Livorsi tachs acting strange - need help please
 

So, I just had new motors put in my cig. Went from the stock 525sc's (which were 454 blocks) and went to 502 blocks and running TBS blowers at 5 lbs of boost. I am in my break in period right now and I noticed that once the tachs reach 3800-3900 rpm's, they start fluttering and freaking out; actrually going backwards. Its not the motors - they sound and run great. Does this sound like an electrical issue? Ground maybe? I am kind of stumped. The tacjs worked fine before the rebuilds, but now, they work up to 3800 and freak out. What should I be looking at? modules? wiring? grounds? The GPS speedo also does not work. Any feedback or thoughts would be much appreciated. Mark

I said it many times ,,,BUY GAFFRIG , Livorsi sucks !!!!:eek:

Nice approach. I think this issue was covered in many other threads. I'm sure all the manufacturers - Cigarette, Outerlimits, Hustler, MTI, Skater and others would only install the absolute worst gauges in their product - Livorsi.

The only thing I like about the Gaffrig gauge is the glass lense. I dont like any other aspect of their product, but I still wouldnt say they suck. But then again I was probably just brought up properly.

If thats your method of marketing, I suggest you revisit Marketing 101. Promote your product without slamming the competition.

As far as the issue here, there was or is a definate change in what the tach is seeing or getting feedback. If you want to send the tach in to get it tested, let me know and I'll take care of it. I suggest swapping tachs to try it first. If I can be of further assistance, please let me know.

Kirk

I would have to guess its in the wiring. Did reuse the TB IV's or go with new ignitions??????

KIRK,KIRK,KIRK,,,,how many times should we argue about this.
THE ONLY REASON WHY ALL THE BIG BOAT COMPANYS USE LIVORSI NOW ,,IS BECAUSE LIVORSI LIED ABOUT GAFFRIG AND EVERYBODY THOUGHT ITS ONE AND THE SAME !!!!!

THE BEST GAUGE IS GAFFRIG or NORDSKOOK and u know it.
:Whatever:

Stayed with the TB IV's and have the v6m modules.... I was kind of assuming it has to be wiring too, both worked just fine when the boat was brought in for the rebuilds. I just dont know if they share a ground or what is going on up under the panel. any suggestions?

I have heard that is due to slight moisture in the gauge itself.

Would that stand to say they could dry out and the problem would go away? Or should I send these to Livorsi to be tested? It just seems strange the problem appeared right when engines where swapped and they worked just fine. The boat never sat outside, or got wet this winter. And with the gps speedo not working as well (both worked fine when boat was brought into shop) It just seemed to me that it might be related to wiring..... any other suggestions? I really appreciate the feedback.

I think you have a bad ground or loose sender wire somewhere. Pull the plug on the wiring harness by the engine and spread the prongs and clean if needed. Check for loose ground straps or even not connected wires on the engine. I say this because you just installed the engines and now you have problems. I doubt you have gauge issues. The engine can run fine but if the ground to the dash is not hooked up or loose...

Check the grounds on the modules. They have a black ground wire and the module case/mounting plate also needs to be grounded.

Livorsi Tachometers
 

The tachs worked before you changed the engines so it can be one of two things. As Zastrow says it may be a ground. Take a seperate ground wire from the negative side of the tach directly to the battery ground. It also could be getting an interference noise from the blower. Livorsi sells a filter to filter out noise to deal with this problem.

As for the GPS the antenna battery could be bad. If you send them to Livorsi or Elite we can check for any of these problems.

My engines were pulled and the same thing happened. I have not found the problem yet but mainly due to being lazy and the water calling

I had the same problems with Livorsi tachs all last year. Swapped tachs, changed tachs, sent tachs in for testing, redid all grounds and ran new grounds. Still crazy tachs, one side worse than the other. The only noticeable improvement I got at one point was changing spark plug wires. But is still was not fixed. I added blowers last winter, so maybe I need these filters. How do they install?

I had a similar issue last season. My stdb tach would flutter and the engine was skipping at higher rpm's. After a bit of troubleshooting, we found the problem to be a loose ignition module ground.

The tach suppresor goes in line on the signal wire. It is a simple install. Also bad spark plug wires could add to the signal noise on tach and will give it iratic readings.

Can you give me a part number and contact for purchase?

Tried all this and STILL no luck!!
 

:mad:
This is everything we tried:

used an MSD tach generator, simulating engine running, tested good, tachs worked fine to the rev limiter.

Other grounds at gauges were checked; all were good, showed 12.9 volts at each gauge positive to negative.

Also did a sweep test on each gauge by grounding sensors on both motors to a known good ground, function tested normal.
Sytem voltage is 14.2 volts on both engines idling.

Hooked a known good ground wire to every ground possible on both engines, did a test run after each connection.....

Tachs work great right up to about 3800 RPM, and they both STILL start fluttering and go back down toward zero.
I am really at a loss here....
Anything I am missing here, this is really baffling me here, more suggestions would be much appreciated....

Thanks. Mark

This may seem like an odd way to check your tachs, but see if one of your friends wouldn't mind putting YOUR tach in his boat. If it works (which, from your MSD generator, would suggest that it will work just fine), you have ruled out the tach. One of my boats had a similar problem where the tach and water temperature gauge (but none of the other gauges) were fluttering/spiking and we checked everything ... except a couple months later the alternator literally fell apart ... the long screws that held the cases together had vibrated out. Made a mess of the alternator, but, when it was rebuilt, the gauges quit their eratic traits.

Did you use new spark plug wires with new engines or reuse the old ones????

What are the ignition modules bolted to????

X 2, start the engine up then go back and wiggle the main power wire harness and watch all the gauges and see if they wig out at all or some times the engine will die.

If the new engines have fresh paint, we always removed a spot to paint where the V-6 module are bolted to the blocks. Did you change anything in your main grounding set up from the batteries? How about the ground jump from engine to engine?

Brand new spark plug wires. It did it right off the bat with a new pair of taylor's on there. Even replaced those Friday with a new set of MSD wires that have a lower resistence rating....

Factory location, and they are grounded, paint is not an issue.
No loose wires, or grounds, we checjed every one and polished each one up.....

We did this too.... well not the wiggling it while it was running but we cleaned each prong and spread them out a little so they would make a better connection....

What is strange here, is this seems like the tachs are getting some kind of "interference" at the same time, at the same rpm.... what could cause that?/ We are starting to think about the alternators, maybe disconnecting the purple wire from the alternators, and see if it is cooming from them....

We have had the Mercury manual out for the last two days following the entire wiring diagrams.... We are running out of things to look at.... but SOMETHING is causing this!

I will try wiggling the cannon plug while motors are runnning and have someone watch the gauges this morning.

Please keep throwing ideas our way please! I appreciate it!

We checked that... paint has been removed were the modules are bolted up and nothing else has changed. This was a removal and re-installation by a builder. The ONLY thing different is the blocks are 502 blocks now instead of 454.
Engine to engine ground jump is the same too...

Progress made!
 

We disconeected the alternators from the system entirely; removed the plug and the wires connecting to it... and the tachs worked..... BUT, the alternators work (are charging at least) because the gauges read 14 volts when connected and 12 when they are not.... looks like this has to be something in the harness to the alternators? the purple wire maybe?

Any thoughts around this? maybe an explanation of the alternators figure into the system? Somehow they send some kind of signal or interupt at about 3800 rpm that make the tachs goof out when connected. Again, thanks in advance for any feedback.

I don't know a solution, but at least you are getting it narrowed down.

Make sure 5 and 7 plug wires are not running right next to each other in the wire looms. They need to be seperated by at least 1 other plug wire.

My next try is to run a ground wire from the dist. cap screw to a knwon good ground. I've been told the distributor grounding can cause this problem.

BT :cool:

That is a good one could be some paint on the block at distributor try reseting the timing, turn the dist a bunch of times to get a good seat, I have had to do this before.The purple wire is the ign feed wire out of the alt, I guess if a diode or something is bad it could do this but i have never seen or heard of something like this, But the other part of me says all you are doing is unhooking the ign system main power, But i could be wrong becouse it worked. Did the wiggel test do any thing? What is the temps of the alt, From what I have seen most run 120- 150 degress But I have seen them up to 290-300 in less then too min.

By unhooking the alternators you lower the system volts by 2-3 volts and that alone can make a big difference because of the less amp draw on each circuit.
Hook it back up and check for A/C voltage out the back of the alt if it is more than .5 volt replace it.
Also did you put in new pick up coils in the dist, I have seen this cause a few tach issues before.

I will be down to the lake this weekend delivering the Fountain if you don't have it fixed yet and let me know maybe I can take a quick look.

Thanks John, I appreciate that.... i will be back down Friday night and doing more testing on it with my buddy Saturday morning.... I am in the same cove as the fountain you are delivering... Condos right across the cove, Cigarette is at the the end of the inside dock... Third from last slip... the very end slip is a 36' and always empty, feel free to pull in there. I will probably be there, would like to meetyou and say hello if nothing else!

I tried the wiggle test withthe cannon plug, it seems all good. But from the responses, I need to check the 5 and 7 plug wires in the loom, Alternators have not been changed probably in the last 7 years at least. I will check with Mike, the previous owner. I guess its possible they are bad even though they are charging the system? I also notice the volt meter on one of the motors kinda flutters a little and doesnt hold true like the other, but it has always done that.

Mark

Give me a call on Friday and let me know we will be leaving about noon.

Will do, thanks!

more testing done, and STILL having problems.....
 

Well, we did more testing this only to leave me even more confused. We found that disconnecting my alternators completely from the system made my tachs work just fine. So we swapped them out with the alternators from my buddies Fountain (same exact alternator/part #) and they still fluttered and fell back towards zero at 3800 RPM!! We also ran a known good tach directly to the coil and it worked fine.
Then we narrowed in on the harness to the alt's and the wiring to the tachs in the dash... ran known good grounds, signal, and power directly to the tachs with no improvement.

I spoke to Livorsi and they suggested I try a couple new tachs, ones with metal cases... mine are plastic. They seem to think it is interference/ radio frequency interference stuff that maybe the better cases might prevent. I think its a reach but bought a couple to try out. They should be here tomorrow. They are working with me so I cant complain. Said they would take them back without the resotckinig fee if they still dont work. The bottom line is the tachs were fine before the engine rebuilds, and the only thing different is the blocks (went from 454's to 502's)... I cant understand what could be different now that someohow some freak signal is being sent out to interfere with the tachs??? The alternators have me very curious.... but the wires going to them are all good.

Any other suggestions? Much appreicated fellas.

Could try this............
http://www.lonestaraviation.com/prod...nator%20Filter

That is a good idea. also is there any chance that you went from a resister type spark plug to a non resister? I am sure that you are not running the same plugs if you went from NA to blown

http://www.ngk.com/sparkplug411.asp?...esistor&mfid=1

[IMO] You need to seperate the engine from the helm wires, If you can find a new cannon 10 pin wire harness plug from a dealer that might have a good old one laying around in the back of the shop area somplace, You could plug it in and and make up a small seperet dash on a borad of some kind and install a IGN key switch and a tack and what ever eles gauge you want to hook up to it and wire it up and go run the boat and see if it still does it. This way you will know if you are trying to fix the engine, or the wires to the helm or the helm gauges them self. It just makes it easer to find what you need to look at to start fixing. I do the same thing some times when I am trying to find a fuel problem, Seperate the boat from the engine, It so much easyr, Hope this helps if you want to do it good luck.

X 2 on the plugs, By the way what plugs are you running in the engine right now? [IMO] There just seems to be less problems with NGK spark plugs.

Did you check the 5-7 plug wires in the loom? I had the same problem and that helped my situation. I ran the tach off a seperate battery and ran a seperate wire directly to the tach from the coil and it acted the same. Went up to about 4k and all was fine, as I increased rpms it would hold there then fall to zero. Went threw a couple of new tachs with the same results. For the rest of the season I just lived with it. The next season I was looking over things and I noticed that 5 and 7 were running next to each other , seperated them and all was good. On the 90s GM trucks they would set a code in the ECU for having the wires ran together.

I did check the wire looms and ensured that 5 and 7 were not running right next to each other. I am also curious about the spark plugs myself. I know the builder put new plugs in but I am not sure what type they are, I will check tomorrow when I am down and into it again. The motors were already blown before so uit wasnt a conversion from NA to blown, but that still doesnt mean non resistor type plugs are in there.

I haven't gone as far intot eh wiring as boat teck suggested but it looks like that needs to be the next logical troubleshooting step, thank you for the feedback.

Any more suggestions? I really appreciate it guys.