View Full Version : At a lost
07-19-2007, 02:45 PM
Dont know if anyone has come across this before but my bronco 78 400 shuts off ( no spark ) when it gets hot. I have changed the coil to a msd and have 2 extra ignition modulers and if i change it when it shuts down it still wont start :mad: till it cools down. The distributer is 2 years old and seems fine but it could be the magnetic pic up but cant figure out how to change it without replacing the distributer. Before I blow this peace of sht up does anyone have any ideas. :dontknow:
07-19-2007, 02:49 PM
nope sorry cant help ya:cool:
07-19-2007, 03:41 PM
Maybe contact MSD or one of their dealers..Lordco sells that stuff, someone there may know. :dontknow: Good luck. [cheers]
Or maybe it's your fuel system..getting gas?
07-19-2007, 06:02 PM
I HAD A SIMILAR PROBLEM, 78 F250 351M . MINE WAS A FUEL PROBLEM BUT YOURS SEEMS TO BE ELECTRICAL, GOOD LUCK[cheers]
IIRC the pickup is $20 niehoff item
my rebuilt Lordco distributor (my cost is $77) had the pickup die 4 months after warrantee
10 minutes to change
intermitants like that are really hard to troubleshoot
I found an entire website on Duraspark troubleshooting when I needed to find what died on mine.
you need a DVOM and an analogue meter to do all the tests
I dont have an analogue
like you I had a spare mod so I rules the MOD out of the equation right away and just hunted the dist and wiring util it became obvious my new dist pickup was dead.
07-19-2007, 06:43 PM
my only guess is that possible the ignition modules could be hagerd i had a similar problem with my 390 it died when the engine compartment got muddy and hot i guess it clogged the heat sink on the modual. Dont have a fix for ya but i might consider tearing out the modulal and using an older distrib and just a simple coil. This solved my problems[cheers]
07-20-2007, 10:28 AM
Maybe this will help.. ran into a similar prob with my EB... running a 351w
Check the litle ground wire INSIDE the distributer.... the surface under mine was dirty.. I got a stronger spark after that.
also.. check your fuse box where the power wire for the ignition comes from... had a bad solder in there and it would fail and shut off the truck :confused0006: always seemed to happen when it got hot!!
hope this helps.... keep us updated. Some wicked gearheads around here
07-20-2007, 11:31 AM
do you have a circuit breaker in the ign fuse holder? might have a dead short some where, and it just gets hot, and takes a while to cool down and make concact again.
07-20-2007, 01:17 PM
Thanks guys i will try them all, m j how do u get the mag pic up out without taking the distributer out or is that the only way and do u know the name of the website. Thanks Larry i will look to see if its that.
it looks like the magneto pickup is riveted on but its the whole assembly thats riveted together as i had looked at the new niehoff part but ended up not needing it.
correct me if im wrong but theres a little keyway cut in the shaft that the ?chopper wheel? slides on and needs to be removed in order to get the mag assembly off:dontknow:
edit* PM or email me if you need more instruction. I have the printout from the TS guide I used in the shop, i will get the IP addy from it shortly...
you do not have to pull the distributor
right this second I do not recall having to pull it apart to do the pickup
I think it just clips on
if you do need to disasemble the top part of the dizzy I can give pointers and a link to that....
IF you need to pop the magetic rotor thing off keep a close eye on the rollpin that locates it to the shaft so you do not drop it down into the guts.
same deal with all the little clips...
c clip on the vacuum advance...
to get the magnetic rotor off, you 'gently' pry it with screwdrivers from both sides at the same time
pull the c clip off the vacuum advance arm, remove the 2 screws on the vacuum advance cannister and pull it out of the way
07-21-2007, 02:21 AM
thanks m j thats the pics i needed i couldnt find it anywere online. I will take it apart tommorow. Thanks again.
07-21-2007, 03:39 AM
you get somethin to work for ya there big guy?
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