Acewell rev counter problems - help needed

[JAMIE B.]

I'm having problems with my acewell 3250/3994
Rev counter works fine when you start up and idle, but as soon as you rev the car up to put off the battery warning lamp and let the revs die down its then reading double the amount of rpm that it should !

Ive set the rpm to 0.5 in the rpm menu and the yellow coil wire terminates on the coil negative terminal
Im running a mg metro 1275 with electronic lucas distributor and a 143 coil

Any Ideas ???

 

[Phaeton]

Ive set the rpm to 0.5 in the rpm menu and the yellow coil wire terminates on the coil negative terminal
Im running a mg metro 1275 with electronic lucas distributor and a 143 coil

Any Ideas ???

Jamie, That's all I had mine set to along with MattBlack's & it worked fine, have you tried to disconnect the charge light from either end & try again. Other than that I suspect a faulty unit.

Alan...

 

[JAMIE B.]

I have actually disconnected the alternator plug and bridged the 2 heavy browns and the acewell ran sweet also when I disconnected the charge lamp, it went ok too

Having no charge lamp kind of defeats the point of having it tho

Kind of thinking that it could be alterntor interference ?

Maybe some kind of suppression device needed ?

 

[Phaeton]

Having no charge lamp kind of defeats the point of having it tho ?

Your also going to end up with a fried alternator & a very flat battery.

I think you need to go back over the wiring & make sure you have it connected up correctly, that your live feeds are coming from the right place. Try bringing the live feeds direct from the battery temporarily. What are you using as your charge light?

Alan...

 

[JAMIE B.]

Charge light wiring - brown/yellow wire from alternator and white feed originating from ignition switch both to 2 watt warning lamp

Have just tried disconnecting white feed from lamp and came straight from battery + still the same !!?

 

[Phaeton]

Try earthing direct to battery as well??

 

[JAMIE B.]

only earth involved is the grounding of the alternator to engine then in turn to chassis then to battery, that side of things is fine.

So looks like Im still sctraching my head

 

[Phaeton]

It's a while since I did one but I thought the Acewell had 2 earths on it.

Alan...

 

[JAMIE B.]

Acewell has 1 earth ring terminal which branches out to the computer, temp sensor and the fuel sensor

At least this one does anyway

 

[funbuggydave]

Thinking about this the interference is almost certainly caused by the alternator for whatever reason, but whether its being conducted through the power line or sense line is another thing.
If you have a second 12V battery try powering the dash from this, with the -ve of this battery also connected to the chassis/-ve of the main battery.
If the problem persists then the interference is coming down the signal line, not sure how to solve that one, but some form of suppression on the alternator may help.
If the problem disappears then the interference is being conducted down the power supply lines, in which case it may be worth using an inline filter that you would use in a car audio setup for a head unit in the supply line to the dash, again alternator suppression may do the trick.
Hope this helps
Dave

 

[JAMIE B.]

Spoke to chap at acewell today, alternator interference is a common problem with this unit, interference running down lead to rev counter (yellow lead).
There are 3 solutions as follows.

Option 1 : Scrap yellow lead and use tv or satellite co-ax cable and ground cable outer to earth

Option 2 : Use resistor which came with acewell in line with yellow cable

Option 3 : wrap yellow cable round coil to dizzy ht lead 4 times

All of the above require acewell rev counter setting to be set at 0.5

Resistor set up didn't work for me so I settled for wrapping round coil ht lead and then covering with heat shrink and a little aluminium adhesive tape for screening - sorted !

 

[esdebe]

Humm, may sound strange but when you rev the engine does it interfere with digital teresrial TV? I had that problem and my neghbour complained, it turned out to be interference form a new set of bosch HT leeds, I put back on an old set and all was fine...

Before I found that the HT leeds were the problem I replaced the suppression capacitor on the alternator, so it is work checking that the suppression capacitor is there, and that it is working.

Simon

 

[JAMIE B.]

There is a suppression capacitor on the alternator, strangely enough I've got bosch leads too ! No digital tv issues though.