RSRoy

My brothers 4x4 Sapphire had some boost issues a while ago. The car had too much boost and we couldn't get it down. Also the boost was fluctuating a bit between 1 and 1.3 bar (14.5 and 18.9 psi) when asking full power.

We did some parts swapping to eliminate verious causes and thought we had nailed it down when we fitted another amal valve of a friends car. With this amal valve the cars boost went down to 0.7 bar (10.1 psi) and thus we could give the actuator more preload to get the boost back on to 1 bar.

Because the amal valve that was fitted was borrowed we had to give that back. Got an amal valve of someone who said it was working correctly and fitted that on to the car. The boost problem however was not cured so we assumed that amal valve was faulty. I now had my own car back at home so I removed my amal valve from my car and fitted that to my brothers. Again still the same boost issues. Boost wouldn't come any lower then 1.3 bar and keeps fluctuating when on full power. In my car my amal valve works correctly and my boost is steady.

We asked our friend to borrow his amal valve again to see what my brothers car now did with his amal valve. Fitted it and did a testdrive and the boost was just perfect again.

Who has any idea what is going on here? Are the amal valves all the same or are there some differences?


For the record, it's a 4x4 red top Saff with a stage 1 chip and -31 actuator.

andym

iTrader: (1)

Check the Amal valve jets are the same or even fitted.

RSRoy

They look the same with the bare eye. But how small can the differences be, I mean I can't see if they are 0.5 mm smaller or something

RSRoy

Had a look 2 amal valves we had laying in the garage.

The jets are between 2 and 2.5 mm.

But these are amal valve that weren't working on the car. Next week I have the opportunity to check the jets on the amal valve on our mates car (the valve that my brothers car was running perfectly with).

andym

iTrader: (1)

As far as I know, you should set your actuator to half cover and jet your Amal valve to archive the desired boost level, your ecu then controls the boost level by oscillating the Amal valve. If you drive the car with the Amal valve disconnected it should only have a small amount of boost, this is the fail safe as the ecu will de-energise the Amal valve if it senses a problem.
If you pre load the actuator too much you have no safety margin.
The above is how I understand it and no doubt if incorrect somebody will let you know
It may be worth talking to your tuner. Try Tony at Turbo Systems as he will definitely be able to help. Screen name turbosystems

Turbosystems

iTrader: (5)

your friend amal valve is faulty ie doesn't work hence why you only have actuator pressure related boost pressure when you fit your mates. You could quite simply have just unplugged the electrical connector of your brothers to achieve the same
yours and your brother amal valve sound as though they are fine
your problems lie elsewhere on your brothers car
it may well be the boost map

andym

iTrader: (1)

Tony You should have a light like Batman

RSRoy

Thanks for your explanation Tony. I will try to unplug the electrical connector and see if the results are the same with our mates amal valve

I'll post an update here as soon as I know more.

Turbosystems

iTrader: (5)

you can try unplugging all three amal valves to see what happens
I suspect with yours and your brothers your boost will drop to actuator pressure
and with your mates the boost won't alter

RSRoy

I'll try with our own amal valve tomorrow. Won't have access to our mates amal valve till next week. But as said, I'll keep you posted

MARCOSWORTH

iTrader: (24)

Try what Tony says Roy and we'll see what my amal will do next week

BTW jets are at 2.2mm i'll bring a ecu along mate

RSRoy

Well we did some testing yesterday but didn't really found the issue.

Swapped ECU's, Amals, chips, etc, no improvement.

Then we removed the original (new) 2 bar map sensor and fitted a 2nd hand one. All problems gone! Fitted the original map sensor again, no problems at all anymore...

YBJ

iTrader: (3)

I suggest you do an air leak test to the car. Pressure the whole intake system to 2.5 Bar and see if there are any leaks.

RSRoy

I don't know if anyone near me can help us with that. Don't have the ability to do that myself.

MARCOSWORTH

iTrader: (24)

Check your wiring connectors also Roy, i think that's where your problems are

RSRoy

I leave that up to Nick, electronics aren't my favourite thing

wolf cosworth

Hi Roy,

pressurizing the system I made myself with a plug ( aflsluiter regenbuis of zo gaatje erin en ventiel op aangesloten ) in the inlet hose from the turbo and then regulate your compressor to 2 bar and connect to your system .

You would be suprised on howmany spots air leaks

Steven