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Model specific boards => Golf mk4 => Topic started by: number1bassman on 16 March 2011, 15:56

Title: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 15:56
Quick question people, what's the difference between the inlet manifolds on AUM and AGU engines?

My car used to have an AUM but now has an AGU and I want to know if they have been swapped and if so, what would happen if they had fitted the AUM inlet manifold on the AGU engine?

Cheers for your help!  :smiley:
Title: Re: AUM / AGU Inlet Manifold
Post by: Phil_M on 16 March 2011, 18:46
If its got a bracket on the front for the throttle cable then its an AGU.
(http://img.photobucket.com/albums/v218/pipmann30/DSCN8284.jpg)
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 16 March 2011, 18:49
The AGU inlet manifold is larger port than the AUM. Also has a bracket for throttle cable and on one of the ports the bolt hole for the bracket that the engine cover screws into is in a different position.
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 19:23
Phil, that picture is great!  Thanks for that!  :smiley:

Right, so I have got an AGU inlet manifold on my engine.  Next up, what's the difference between the injectors and will AUM injectors fit into the AGU manifold and how do I tell which ones I've got? 

Can you interchange the injectors between the manifolds?

And, would it cause any issues having an AGU manifold and injectors wired up to AUM ECU?

Just so you know, I'm trying to work out why my car doesn't go properly and I'm running out of ideas!
Title: Re: AUM / AGU Inlet Manifold
Post by: Wazzzer on 16 March 2011, 19:28
AGU and AUM injectors are not easily interechangable as they are physically different sizes. Also they have different flow rates so unless your car has been mapped to the AGU injectors I doubt it will run right...
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 19:40
AHA! Wazzzer, you little beauty!    :drool:

So, if my AUM engine had been changed to an AGU engine with inlet manifold and injectors, unless someone remapped it for the AGU injectors, it'll run funny and not as it should?

This could explain why my car isn't as quick as it should be?  The AUM was replaced with an AGU, including manifold and injectors, but they kept the original ECU and mapping and that's why it doesn't run right!!!

Bugger, now that means I need a re-map?  :undecided: :cry:
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 16 March 2011, 19:51
that sounds like the problem mate
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 20:02
Hulmie, Thanks for confirming it for me!  I had an idea there was something wrong with the mapping, always felt like the fuelling was wrong.

Right, now, anyone know anyone near Northampton where I can can get it remapped for the injectors?  I don't want to make it any more powerful, I just the bloody thing to run as it should!

Anyone help me?
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 20:49
Okay, how about if I get an AGU ECU will it fit?  I don't mind re-pinning the ECU, would it work okay?  I would lose the boost pressure sensor and the SAI and the downstream Lambda wouldn't I?  Might be a better option.

I could swap my ECU with someone with an AGU if it will fit okay?   :cool:
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 16 March 2011, 21:06
if your still running the AUM ecu and loom then i suspect that you will still be running a map sensor. So you wouldnt be able to use a AGU ECU as the agu's dont come with a map sensor. Another thing is you could still be running aum injectors in a AGU inlet as i believe you can use them by changing the injector seats in a AGU manifold for the ones used on a AUM and then just space the fuel rail abit.

The setup you have may be ok and the only way to find out is for someone to do some diagnostics on it and do some data logging. Personally i would give R-Tech a call and get them to sort it for you. As they would probs put it on the rolling road and do some live logging and sort the map out for ya.

If you dont want to travel then local places to you are Jabbasport in peterborough and Backdraft motorsport in Milton Keynes. Personally i would use R-Tech
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 21:15
Hi Hulmie,

Cheers for your quick response.

I am running a boost pressure sensor in the intercooler.  I don't have a problem re-pinning an ECU to remove it though!

I don't suppose anyone has any pictures of the injectors in situ?  I can't tell if the ones I have are AUM or AGU, is there a quick way?

But I think a trip to R-Tech is a good idea.  Do you have any idea how much they might charge me just to sort it out?  I don't want it re-mapped to go faster, standard would be fine!
Title: Re: AUM / AGU Inlet Manifold
Post by: Wazzzer on 16 March 2011, 21:58
AGU on the right, AUM on the left.

(http://i49.photobucket.com/albums/f291/bens_cab/d292e00e.jpg)
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 16 March 2011, 22:00
im not sure if you would be able to see the part number on the side of the injector. if you could get this then im sure someone could check etka and tell you which ones you have.

Not sure what they would charge mate, best to call them and speak with them about it.
Title: Re: AUM / AGU Inlet Manifold
Post by: tech1889 on 16 March 2011, 22:05
typical rusty agu on the right  :laugh:
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 16 March 2011, 22:08
Thanks guys, they look really different.

I think I could tell which ones I've got just by looking under the bonnet thanks to that picture.

I've just sent an enquiry on the R-Tech website and will probably give them a call tomorrow and beg for help.  :cry:

Thanks again for your help and I'll keep you posted.  :smiley:

Would I be right in thinking the AGU injectors flow more than the AUM or vice-versus? They're much bigger, but then, size isn't everything!  :wink:
Title: Re: AUM / AGU Inlet Manifold
Post by: tech1889 on 16 March 2011, 22:18
bigger doesnt always mean better  :grin:

sorry had to be said
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 09:06
Good one Tech, you took the words right out of my mouth!
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 13:01
Okay, so I spoke to Jim at R-Tech, and he reckons the best thing to do is get the AUM injectors and fit them in somehow.  He said it'll be cheaper than doing a diagnostic on it and re-mapping it to cater for the injectors.

So, does anyone have any AUM injectors lying around they no longer require?  :wink:

Standard if possible as I'm not trying to make a flyer, just a nice reliable (fairly) MKIV Golf.

I've just taken a look and reckon I could somehow get them to fit!  Or, has anyone done this already and got any tips?

Cheers guys, hopefully, I'll have a decent car someday that goes as it should!
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 17 March 2011, 13:18
You would need to get new injector seats from VW aswell and also space the manifold some how.
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 13:26
Cheers Hulmie, after rummaging around on uk-mkiv and clubgti,they said the injectors fit in the seats but the rail is obviously too high so the posts need chopping down.

I am going to have a go at this as I have no money left to pay for a re-map.  Or, would an AUM fuel rail fit straight on?

I am quite prepared to pass my injectors on or swap them once this is sorted, so if anyone has some AUM injectors and a rail they don't want, I'll fit them to mine and send you the old ones back?

Will ask Jordy if he's got any lying around too!

Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 14:32
Okay, a random dodgy strange and weird question.  What if I were to fit a fuel pressure regulator that allowed a higher pressure?  If the AGU injectors inject less than AUM injectors, if I boosted the fuel pressure, would that compensate for the lesser injector flow?


Just a thought!  :laugh:
Title: Re: AUM / AGU Inlet Manifold
Post by: rockmonkey69 on 17 March 2011, 15:56
Well standard fuel pressure regulator is 3 bar and so too is the fuel pump. It might give a bit more flow but not alot. Most people who go for turbo upgrade on AGU run genesis injectors. Whereas those running AUM have a bit more choice at the 300 bhp range  :cool:
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 16:37
Cheers rockmonkey, I don't want to upgrade them, I just want my car running as standard really!  Either I get a set of AUM injectors and chuck them in, or I get an ECU for an AGU and re-pin the connector, which I don't mind doing!

I was just wondering if that'd work!
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 17 March 2011, 17:12
even upping the fpr wouldnt make a difference at the car will be mapped to flow 'x' amount at 3 bar.
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 17:15
Cheers Hulmie,

So, I either:

Get AUM injectors.

Get it re-mapped.

Or get an AGU ECU and re-pin it.

Is this about right?

And if so, can anyone help with any of the above?  Pretty please???
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 17:22
Okay, the AGU ECU won't plug in.  So it's re-map or injectors.

Anyone?
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 17 March 2011, 17:30
if your not fussed about more power then cheapest option is injectors. Best option would be find someone breaking a AUM. But also make sure you can get them to fit ok without leakage
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 17 March 2011, 19:23
Cheers Hulmie,

Does anyone have any AUM injectors please? Pretty please??   :rolleyes:
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 17 March 2011, 21:53
just checking, but you have done a scan for fault codes? You done any data logging?
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 18 March 2011, 09:07
Hi Hulmie,

I haven't done any data recording, but I have a 1552 and access to a 5051 and there are no fault codes since I fitted my Lambda probes as I was having a downstream resistance code.
Title: Re: AUM / AGU Inlet Manifold
Post by: Hulmie on 18 March 2011, 11:52
main thing is you dont have any codes coming up, that helps eliminate things. Last thing you want to do is change the injectors over and still have problems.
Title: Re: AUM / AGU Inlet Manifold
Post by: number1bassman on 18 March 2011, 11:59
This is true!  It's taken me a while but I am codeless now!  Which is good, but the bloody car is still running rubbish!

But, at least I know what's causing it, or hopefully.  :tongue: