351 not firing

[cvbfireman]

not sure what the problem is.... at first i didnt have the ignition box in it because my 302 didnt have one and so with the new distributor i just cut the wires and fed them directly to the coil then realized no spark... so i figured out that maybe i should wire the ignition box i had sitting in a box up... so now i have spark... not sure if i have it wired right because the 2 wire connector the red wire is wired to the the - on the coil with the white going to the starting solenoid...


i am getting spark now... and the most i can get out of the engine is hiccups... any ideas on what i need to do next??? i really thought id have it running today....

 

[DirtDonk]

Yeah, something's not right with the wiring still. Sounds like some odd combination of parts. Can you say what exactly the distributor is? And what module (box) too?

List every wire if you can, and where they go.

Thanks. We'll get it fired up.

Paul

 

[cvbfireman]

Ok theres 3 wires on the dist purple/black red/black and black... Those plug right I'n to the box... It's the Standard ignition box... Then there's a green wire with those 3 and it says it's for the tach.... So I hooked that to the positive on the coil.... The second connector has 2 wires red and white... I hooked the red to the ignition power and the white to the starting solenoid pin..... The coil is a msd
Sorry I'm writing this on my phone the lady is making me go eat something since I've been wrenching like hell all day

 

[DirtDonk]

No problem on the typing. Good job under the circumstances.

Your Green wire is at least one MAIN problem. That's the trigger wire, and should go to the negative "-" side of the coil instead. The positive should have a Red w/green wire from the key.

Paul

 

[cvbfireman]

10-4 I'll give that a go as soon as I get back. Neighbors are goin to be stoked if it fires tonight and I have to break the cam I'n with the 1 chamber flows I have on it

 

[cvbfireman]

Oh yea and thanks for your help I really appreciate it.... Ha big dreams of it firing right up

 

[cvbfireman]

ok i have the green to the negative... still no go... im basically going off this diagram

except for the red wire that comes out of my fire wall i tied that in with the red wire on the ignition box and the + on the coil still getting the occasional hiccups (backfire)... not sure what to do..


fire order is 1-4 left side and 5-8 right side if i were looking at it from the front of the engine correct?

 

[marcm2030]

firing order is different for a 351w than for a 302. 351w firing order is 13726548. 302 firing order is 15426378. maybe this will help. Marc

 

[cvbfireman]

firing order is different for a 351w than for a 302. 351w firing order is 13726548. 302 firing order is 15426378. maybe this will help. Marc

yep i am aware we went off the firing order that the cam paper said

 

[cvbfireman]

Ok guys got it to fire but won't got much higher than 1500rpm before backfiring and sputtering.... Getting close but still no cigar

 

[Nightstick]

will it idle? did you time it?

 

[cvbfireman]

ok update..... got it running drove it... something still isnt right... if i hook the vacuum up to the distributor it dies.... unplugged its fine...


timing it seems to be a problem with the light so were just doing it off ear for now...

i need to find the wiring diagram for the alternator... for some reason mine only has 2 wires that go to it... my cousins and uncles have 3 i believe and we i drove it tonight the lights were surging at a high/er rpm... so i think i have that hooked up wrong... the 2 connections i have are a orange plug and a black and i believe yellow wire i have no clue where those are suppose to go

 

[DirtDonk]

Where are you hooking the line to the carb? If it dies when you hook it up, then it sounds like you're hooking it to the wrong port. The correct port will have little or no vacuum signal to it while idling, so should not effect your timing in the least.
Try another port.

Why is timing it with a light a problem? Don't be vague, give it to us straight. We can take it!
What is it doing? Are the timing marks not lining up? If so, maybe you've got the wrong pointer for your damper? Too many combinations, so it's very easy to get the wrong one.
Don't know if you need to call the cam manufacturer, since you have determined that the firing order is correct for a 351, you should be good to go there.
You just need to verify where you timing really is, so you can know what to do next. And you need to be able to follow the advance curve too, so you can determine what, if anything, is amiss with your timing.

2 wires for the alternator is fine. The large black one is for charging, and the Orange one is the Field wire that runs straight to the voltage regulator's "F" connector.
If still using the original Bronco harness, your ground wire (fairly important!) is molded into the strain-relief as the little attachment ring. It connects to one of the "GRD" posts on the back of the alternator and the other end (small Black w/red wire) goes to one of the mounting bolts of the voltage regulator.

Not sure what a Yellow wire is doing there. Only two common ones under the hood that I can remember. One is for a horn relay (if so equipped) and the other is for the voltage regulator's "A" connector.
That one should be connected directly to the large Black wire, but does not usually run anywhere near the alternator I don't think. Hmmm, I wonder if it's normally molded into the strain relief and would be exposed if the wiring harness were pulled apart.
I thought I remembered it being on the battery side of the harness, but maybe it's in the alternator side after all. Not sure, but it doesn't normally hook to the alternator itself.
Follow it up into the harness and see if it goes to the regulator. That'll tell you what you need to do with it.

Paul

 

[cvbfireman]

im not sure about the timing light if the pointer i have on there is the wrong one (i pulled it off the 302) or the balancer is the wrong one (off my parts 351) but where the engine likes to run the white line on the balancer is no where to be found..... i have the cam papers and it says the firing order so i know i got that right....

i just ran outside and took some crappy pics of the alternator... theres the orange cap and a black and yellow striped... with a resistor? on it where should these two wires go???

ha and sorry for starting new threads... i wasnt sure if this one would get enough looks

 

[cvbfireman]

ok im going to keep going on this post... so that resistor looking thing has 3 wires going into it and 2 out... so put that on the ground..... then the orange goes where and the black and yellow goes where?

 

[cvbfireman]

ok orange cap goes to the "F" resistor looking thingy goes to ground... and the black with yellow stripes goes?? to the "bat"?

im going to check the distributor in the morning... theres 2 ports on the passenger side of the carb the one i thought it was originally going into is the one that kills it... ill try it in the other one....

 

[DirtDonk]

The two connected already (Black and Orange) look correct. Just make sure that the markings on the alternator case match the wires. "F" or Field to Orange, "BAT" or "CHG" to Black w/yellow.

Not far from there (about 3" or so?) I see the black rubber molded strain-relief. Is that what you meant by resistor-looking thingy? If so, look for a small metal ring sticking out of one side. If it's there, find one of the "GRD" posts (small ones on the back of the alt housing) and attach it with the ring over a stud with a nut.
That should make you good to go on the alternator side of things.

If you're not getting any charging action, check the connectors at the regulator. With the key off, the Orange and Green w/red wires should be dead. Yellow should have full battery voltage at all times.
With the key on, Green w/red should have full battery voltage.

Paul

 

[DirtDonk]

Regarding the wiring of the ignition control module. What exactly is powering the Red wire again? It sounds like you may have it hooked to the coil positive to get it's power. Is that correct?
If so, try to find a better place. I don't know how it's effected by low voltage, but as you can see by the diagram, you want to attach it to full voltage, while only the coil gets reduced voltage. Maybe running both from the coil, especially with older and questionable wiring, is lowering the voltage so much that things are just working erratically.
Again, don't know that's a problem, but it's not quite right either.

Good luck.

Paul

 

[cvbfireman]

10-4 thanks paul should have put 2 and 2 together and realized that three going into 2 meant that the ring needed to be grounded....

we hooked a voltmeter up earlier and it was showing it was charging...but i definitely just left that thing hanging cuz i thought it was just a mount

 

[DirtDonk]

That's normal. It's just a secondary ground, in case your body grounds and engine grounds are not always playing nice. As happens in a 40 year old truck sometimes.
Nothing wrong with a little backup.

Paul