Intermittant Starting On Custom Build

[1STMP]

Hard to explain and possibly hard to
diagnose. Please put your thinking
caps on.
The wiring on this build is totally
custom.
After a first time on the road shake out,
things went well. Idle, temps, oil
pressure good.
Pulled in the driveway and parked.
A few hours later, tried a restart, an
audible click, then nothing.
We've installed a mini starter where
the cable stud barely clears the block
by 3/16".
Could this be the problem?
I've tried searching the forum and
could not find anything that mimics
the problem.
I've no idea where to begin tracking
down how to diagnose as electrical
is my weak spot.
Thru the build this has happened only
a couple times during various build
and test procedures. Always the same
fuse associated with energizing the
coil/distributor.
Any help here would be greatly
appreciated.

 

[vance.dykes]

make sure all grounds are good. i have the mini starter and it very close to the block and no problems there. if so it would arc hard and show the short to ground so on to the other possibility the starter relay make sure if you are using a starter relay test voltage at the solenoid going to starter then at the starter and se what that show's

 

[Darter6]

make sure all grounds are good.

This. Battery in the trunk ? Engine block to body ground ? Fresh paint ?
I ask because all of these have caused starting problems.

 

[vance.dykes]

there have been many new cars with grounds to a painted surface that i have had to grind to bare mettle all grounds .

battery to body / body to engine / engine to fire wall . no such thing as to many grounds for electronic fuel inj,

 

[1 Wild R/T]

Grounds are definitely worth checking... But I've had enough brand new starters & relays that were intermittently open that I'll say don't assume that's not where the problem is..

When you have a no start condition try smacking the starter while someone's holding the key in the start position...

 

[1STMP]

Thanks for the suggestions. guys.
From looking around the battery, cab,
engine, and chassis, there are no
ground straps. Methinks this could
be the cause.
Sent the kid to O'Reilly's for a pack
of five.
Will report back if does or does not
fix it.

 

[Don Frelier]

Some of the new starter relays are not very good.
I would start there.

 

[1STMP]

I checked for a ground from battery
to engine. There is one there. Didn't
see it right off until I lit things up.
The ground runs from the cut-off
switch to a bolt on the bellhousing.
I would assume this set up would also ground the battery to the body.

 

[1STMP]

Some of the new starter relays are not very good.
I would start there.

I don't think it's a bad relay. But I'll
check.

 

[blue69runner]

Grounds and more grounds.

 

[1 Wild R/T]

I don't think it's a bad relay. But I'll
check.

Don is spot on.. Unfortunately so many components that we have known to provide years of trouble free service have been re-tooled offshore and the reliability has taken a nose dive...

I've had so many new out of the box Bosch & Tyco components that work intermittently in the last five years..... If you buy off brand stuff it's much worse...

 

[1STMP]

The fuse that keeps popping is a 15
anp in the coil/distributor circuit.
Replaced the fuse, and the truck starts
up fine. (until the next time it pops).
I placed a rubber cap on each of the
coil terminals thinking it's arching from
the distributor wire to ground on the
coil. Waiting on it to get dark so I can
check for any blue flashes on start up.
The starter relay tested ok.

 

[1STMP]

This. Battery in the trunk ? Engine block to body ground ? Fresh paint ?
I ask because all of these have caused starting problems.

Battery is behind the seat. Has a good
body to engine ground.

 

[1STMP]

Done troubleshooting for the night.
Going to test the alternator (internal
regulator, single wire) tomorrow.
Also ran the engine in the dark. No
blue flashes anywhere.

 

[1 Wild R/T]

Failing to crank? Or failing to start? If it's a fail to start but does crank what ignition system are you running?

Just went back & looked at the original post, clicks but no crank... Seriously doubt the alternator is the problem...

So, being intermittent, how often does it act up? Does the click come from the starter? Or a relay? I'm back to get it to act up & smack the starter while the key is in the start position....

 

[1STMP]

Failing to crank? Or failing to start? If it's a fail to start but does crank what ignition system are you running?

Just went back & looked at the original post, clicks but no crank... Seriously doubt the alternator is the problem...

So, being intermittent, how often does it act up? Does the click come from the starter? Or a relay? I'm back to get it to act up & smack the starter while the key is in the start position....

Thanks 1 Wild R/T.
Seems to start popping the fuses
for the distributor/ coil circuit under
mid to low battery voltage. When the
battery is at full charge, the engine
starts fine. I don't think the alternator
is throwing enough juice to charge the
battery.
Drove it for about 5 miles tonight with
the lights on. Shut it down. Went inside
for a restaurant order. (maybe ten
minutes), climbed back in to start the
truck, popped another fuse. Lights
didn't seem be as bright as they
should have been. Drove the 5 miles
back home after replacing the fuse.
Pulled in the driveway, then it died
again.
Waiting on my son now, to check
for what juice is left in the battery
and to see if it popped another fuse.
The ignition system is custom.
I'll compile a list and include in
another post.

 

[moparx]

I'm not a real fan of one wire alternators.
I prefer the 78amp square back, or the 95amp denso units with the proper voltage regulator.
I also like to run an 8 or 6ga wire from the alternator output post to the starter relay.
As you have a custom harness, is it possible the alternator is not getting the proper signal to start the internal regulator to start the charging process ?
the distributor/coil circuit you are describing is it the "start" or "run" circuit ?
is it possible the wire gauge used is too small, causing excess resistance to pop the fuse ?
Just thinking out loud here.

 

[1STMP]

Tracked it down to the alternator not
charging. Popping the dist/coil fuse
do to low volts/increased amperage while cranking.