing issue. I'll second your idea to start troubleshooting from scratch. A few random thoughts, in no particular order:

The timing marks may not be accurate. The outer sleeve of the crankshaft pulley/vibration damper can slip, throwing the marks way off. Remove the #1 spark plug, insert a soda straw in the hole, and use a socket and breaker bar to put that piston at TDC. Watch the straw to determine the piston position. Do NOT use anything rigid instead of the straw. I do not care to discuss how I know this. With the piston at TDC, see if the timing marks show the same.

While you've got the socket and breaker bar handy, check for a stretched timing chain. Remove the distributor cap and watch the rotor. Turn the crankshaft in the normal direction to take up any slack. Then turn the other direction and see how far the crankshaft rotates before the rotor moves. If the timing chain had jumped, it will be loose enough to show up when you try this test.

Definitely fix your carb. The missing clip? Is that the one that lifts the needle valve as the float arm moves? If missing, that could cause a very lean condition.

You can run a poor man's fuel system test with the use of some starting fluid. Disconnect and cap the fuel line feeding the carb. Stuff a rag down the carb throat and manually cycle the throttle a few times until no more fuel comes from the accelerator pump nozzles. This means the carb bowl is now empty, which will make sure the spark plugs don't get flooded. Remove the rag. Spray about a 3 second burst of starting fluid down the carb throat and try to start the engine. The starting fluid is all the fuel you'll need for the engine to run for 5 or 10 seconds. If the engines fires up for a few seconds, you will immediately know the spark is good, the timing is close, you've got some semblance of compression, and the main problem is with the fuel system. One caveat: If the engine does not start up immediately on starting fluid, do NOT keep spraying more. It's like Bryl-Cream, a little dab will do ya. No lightoff with starting fluid means you've probably got an ignition problem keeping the engine from running. More starting fluid in that scenario is only good for singing off your eyebrows, so don't go there. Put away the starting fluid and investigate the lack of ignition.

 

Thanks for the tips fellas. Truck was in horrible condition when I got it;the past year hasn't helped. Dropped both gas tanks and moving them sounded like the were filled with rocks and sand. Could push holes in the side, they were so rusty. Never seen anything like it. Needs new tanks, sending units, and lines. Ran line from a gas can and confirmed we were getting fuel in carb when throttling. Figured it wasn't worth getting new tanks if it can't run.

Confirmed it's getting fuel but rebuilt carb to make sure everything was clean. Used comp gauge to find comp stroke tdc, confirmed it matched zero on crank gauge and mark. Set distributor and re-ran all spark wires just to make sure. Would only fire once or so per rev.

Pulled all plugs, cleaned them, and checked gap. Now not even one firing per rev, dead. Running better before we cleaned the plugs. Yah, rechecked cables. Pulled valve cover and verified that valves were correctly timed at comp tdc.

It seems to be getting spark, fuel, and air and timing seems good. Did comp test when I got it but will do it again. Spark test light shows spark on #1, will check all 8 tomorrow. Will also run a scope down carb to check intake internals. Will also do that poor man's fuel system test but starting fluid didn't seem to help us tonight.

We've never been unable to get an engine to run, running out of ideas hah.

 

Any chance you've got a 302 instead of a 351W? Similar external appearance, but different firing order. Even if your VIN sticker indicates a 351W, that's no guarantee somebody didn't swap in a 302 at some time in the last 30+ years.

 

The order on the intake matches that for 351W. My understanding is that 302 intake is smaller, and the intake fits, so thinking it's a 351W.