Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 13 October 2007, 22:28:35

Title: Please please please help me fix...
Post by: JamesV6CDX on 13 October 2007, 22:28:35
... my rear multiram  :'(

It's just refusing to work, it does not move when blipping the engine or revving it hard, or at any other points.

Things we know:

1) The mechanical multiram itself and the actuator are totally fine - guaranteed.

2) The Vacc Tanks are both storing a good vaccum - also guaranteed.

3) Tech2 can actuate both rams several times with the engine off, so it's storing a good vac.

4) No ECU fault codes are stored (at all).

5) If you plug the front actuator plug into the rear actuator, the rear one will then operate at the times the front one should (to be expected).

6) If you start the car without the rear multiram plugged in, the EML comes on, and goes off when it's plugged back in.


Please offer any advice if you can, this little fault is really starting to annoy me!

I know it's not a vital component, but I have a really nice car, so ideally I want it working.

All suggestions welcome :y

Title: Re: Please please please help me fix...
Post by: ffcgary1 on 13 October 2007, 23:41:09
Interested in this thread myself james as mine has just packed up as well, although i have not had a chance to have a look at the reason why yet. :(
Title: Re: Please please please help me fix...
Post by: Kevin Wood on 13 October 2007, 23:50:38
I'm stumped on this one. You've proven everything up to the output on the ECU is fine, and if the ECU output was dead you wouldn't be able to actuate it with a Tech2.

Have you checked the ECU to see if it's been chipped? Only thing I can think of is that it's got a non standard chip and they've broken / modified the multiram behaviour.

Kevin
Title: Re: Please please please help me fix...
Post by: JamesV6CDX on 14 October 2007, 01:22:26
Quote
I'm stumped on this one. You've proven everything up to the output on the ECU is fine, and if the ECU output was dead you wouldn't be able to actuate it with a Tech2.

Have you checked the ECU to see if it's been chipped? Only thing I can think of is that it's got a non standard chip and they've broken / modified the multiram behaviour.


Kevin

Hrmmmm....

While what you say seems logical, I hope it's not the case

I certainly doesn't drive like its been chipped, I've driven quicker 2.5's! This one, while fantastic at higher revs, and will achieve high speeds, is pretty gutless at lower revs.

Now you mention it....

Wonder if it's been tweaked for top end, or something silly

I guess I could get another ECU as a test... or open this one up and look at the chip...

I might have to show the car to someone to get a second opinion .. make sure I'm not being a complete daftie over something...

Title: Re: Please please please help me fix...
Post by: Kevin Wood on 14 October 2007, 01:45:28
Well, you've proved the ECU can operate the multiram if it needs to so it's deliberately not doing so. The only reasons I can think of are that it's in some sort of limp home mode (but you've resolved the fault codes?) or someone's hacked the firmware. Could be that a chip has been fitted and someone disabled the multiram in the mistaken belief that it'd give more power or they were simply hacking things they didn't understand. A lot of chips are produced by cowboys, after all, and it's not easy to reverse engineer ECU code to do what you want.

Got to be worth trying it with a known good ECU?

Kevin
Title: Re: Please please please help me fix...
Post by: JasonH on 14 October 2007, 10:05:24
Can you activate the rear multiram when stationary just by reving? I had an idea in my mind that it didn't always go you need speed or engine load.... or perhaps I'm talking b*llocks.
Title: Re: Please please please help me fix...
Post by: JamesV6CDX on 14 October 2007, 10:11:35
Quote
Can you activate the rear multiram when stationary just by reving? I had an idea in my mind that it didn't always go you need speed or engine load.... or perhaps I'm talking b*llocks.

On my other Omega's, I've always been able to see it working by revving the engine...

Title: Re: Please please please help me fix...
Post by: omegalord on 14 October 2007, 11:53:05
Mine is exactly the same for front and back. If i take the vac pipe off and suck the ram comes in , so the ram is ok , but when conected they dont work. I have replaced the vac tank with a brand new one from vauxhall. So god knows what it is

Matt
Title: Re: Please please please help me fix...
Post by: sounds2k on 14 October 2007, 21:07:34
hmmm I seem to remember something along these lines a while ago and it turned out to be the main vacuum pipe from the servo was worn and therefore not generating enough vacuum .... ?????
Title: Re: Please please please help me fix...
Post by: JamesV6CDX on 14 October 2007, 21:08:35
Quote
hmmm I seem to remember something along these lines a while ago and it turned out to be the main vacuum pipe from the servo was worn and therefore not generating enough vacuum .... ?????

Cheers Dan, I have tried a different Vacc pipe - plus, the one from the servo also feeds the front ram, which works fine.

:(
Title: Re: Please please please help me fix...
Post by: Kevin Wood on 14 October 2007, 21:12:51
If you've got enough vacuum in reserve to run the valves manually a few times with the engine off it should be OK when running. My first thought was the non-return valve because manifold vacuum will take a dive when you open the throttle, but you've eliminated that.

 :-/.... >:(

Kevin
Title: Re: Please please please help me fix...
Post by: Taxi_Driver on 14 October 2007, 21:13:11
Quote
Quote
hmmm I seem to remember something along these lines a while ago and it turned out to be the main vacuum pipe from the servo was worn and therefore not generating enough vacuum .... ?????

Cheers Dan, I have tried a different Vacc pipe - plus, the one from the servo also feeds the front ram, which works fine.

:(

Im stumped as well......visit to MDTM i think is in order..... :y
Title: Re: Please please please help me fix...
Post by: JamesV6CDX on 14 October 2007, 21:14:13
Quote
Quote
Quote
hmmm I seem to remember something along these lines a while ago and it turned out to be the main vacuum pipe from the servo was worn and therefore not generating enough vacuum .... ?????

Cheers Dan, I have tried a different Vacc pipe - plus, the one from the servo also feeds the front ram, which works fine.

:(

Im stumped as well......visit to MDTM i think is in order..... :y

I think I may end up talking nicely to Mark.... I already owe him a few favours/beers  :-[
Title: Re: Please please please help me fix...
Post by: Kevin Wood on 14 October 2007, 21:19:40
Only thing I can think of just to double check is to stick a noid light or similar on the feed to the rear multiram solenoid just to double check if there's an electrical signal there when you blip the throttle.

Kevin
Title: Re: Please please please help me fix...
Post by: TheBoy on 14 October 2007, 22:11:06
Only thing thats springing to mind now, this is probably the newest 2.5 you've worked on the multirams on.  Maybe the ECU is mapped differently, meanin gthe rear doesn't act in same way as earlier ones (eg, it only operates under load).

I need to see if live data monitors the valves....
Title: Re: Please please please help me fix...
Post by: Kevin Wood on 15 October 2007, 09:47:46
Quote
Only thing thats springing to mind now, this is probably the newest 2.5 you've worked on the multirams on.  Maybe the ECU is mapped differently, meanin gthe rear doesn't act in same way as earlier ones (eg, it only operates under load).

I need to see if live data monitors the valves....

Wire the solenoid feed up to a little light bulb and poke it out through the front bonnet seal so it sits in front of the windscreen, then go for a drive and see if it lights?

Kevin
Title: Re: Please please please help me fix...
Post by: Marks DTM Calib on 15 October 2007, 10:25:02
Live data does display the valve operation.....it does take one hell of a blip to get the valve to go on the later 2.5's
Title: Re: Please please please help me fix...
Post by: JamesV6CDX on 15 October 2007, 13:57:38
Quote
Live data does display the valve operation.....it does take one hell of a blip to get the valve to go on the later 2.5's

Ahh.... so it may all be well, then?!

Next step - Drive it with a T2 plugged in?

Under what driving conditions should it open?