96 Challenger Starter turns for 3 seconds then stops (not the starter)

[Spimothy Leary]

ok dropped the engine back in my 96 challenger project boat this afternoon.
Dess beeps twice, when you engage the starter button, it turns over for about 3 seconds, then stops, i can't get it to engage for more than 3 seconds or so.

so, started the process of elimination, and i'm not liking whats "left" on the list, maybe there's something I overlooked.

ran power to the starter itself, turns over and stay's on just fine, so its not the starter
replaced dess post, just fine & dandy
shorted the little switch under the throttle/reverse, no change (reverse appears stuck, i'm going to replace the cable)
replaced solenoid inside ebox... nothing different,
checked the hots/ground's all seem just fine, fuses too.

i'm kind of down to a possible bad MPEM... unless 'm overlooking something obvious.

since I really don't know if, or how it was running at the time of its demise with the previous owner, I really can only do the obvious, diagnose, check and recheck, but the engine was shot, and there was an exhaust leak, so it seems like it would be weird for it to have MPEM issue AND blow the engine at the same time, but well, u never know. My best guess is that the exhaust leak caused the motor to get water in it, he left it sit for just long enough for it to completely rust up, the only thing I salvaged from the engine was the cases.

so.. any thoughts/suggestions to help turn around my day ?

 

[Dr Honda]

When it's cranking... does it stop, and give you a single beep after? Normally (with your description) it is a weak battery. The problem is... when you are cranking it with a load... the voltage drops, and the MPEM resets.

 

[Spimothy Leary]

battery is brand new, was fully charged as of Tuesday or so, i can always do a quick load test on it.
certainly worth checking into, and charge it again, its an Excide 24 battery, but i have bought bad batteries before... u never know.

but no, it cranks and then just fizzles out, no beep after. However, if I just run a direct start switch from the battery to the starter, it keeps cranking, which is why i know its not the starter, essentially i bypassed everything there.

i'm not 100% on this, but I can check it in the AM, since you mentioned the reset, i'm pretty sure (not 100% sure) that i had to disconnect and reconnect the key every time to get the 2 beeps to try starting again, so maybe the mpem is resetting.

 

[bigtexan99]

Does your boat look/sound like this video? http://img17.imageshack.us/img17/2117/lv8.mp4

My boat was doing that and it turned out that I had fuel in the cylinders. To blow out the fuel, remove the spark plugs, GROUND THE SPARK PLUG WIRES ON THE GROUNDING POSTS, and the crank the engine. If there is fluid in the cylinders it will come shouting out like a fountain.

Then, reinstall plugs and see what happens.

 

[Spimothy Leary]

there is no fuel in the cyl's its a fresh rebuild. bone dry.

again, if I run power directly to the starter, it will crank all day.
if I hit the start switch,,, i get 3 seconds... no more....

what else can it be besides the mpem (and what I eliminated already in the OP)

 

[Dr Honda]

Don't do a regular load test. Just put a volt meter on the battery terminals, and crank like normal. If you see the voltage drop below 10.6v, then the battery is bad. (I've seen batteries that were bad out of the box)

BUT... if it stays up, then I would start by removing every cable, and cleaning every terminal. AND, possibly... replace the main cables. Cables can go bad, by building high internal resistance. SO... crank it a few times... letting it stop... and feel around for a warm/hot cable.

Finally... jump across the solenoid. You could have a bad contact internal.

 

[Dr Honda]

Interesting point about fuel in the jugs, and a fresh rebuild.


1) Have you tried cranking the regular way with the spark plugs out?

2) Have you checked the compression? (To make sure the proper base gasket was used)

 

[Spimothy Leary]

boat is running fine, actually not sure what the original problem was but we installed a 2nd ground to be safe and she's purring like a kitten, then I had an exhaust leak due to a bad surface on the pipe where it clamps to the lower, but I have pipes in stock so i just grabbed a new one, and that was easily resolved too...

had it out saturday for a stretch and it ran great...

but whats the dealio with the battery draining ?
2 weeks and a brand new battery was dead....

i've been told this is a known problem with these and that a battery disconnect is a solution...either that or leave it on a tender all the time...

thoughts ?

 

[LouDoo]

Have you tried replacing the cable from the solenoid to the starter? Reading over the posts by process of elimination that's what it sounds like to me. Could be internal corrosion.

Lou

 

[Spimothy Leary]

no i haven't, but I could,,,

that would cause a battery drain ?

 

[griz400]

At work i have a cable of like 10 guage wire and its about 8-9 ft long, has a battery clamp on both ends like on a battery charger, and its like a tool, clamp from battery, to solenoid, if that didnt do it, calmp from solenoid to starter, also from ground side battery to engine block, also make up other longer jump wires of lesser guage wires to check other things, -- note, like a voltage drop, if your battery shows say 12.5 volts, well b+ wire on solenoid should show same, and also b+ wire at starter, if voltages show lesser amounts, then this is a voltage drop, and cables in that case would be problem... note though, that the main battery bround at lower side of engine is sometimes the root of all evil

 

[LouDoo]

no i haven't, but I could,,,

that would cause a battery drain ? View attachment 11035

A bad starter cable wouldn't drain the battery because it's on the other side of the solenoid.

Lou

 

[howie099]

Is the battery even charging when the boat is running? The startor could be bad or the voltage regulator. Also you could have like a power antenna left on draining the battery, the radio or some other stuipd like that. You can just remove the smaller gauge wires from the battery and keep just the starting cables on to rule out if the somehting connected to MPEM is draing the battery since almost all of the power accessorys go throug the MPEM or jsut remove the fuses and and see what happens.

 

[Spimothy Leary]

well, there's a harbor freight right near my office so i grabbed one of these battery disconnect switches for $8.



i'll get it up to full charge then disconnect and see what happens

the drain occurred during a 2 week sit in the garage

but with a battery disconnect, i can eliminate all variables
its possible i had left a switch on tho