:help:Not too sure what happened.
This has been a year long project involving engine rebuild, interior restoration etc.
12 minutes into the break-in procedure, the engine just shut off, as if I turned off the ignition.
I pulled a spark plug and cranked the engine with a remote switch, I had intermittent spark, then nothing at all. :censored:
Same scenario when using ignition switch.
Replaced Cap, Coil, Rotor, and Wires....Plugs were new.
I have 5.43 Volts at the yellow wire on the coil. Can't seem to find what it should really be in my Chilton's.
I checked the two ground wires on the firewall, cleaned them up, seems like a good connection/continuity to battery ground.
What am I missing :banghead:
Rewind 12 hrs.
While cranking engine with remote switch at the solenoid, (had dist. wire off of the coil cause I didn't want it to start yet) I noticed the coil trying to arc to the block/coil bracket. That didn't seem normal so I started troubleshooting for a ground short. I hand-over-handed every :censored: wire in the engine bay. I didn't find anything strange except for the red wire (described as a 35 ohm resistance wire on the schematic) gets pretty warm to the touch. Resistor = warm, so I don't think it is a problem....I don't know for sure though.
This the only thing keeping me from goin for a long awaited Sunday drive :occasion14:
Voltage to the coil should be right around 6V, which you are basically at.
Maybe your ignition module decided to die.
The black wire going into the distributor base is an ignition system ground. I believe it just screws into the block or distributor base. Either way, if it has a bad connection, you'll have no spark.
Quote from: Draekon on June 18, 2011, 03:10:02 PM
Voltage to the coil should be right around 6V, which you are basically at.
Maybe your ignition module decided to die.
Is there a way to trouble-shoot the ignition module?
Quote from: ammachine390 on June 18, 2011, 03:11:39 PM
The black wire going into the distributor base is an ignition system ground. I believe it just screws into the block or distributor base. Either way, if it has a bad connection, you'll have no spark.
Does it ground through one of the screws that secures the pick-up module? Can't find anything going to the block from the dizzy.
It goes from the ignition module into the distributor. At the base of the distributor you should see 3 wires coming out, a purple, orange and black. The black grounds the ignition module.
Would it be reasonable to think I could hook up a temporary jumper from the dist. base to ground?
Or do I need to go off of that black wire exclusively?
This has to be something simple. Seems like it always is. ???
How long did you crank it with the coil wire disconnected? The coil will try to find a ground with the coil wire off. It isn't good for the coil when you do that. It can overheat and damage the coil. Your best bet is to pull the power supply to the coil if you need to crank the engine and don't want it to start. Also make sure there aren't any wires that may have got damaged during the engine install that may be grounding out.
Quote from: KyleB. on June 18, 2011, 04:30:01 PM
Would it be reasonable to think I could hook up a temporary jumper from the dist. base to ground?
Or do I need to go off of that black wire exclusively?
This has to be something simple. Seems like it always is. ???
I don't think so because whatever that wire screws into is most likely still a ground. Providing this is the problem, its just that the wire is not connecting to it. You could put a jumper from a good ground the the actual wire though.
I would just remove the dist. cap, and check the connection. It's easy and free. I think there known for corroding and causing no spark conditions. I believe some members have tapped another wire into the black wire and run it straight to the negative battery terminal.
Also, take a look at this.
http://forums.amceaglenest.com/index.php?topic=35631.0
Ground continuity from dist. housing to battery is SAT @ .001 ohms.
I disconnected and ran cont. test from ground pin in the connector (dist. side)=.001 good.
Did same for ICM and got 435 ohms. It must use the dist as a ground.
The part that has me puzzled is that it ran for a while then lost spark. Are there any fusable links in the spark circuit?
Thanks for all the help up to this point. I am going back and forth to the shop to try your suggested trouble-shoots. Good times :occasion14:
Ok, it seems like the ground connection is not the problem then. I believe the parts stores can test the ICMs.
Worse yet.
For whatever reason, it just started. :hello2:
Wonder when it will decide to not start again???
I better get the ICM tested.
Thanks for going through that head scratcher with me.
I don't feel real good about it running since I never found a "Smoking Gun"
I gotta get it to quite dying in gear with the brakes on now!!
Any tips for that one?? :blob1:
The ICM should supply 12 volts to the coil when the ignition switch is in the start position until the engine starts then switch and run through the resistor wire supplying 6 volts in the run position. The ICM needs to see around 3 ohms resistance in run, IIRC.
Try running extra ground cables from the block to the firewall and the inner fender(s) to resolve the "dying in gear with the brakes on now!!".
QuoteThe ICM needs to see around 3 ohms resistance in run, IIRC.
That's correct 1.35 Ohm from the resistor wire and 1.35 Ohm from the coil itself (together 2.7 Ohm).
Do you have ported vacuum to the distributor?
You should only have ported vac to the distributor when running the carter bbd if you have already done the ECM Test bypass. Otherwise you should have manifold vac to the dizzy.
Sounds like electrical to me. I agree if the engine was cranking w/ the coil arching out to the block you might need to replace the coil. The Duraspark II ICM is pretty bulletproof. I would look at coil/wiring before replacing the ICM. A simple way to eliminate all guessing and save trouble shooting time would be to drop a $100 HEI in place and regap the plugs. i spent several weekends troublshooting one of my CJ's and gave up. 15 minite install of an HEI and I was on the road.
not saying give up, but time=$$$ and with the HEI only costing $100 IT'S DEFINITELY WORTH IT.
If you want to check, an oil pressure switch will give you the same symptoms you seem to have. If you don't have it plugged in tightly or it is going bad, it will allow spark to flow when you first hit the key and at the end when you release the key, but you will have no spark in the middle. It's an easy thing to check, and if you need to replace it, is only like $7 at Autozone.
I replaced the coil a couple of days ago when I wasn't getting spark, should be good there.
The oil pressure switch was new during the rebuild, should be good there.
I am a little lost on the vacuum to the dist. discussion I have it going to manifold vacuum. All engine vac. lines are new. Looks like PO has done some hacking on the ICM wires, maybe bypassed?
I tubed it to the diagram on the EN for a "high altitude modified to low altitude". There's the part that has me wondering. Also, I have seen where other people have a high altitude jumper wire that is supposed to be grounded to the block when at altitude. Mine is double landed with another wire on a single ring lug. I think I may need to seperate those two wires.
BTW, there is a decal on the firewall stating "this car has been tuned for primary use at high altitude". What would be the things to change to make it for low altitude use? Vacuum and that jumper to the block?
I am back in the same spot as before.
I started it this morning to start working my way through the tuning fun....3 minutes of run time then it shut off. The other day it was 10-15 minutes of run time.
Thinking it may be something with the computer, I pulled the + battery cable hoping for a "reset" of some sort. But no luck.
Will these things shut themselves down if there is an operating parameter that the computer doesn't like?
As I had mentioned before, all ignition components are new....from starter to rotor.
And, it appears I have good ground from dizz to battery.
Anyone experienced and ICM go bad and act like this? :banghead:
from the fords I have owned in the past the ICM will just "go out". have you performed the ECM Test test yet?
Quote from: thereverendbill on June 19, 2011, 11:52:43 AM
from the fords I have owned in the past the ICM will just "go out". have you performed the ECM Test test yet?
Nope...ready to do it now though :rotfl:
Can you shoot me a link?
http://www.amceaglenest.com/~iowaeagl/guide/index.php?title=Diagnostic_ECM_Test
Normally, the ECM won't cause no spark conditions. However, the ICM can cause no spark and intermittent failure like your describing.
I am onboard with gronk and the GM HEI upgrade. I main reason I did one to my wagon is to nip the no spark situation in the but before i ever had a problem with it
Do we have a comprehensive "how to" and a parts list here on the Nest?
I am about ready to pull the trigger, this sux.
if ya want a good setup send me a PM and I'll send ya a link to the unit I got from "the bay" the wires are real easy to get or if your inclined to do so you can make your own because they are GM units
Another option would be the junkyard HEI like shaggimo wrote up. That way you don't have to buy/change the distributor.
Quote from: ammachine390 on June 19, 2011, 09:36:30 PM
Another option would be the junkyard HEI like shaggimo wrote up. That way you don't have to buy/change the distributor.
Or an MSD or other CDI box. I was also having intermittent spark problems. Installed an MSD Streetfire and threw the aftermarket replacement Duraspark box as far as I could throw it. It runs like a champ.
Check the ICM connectors to make sure they are clean. Sounds like it could be something getting warm or hot after a few minutes and opening a connection.
Can this be as simple as a faulty starter solenoid relay? These have the run osition that powers the coil. If the solenoid is faulty...... Under $20 part, bight be worth swapping just to be safe. If you need the 1 wire HEI, sned me your info. I also have 12V ceramic resistors for them (I alway run a resistor before the dist.) No more DII ICM