Timing,starters and voltage drops,

[canuckcj5]

Question for the masses,

My cj has developed a hard start since I did the cam gears and it's like a dead battery, I'm not sure what's really going on but, when I start the truck my voltage drops from 13.5v to 11.5v I'm not really sure if Mabey the truck has too much timing, Timing is at 8* BTDC as I am running a mild rv cam in my amc 360, when the truck is hot, I barely can start it, I usually have to get it jump started, I don't get any weird voltage drops when other accessories come on,(elec fan,lights.etc..) anyone have a similar issue? I was going to replace the starter with one I have sitting on my bench and see what happens, battery holds a strong 13.5v so I dunno


Thanks,
Nick

 

[Torxhead]

A dead battery can be caused by a couple of issues. You might want to first consider a voltage drain of some sort. If you disconnect the positive battery cable from the battery there should not be any spark between the cable and the battery terminal when they touch back together.

 

[Lumpy Grits]

Have the starter ck'd for amp load-High drain is a sign of die'n starter.
How old is this battery? Chg it fully and have it also ck'd under a load.
Also have your alternator ck'd for amp output.
Notice--I said 'amps' not volts-You need to take those 3 items to a store like NAPA and have them ck'em. You want to now what reading they each give.
I would start with the battery--
LG

 

[canuckcj5]

I made a little vid of the voltage drop on startup, the alternator was just rebuilt, battery was on slow trickle charger for most of the day, I gonna replace the starter today and see if that helps at all with one I have, anyway

Video

 

[Torxhead]

Yeah, the voltage drop is not bad. What some guys do is run at least #2 wires for the battery and hook up an additional ground wire from somewhere close to the starter to the battery negative since that is the biggest battery draw. Also use marine type copper or brass terminals for both the wires and battery.

 

[Hedgehog]

Not seeing a problem there. Under starter load the battery is working hard to turn the starter, as soon as the engine fires the alternator kicks in and returns the system to +13 volts, seems entirely normal to me. Now if the drain continued or if your CJ didn't start after running for a while you'd have a problem. You wrote that you added a "mild cam". Timing won't effect your start up, I run 12* in my 360, but a cam just might. Cams effect compression load, if like Lumpy said your starter is getting a little weak and we all know hot electronics will show a weakness quicker you just might see the problem exactly as your experiencing now.

 

[Lumpy Grits]

I made a little vid of the voltage drop on startup, the alternator was just rebuilt, battery was on slow trickle charger for most of the day, I gonna replace the starter today and see if that helps at all with one I have, anyway

Video

What do you call a 'trickle chg'? How many amps going into the battery per hour. A few hours ain't gonna do much it it's under 10 amps a hour.
Is this a wet cell battery? if so-CK the H2O level.
Charge that battery overnight on a automatic charger.
Again I ask---How old is this battery??
The battery is the heart of your system. And it's biggest weak point---
LG

 

[Old Dog]

I must be missing something, all seemed normal to me.

 

[Lumpy Grits]

One other thing-
Take the battery NEG(-)lead that goes to the block. Move it to the top mounting bolt of the starter.
Make sure ALL of your GND(-)connecters are clean(no rust)/dry and TIGHT.
LG

 

[Hedgehog]

Old Dog - I agree with you until he wrote:

Question for the masses,

when the truck is hot, I barely can start it, I usually have to get it jump started,

Thanks,
Nick

Not starting when it is hot adds another kink in the story. Now I don't know if it won't "start" or if it won't turn over or if it turns over but won't start without help from another battery. All point to either the need for a new battery or tired starter. Then again it could be as simple as a burnt starter solenoid. But the voltage drop on starting seems entirely normal.

 

[Woolyworm]

Isn't there something about a timing retard that is supposed to happen to help with hot starts? How is the cam change tied to all this? Hmm


Wooly

 

[Lumpy Grits]

Your think'n about aircraft.
LG

 

[Hedgehog]

Wooly - Depending on the compression and the cam itself, some cams can make it more difficult to turn an engine over which would reveal a previously unknown starter/solenoid/possible ground problem. I've also seen it where a corroded battery post can create a diode effect where electricity can flow one way and not the other. Occasionally surprisingly clean looking terminals can get a fairly thin coating that acts like this. It's been a long time since I've seen that situation though.

Shutting off the engine will take all the advance out of your engine. Both centrifugal and vacuum advances go away.

 

[Woolyworm]

http://www.jeepforum.com/forum/f8/b...rted-1340134/#/forumsite/20623/topics/1340134


Wooly

 

[Hedgehog]

The linked post is a great one for dealing with electrical connections. I use, have bought and thrown away many of the wire end crimpers shown. Believe me, spending a lot of money on crimpers doesn't guarantee a quality crimp. After being frustrated with the cheap crimpers I paid stupid money for what looked like a great tool .... NOT .... After reading that post I spent about $10 on a big ol' squeezer at Auto Zone. Best buy I ever made for wire work.

 

[Lumpy Grits]

I only use insulated crimp terminals for quick field fixes.

I prefer un-insulated terminals(ring type as much as possible). After I crimp, I will solder the connection and then use heat-shrink insulation.

LG

 

[SCSEAJAYSEVEN]

If you have what is known as a "RV" cam, then it is made for low end torque, slower RPM, more power at slower rpms.

You can almost throw away a timing light with any cam that is not of stock grind. I have one of "those" cams in my AMC 258 i6 / 4.2l , and it just will not run right with the stock timing setting. Start off with tuning by ear, you can use a vacuum gauge and a tachometer to get close. Run it down the road, and readjust the timing so there is no spark knock under slow speed load.

Mine still wants to start slow in initial startup of the day, but any other start during the day is perfect. You just have to play with the timing setting until you get the "right" setting for your engine.

All the other posts in this thread are important also, about the correct wiring and clean and tight connections.

Sometimes an engine with a non stock cam will have it's own qualities that you have to learn...

 

[tarry99]

Question for the masses,

My cj has developed a hard start since I did the cam gears and it's like a dead battery, I'm not sure what's really going on but, when I start the truck my voltage drops from 13.5v to 11.5v I'm not really sure if Mabey the truck has too much timing, Timing is at 8* BTDC as I am running a mild rv cam in my amc 360, when the truck is hot, I barely can start it, I usually have to get it jump started, I don't get any weird voltage


Thanks,
Nick

Sounds more like a Timing Issue.............Probably not Ignition if it is set at 8*, Since you were under the front cover........do you have the marks on the timing gears lined up?........After you replaced the Cam did you have to change the location of the distributor to get it to run?
Some aftermarket Cam gears have an offset plug / Pin that allows the cam to be installed either retarded or advanced by a few degrees........do you have one of these gears?

 

[Lumpy Grits]

I made a little vid of the voltage drop on startup, the alternator was just rebuilt, battery was on slow trickle charger for most of the day, I gonna replace the starter today and see if that helps at all with one I have, anyway

Video

You are shown'n volts-What you must do is to fully charge the battery(overnight)and have a pro, load test it for AMPS. Amps are what turns the starter motor--
How old is this battery?
LG