This is getting frustrating...new 445 reluctant to start.

[Lenz]

Great news, glad to see you're up and running and you gave it the pouring rain test drive as a bonus .  I for my part will sit back and pay attention to the input you receive on the dieseling issue, it'll be interesting to see how that is resolved.

[Yellow Truck]

Howie, I did originally pick up a mismatched coil and ignitor. I have an Ignitor, not the Ignitor II, and I bought a Flame Thrower II. Luckily for me (and for a change) I read the instructions before replacing the original ones and read the warning. I have a 1.5 ohm coil, the Flame Thrower II is only .6 of an ohm.

I think it is rich, the guy that got it to start didn't do anything to the carb, just started it, didn't even check the vacuum. I have the secondary blade open a fraction, just so you can see the bottom of the transfer slot. This gave some relief from having to open the primary too much with the idle screw, which was pulling fuel from the the transfer slot - when we first got it to run I turned the idle mixture screws all the way in on all four and it still ran at idle.

I'll check the vacuum at idle and then make a decision about the power valve and jetting, and go from there. May change the idle bleed screws as well, but one thing at a time.

I have a good ground from the back of the intake to the fire wall, and I have a big ground strap from the side of the block. I checked the continuity of the intake to the negative on the battery and got zero ohms, so I'm pretty confident with that. I have not specifically checked the heads to ground, but I'll do that as well.

[Bolted to Floor]

Glad to see it running.

[amdscooter]

Glad to hear you are getting it sorted! Been reading the thread with interest. I went through similar machinations with my ignition. Stock, mixed stock & Petronix, full Petronix.. mixed Petronix and MSD, full MSD. Drove me nuts. Plus I had the whole "pink resistor" wire I needed to bypass. 

Sounds like you are down to the short strokes now, get a vac gauge on it and adjust the carb. How much timing are you running initial and total?

[Yellow Truck]

amdscooter - it is at 13 - 14 initial now, I have not had a chance to check it with the engine running, we set it with the starter when we were trying to light it. When I get a break in the weather I'll check timing at idle and with some rpm on the motor, along with the vacuum. The distributor was re-curved to give about 21 degrees for a total of 34 or 35, with all the advance in by 2,950 rpm.

Once I have some miles and shifts on the clutch we will put it on a chassis dyno and set the timing to optimal.

[amdscooter]

^^^ Sounds like a good plan, let us know how it hashes out.

[runthatjunk]

That should have caused no spark at all, since that is where the switching is done to cause the spark.  I don't understand why grounding case of coil would make a lick of difference.

Your mechanic changed plugs, those could be a part of the dieseling condition also

[Yellow Truck]

That should have caused no spark at all, since that is where the switching is done to cause the spark.  I don't understand why grounding case of coil would make a lick of difference.

Your mechanic changed plugs, those could be a part of the dieseling condition also

Sorry - not following. What would have caused no spark at all?

I may pull a plug when it isn't raining (getting biblical) and see if the spark is better, and I have the old plugs so I can try one, but they said they saw a significant difference. No idea why you would have spark and no combustion, even weak spark, but it was running. Hope I don't need new plugs every time I want to drive it!

How would new plugs cause dieseling? I've not read anything about that. Also I note that it was dieseling on shut down the other two times we got it to start.

[NIsaacs]

It is not the new plugs so much as the heat range. Maybe the heat range is hotter, that can add to the run on. I would say your initial timing is too slow, slow timing requires more idle screw advance and adds to the run on. It also makes them hard to start, it sounds like you are not sure what the timing is?  What are you using for gas?

Nick

[Barry_R]

most often dieseling is caused by excessive idle airflow - blades are open too far.  I suggest more initial timing which will allow you to close the throttle up a touch to maintain idle RPM.  If that proves not a viable option you could look at adding an idle stop solenoid - very common throughout the 70s and 80s for exactly that purpose - closes the throttle blades when the key goes "off".

[runthatjunk]

I may have misunderstood, but one of your posts stated you grounded the negative side of the coil in search of a better spark and saw no significant change.   Grounding the negative side of the coil should cause no spark at all since the circuit becomes constant and never switches, since the positive side of coil should be wired to a constant voltage.



Missed that engine was experiencing run on prior to plug change.

[Yellow Truck]

Being decidedly NOT an expert on these matter: first I think grounding from the coil terminal is immaterial since the Pertronix unit switches the positive, we tried it because we were scratching our heads too much, and it made no difference to the spark quality.

Regarding plug temperature range, according to their site the NGK G-Power 7090 is a heat range 5 plug. Now NGK's website is pretty much useless but I think a 5 is about the middle of the range (2 being cool, 11 being hot). Not really sure how one goes about picking the initial plug, but I gather what I have to do is run it for a bit and pull them and look at the plug.

Barry, I'll look at the timing again. Assuming it is around 13 degrees, how much do you suggest advancing it?

[My427stang]

Being decidedly NOT an expert on these matter: first I think grounding from the coil terminal is immaterial since the Pertronix unit switches the positive, we tried it because we were scratching our heads too much, and it made no difference to the spark quality.

Regarding plug temperature range, according to their site the NGK G-Power 7090 is a heat range 5 plug. Now NGK's website is pretty much useless but I think a 5 is about the middle of the range (2 being cool, 11 being hot). Not really sure how one goes about picking the initial plug, but I gather what I have to do is run it for a bit and pull them and look at the plug.

Barry, I'll look at the timing again. Assuming it is around 13 degrees, how much do you suggest advancing it?

Something is goofy here.  The spark happens when the field collapses in the coil, and that happens because the trigger wire from the neg side of the coil is grounded through the distributor, be it Duraspark, points, or whatever.

The Pertronix should have a ground, a 12V wire, and a trigger wire.  The ground should be grounded, the 12V wire should have power during crank and run, and the trigger wire should connect to the negative side of the coil (with the wire from the tach)

Do you have something different?  I have NEVER seen a system where it fires off the positive wire.  Maybe you have the coil wired backwards?  I think they will fire that way but work poorly.  Just trying to make sense of your "switches the positive" comment

BTW, an easy, but not exact way to see if your primaries are too far open is to see if the ported vacuum on the pass side is alive at idle.  If it is, then you need to figure out why the primaries are so far open.  It could be the secondaries are closed too tight, or it could be you have other things wrong causing it to not idle well and need excessive primary idle.  Often, it'll run on because it's getting both idle and transition fuel, PLUS extra air and continues to chug.

[Yellow Truck]

Ross, I misread the wiring diagram, but I should have remembered that collapse of the field causes the discharge. I am looking at the forecast and we are promised sun, clouds, and a thunderstorm. Tomorrow only a little rain. May get a chance to do some work, and I will have a look at the vacuum. When we were first running it we were taking ported vacuum and it was showing 5 inches at idle, which explains why it was running rich and we couldn't get it leaner with the mixture screws - we were already into the transition slot and the idle position screw was so wide open we were into the ported vacuum.

Since then we opened the secondaries a fraction and it isn't running rich at idle.

[Yellow Truck]

Started her up today, she runs quite a bit rougher than the initial start so I took her out and ran her for about 40 minutes (went to an exhaust shop) and she runs nicely at the low end of the temperature range. She is dieseling on shutdown, but not severely.

Checked the vacuum - zero on the ported side, 5 inches on the manifold side. Here is where it gets interesting - on the Edebrock it ran like crap but made 7 to 10 inches of vacuum. I then put a timing light on it and it showed 11 degrees advance. I'm going to take it in on Wednesday and have O2 bungs welded into the exhaust behind the collectors so we do some work on the fuel mixture. I'll also wait till my buddy is free to look at the timing with me - I can't hold the light and rev the engine very reliably.

On the bad news side the headers I have a crap - the mating surfaces are not aligned correctly so some of them are at a 5 to 10 degree tilt, and the ports on the head are larger than the header inlets.

FPA got back to me and a set of their headers will set me back $1,000. OUCH! I asked my exhaust guy if he could fix them and he said by the time he did I'd have bought new headers.

Now the question is, who makes a decent set of headers that will fit the BBM exhaust port? I measured them and they are 2 inches tall by 1 7/16ths. I looked at a couple of makers websites and they are not specific. Hooker, for example, sell a set that they claim will fit a 428-390-352 4WD F100, but they are silent on the exhaust port they fit.