HP 500 Ignition Module -failure
 

anyone have one of these ignition module's let go? '99 HP500's engine quit while cruising - no spark - swapped out box from SB engine & fired up? $200 bucks for a new one?? Was thinking of going with MSD but do I still need this ICM box #840130??

Re: HP 500 Ignition Module -failure
 

Is there a rev limiter built in to this component.

Re: HP 500 Ignition Module -failure
 

Yes,
the rev limiter is built into the module,
.........and don't you just love where the
mercury engineers decided to mount it,
:rolleyes: :rolleyes:

Never had a module go bad, but
lost a coil last year.

Re: HP 500 Ignition Module -failure
 

I bought a Crane box to replace mine. $270. from Summit.

Re: HP 500 Ignition Module -failure
 

I had faulty distributor module fail on my EFI motor when I got it. After I installed the motor, and tried to fire it for the first time, my pride and joy simply refused to generate any spark. After some troubleshooting, I eliminated the ignition coil and my FAST fuel injection computer as the culprits. The engine builder overnighted me a new distributor module. A 5-minute swap job later, and she roared to life. I ordered another spare ($90) and keep it with me...

Re: HP 500 Ignition Module -failure
 

any idea what the rev limiter is set at stock ? '99 HP 500

Re: HP 500 Ignition Module -failure
 

5350rpms or very close to it.

Re: HP 500 Ignition Module -failure
 

Had the same thing happen to me TWICE on the same motor, make sure you change the coil, it will run for a while then when it gets hot it shorts out and will take out the module again, learned this last year the hard way. I now have the Thunderbolt IV ignition module, did away with the rev-limiter.

Re: HP 500 Ignition Module -failure
 

I did notice oil residue around the coil - could this be the culprit which caused the problem?? My tachs read 5400-5500 @ WOT are they off? or have these boxes been changed/reprogrammed??

Re: HP 500 Ignition Module -failure
 

now I'm wondering if I've been against the rev limiter all this time & thats what fried the module??? :(

Re: HP 500 Ignition Module -failure
 

Sometimes they just go bad. I've replaced quite a few.
They're still cheaper and more reliable than an MSD IMHO.
Gary

Re: HP 500 Ignition Module -failure
 

From past experiences I would just stay with the stock ingnition system. With that system you have the revlimiter and knock sensor to protect the motor. Switching to MSD you spend more money with more potential problems and is not as dependable.. If there is oil leaking from your coil I would replace that as well.

Re: HP 500 Ignition Module -failure
 

......I couldn't agree more with the last two posts.

Re: HP 500 Ignition Module -failure
 

I THOUGHT ON THE 99 HP THE REV LIMITER WAS IN THE OTHER BOX(805443)?? IN FRONT OF THE MODULE

Re: HP 500 Ignition Module -failure
 

The 805443 is the knock control module( outer),
the 848821t2 ( inner) is the ICM, where the rev. limiter
resides.

here's a pix.

http://www.mercruiserparts.com/Show_...RU+0L001772%29

Re: HP 500 Ignition Module -failure
 

Ok So If You Unplug The Knock Sensor The Motor Will Run??

Re: HP 500 Ignition Module -failure
 

Is the Crane box a marine box for $270.00?

Re: HP 500 Ignition Module -failure
 

Here's my issue - my motors made peak HP @ 5400 on the dyno, so I would like to spin them @ least 5400-5500 - don't really want to drop the coin on MSD (not to mention the reliability factor) here's a question would I have known I was on the limiter or does it retard timming too prevent overreving???

Re: HP 500 Ignition Module -failure
 

Ran-Dom 32,
I ran my 1998 HP 500's on yhe dyno with the thunder bolt V module and the limiter hit at 5450 rpm and it was very noticable. I have two modules if you are interested, I went with the crane boxes. Jeff

Re: HP 500 Ignition Module -failure
 

Now I'm even more confused - 5450 ? I thought it was 5350? - how much you want for them? & what benefit was it going to the crane boxes?

Re: HP 500 Ignition Module -failure
 

does anyone know if you can run MSD boxes with the stock merc distributer??

Re: HP 500 Ignition Module -failure
 

If you don't want to go with the Merc unit, I would definitely look at the Crane box!
It has several different timing curves, and a fully adjustable built in rev limiter! You just turn the little dials to what you want.
And, it's fully potted, so moisture is not an issue.

I'm still running the Merc, but when/if it ever breaks, I'm going Crane...