If ones working properly on a cossie what voltage is it supposed to give off?!

checking if mines working and its giving off 12.6 as a voltage reading when engines running, and about 1.170(variates) when the ignition is on.

 

That is fine.

FYI - The low voltage is a pulse width that most meters will not read properly.

 

Cool cool, cheers mate

If its giving off a voltage does it mean its actually working thou?! got no-one to check if its clicking when ignition is turned on so gonna go out in a min and unplug the wires with the ignition on too see if it does click or not.

Also a bit confused with how its wired, its got a high low boost switch, and on my old cossie i just spliced the switch into the black and red wire goin 2 amal valve and it worked fine.

On this one the brown and yellow wire going from the ECU to the valve im assuming?! (no16 i think it was) has been cut, then the wire is routed to the hi/low switch instead of the ECU, then a wire from the switch splices into one for the fan override switch?! does that make any sense cos it doesnt to me The wastegate is wound right out so only boosting about .5 bar but dont wanna wind it in to get more boost if the amal valves not working properly

 

If the amal valve clicks at idle then its working.
Take the plug on and off to try it.
(may need to pump throttle on some chips)

Also, make sure your boost switchis ON !!!

Using either wire to the valve is ok !

 

12.6 when engine is running aint brilliant. Should be at least 13.6 if ya alternator is as 14...

I would check the voltage to your fuel pump

Brown yellow is ecu trigger.

Black/red is feed. +volts

 

Really?! Got i hate electrics

Will check the valve in a sec cheers, with the boost switch off you dont get any reading which i guess is right?!

What sort of voltage should the fuel pump be kicking out?!

Will check what voltage the alternator is kicking out aswell!!

Yea thought whatever wire would be ok tis just done a bit weird, would have tought you would have just spliced both ends you cut to the switch, like i did on my old one where as this the wire coming from the ecu pin on the loom doesnt connect to anything, and the other end goes from the switch to the valve so cant see the ECU being able to get a reading at all?!

Glad someones making sense of all this

 

dingy,

A low initial voltage can be caused by starting the engine and not reving it above 1200 rpm. This is perfectly normal.

FYI - The ecu will ALWAYS drop the voltage through it on an output device
and its wiring from a difference of 0.7 volts upto 1.5 volts worst case - still normal !!!!!

To clarify, 12.6 volts measured at the AMAL valve is acceptable !!!

 

Ah yea just started it and let it idle havn't revved it or anything, out i go

Cheers for you help mate just wanna make sure everthings ok b4 i wind the boost up a bit, its a stage 3 t34 so .5 bar is a bit gay

 

If the drop from the relay to the amal valve is 12.6 mate, i would think the rest aint good either as there is no load on the amal valve.

Just been testing a cossie too, no rev's and running 14 to battery and 13.8 to injectors @ 1000 rpm, never checked amal valve tho but ran 13.5 to fuel pump which is decent.

 

dingy, Dont forget NOT all measuring meters are accurate.

 

No mate they are not. But a 200 quid fluke aint bad

 

Think mine was only about £20 so prob sums it up


brb

 

dingy, You and I may have fluke DVM's but not everyone else has !

Ecu's do to a large extent cope with voltage fluctuations without problems.

 

I am not saying they don't simon.

But things like the pump need voltages to flow enough fuel as you know...

 

dingy, Fuel pump is another matter- agreed.
But 12.6 volts at the amal valve with an error allowance of 0.7 to 1.5 volts is ok !!!

 

I beg to differ.

Its ok for the amal valve agreed. But its not brilliant for the car.

Last loom i did ran 14.2 to battery from alternator and 13.9 to all postive feeds, if this is producing same voltages from the alternator then there is issues in the loom regardless of the fact the amal valve is ok. I would imagine the amal valve works of much less voltages, but that was not my point.

 

Your measurements depend on WHERE both probes of the meter are placed.

Any semiconductor driving stage will always drop the voltage by around 0.6 volts.
This is a FACT of electronics using transistors for the controlling device.

If you measure the voltage across BOTH the amal valve wires when enabled
(dont forget it is neagtively switched)
you will get a voltage difference of the size i mentioned when compared to
measureing directly accross the battery.

Also may be more when wiring and connector resistances are included.

If you measure from an EARTH to the non switched positive wire on the amal valve, you will NOT see this semiconductor voltage drop as the ecu switched the negative line.

Hope that makes sense.

 

Makes perfect sense to me.
The issue here is largely where are you taking the earth from?

 

If your talking to me ive got the pisitive probe on the black and red wire connection and the neg on the brown and yellow one.

No clicking from the amal valve on taking it off sounded it like did once but not after

So is it ok the way the switch has been set up and the wire thats supppsed 2 be going to the ECU not going to it now?!?!

Just found out the cars got anti hijack thou which shit me up

 

surely the earth from the ecu is dependant on the earth to the engine then, so if the earth from the the engine and the positive wire for the map sensor will be the the best way.....

By the way i check voltages as the car is started across points and across the main earth for ecu and the positive.

 

When for example checking voltages, any device needs at least 2 wires
or power feeds to drive it - a positive and a negative.

If you do NOT measure as close as possible across the device under test with BOTH probes,
you do NOT get an accurate picture of what is going on.
E.G. Just because you get 13.8 volts on the injectors positive doesnt mean the
injector itself gets 13.8 volts when its working.

Using an injector or any other pulse width controlled device is a bad example as it
pulses so fast you can only measure the voltage across it properly using an oscilloscope.

Also............
If you put the METER earth on the ecu earth and the METER positive on the injector positive,
you are only in effect checking one wire on the injector.
When the injector is powered but the engine is NOT running, the voltage flows
through the injector coil and BOTH terminals become the same voltage.
This does not mean the other terminal is ok.

 

OMG this is getting too technical

So if my amal valve with the switch on isnt clicking its fooked?!

Still not sure bout this wireing thou shouldnt the brown/yellow wire to the ECU still be going to the ECU to be working properly?! or is going from the switch instead and the switch earth enough for the amal valve to work properly anyway?!

 

Was a bad example agreed, but it was an example....was more to do with voltage supplied i guess, but i understand what you are getting at.

All devices need to me measured across the device, this to me is one of the tests to perform in testing voltages in a loom.

 

If you have power measured across BOTH amal valve wires and it doesnt click then yes its fooked.

But to be sure....
TRY disconnecting it and using 2 peices of wire, directly connect it across the battery to test it. It should click if working.

The ecu may not be switching it on so will seem dead.

Its difficult to remote diagnose electrical faults

 

dingy, Not saying your wrong mate !!!

Its good that you do at least test as best you can as you probally dont have a scope !

 

Got a scope mate but can't be arsed to take it with me EVER....LOL

 

Nah thats cool secs helps been much apreciated mate

Yea with the switch on you get a reading but no click, will give the batt test a go in the morning but sounds like its fooked!!!

So is the brown/yellow wire not going to the ECU and just going to the switch ok then?? would have thought it should still go to the ECU?!

Just wanna make sure when i fit a new amal valve and slowly adjust the boost it wont cause probs!!!!

Althou will be getting it set up properly asap just to be safe!!!

 

double post

 

Toe Knee,
Just one thing to recap, some cars are wired so that the amal valve is only powered when the engine and fuel pump are running.
Check the voltages at idle before condeming it!!!

 

ok mate cheers!!! Tried it with the engine running too not just with ignition on and was showing the same value so. Althou the batt light stayed on till i blipped the throttle so could be a power drain somewhere!

 

nice post,,,

i normally say that if its clicks it working

SECS,
good point that alot of people dont think about

 

Right continuing on

Cheers for all the help Secs, looks like its a dodgy connection within the amal valve itself cos it only 'clicks' if u wiggle the terminals, changed the connectors aswell so its deff not them being corroded. Is it possible 2 pull it apart and check inside?! dont wanna do it and break it

Also noticed, in the middle hole theres a white thing Is that right?! or does it mean its been jetted?!