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M20 Dbilas issues
Posted: Fri Nov 02, 2007 6:56 am
by eb224
Hi All,
I have a 88' 325i which I have installed a Dbilas multi throttle intake manifold onto and have got the engine running. The issue I am currently faced with is that it idle's fine but when the rev's rise to more than 1750rpm the revs drop down to 1000rpm and then rises back up to 1750 again before dropping again and again.
Does anyone have any idea's??? I have checked the TPS switch and that is fine, the AFM is connected and working as far as I can tell.
Any help would be great.
Thanks
Leigh
Re: M20 Dbilas issues
Posted: Fri Nov 02, 2007 8:17 am
by Turbo-Brown
I'd say the fueling is out, you need to get hooked up to a WBO2 kit and find out exactly where the fueling's at.
I had exactly the same symptoms as you describe when I got my ITBs etc running.
Posted: Fri Nov 02, 2007 8:29 am
by eb224
Thanks Turbo-Brown I will look into that, though it means trailering the car to a workshop. Due to the car having a M52 2.8l crank and the dbilas I have E36 3.0l M3 injectors in it, which were fine before the dbilas upgrade, so it shouldn't be an issue with how much fuel though maybe I need a bigger regulator than the 3 bar that I currently have.
Re:
Posted: Fri Nov 02, 2007 8:39 am
by Turbo-Brown
It's impossible to say without knowing what the AFRs have gone to now.
Making any adjustments without knowing is just piddling in the wind unfortunately
I even tried to "tune" mine with a narrow band O2 sensor,
that was a completely dead end!
Re:
Posted: Fri Nov 02, 2007 10:43 am
by eb224
Ok, thanks I will organise to get it to a workshop so they can check it out... thanks for the advice.
Cheers
Re:
Posted: Fri Nov 02, 2007 2:09 pm
by Turbo-Brown
Cool, let us know how you get on.
Re:
Posted: Sat Nov 03, 2007 7:30 am
by eb224
Just another quick question, currently I still have a AFM and the standard Motronic, which has been chipped to deal with the cam, injectors, exhaust changes that I have made. I would like to keep the car as standard as possible but should I be looking at going to a megasquirt or something like that??? Seems to be the way to make more power out of the engines on the forum.
Re:
Posted: Sat Nov 03, 2007 9:44 am
by Turbo-Brown
If it were me, I'd be thinking of going over to a mappable ECU which can control fueling and sparks.
Unless you can do some kind of live mapping on the chip you have at a rolling road, you'll never realise the full potential of your new setup.
It will be very interesting to see what the chip you have has done to the AFRs.
Re:
Posted: Sat Nov 03, 2007 10:12 am
by Demlotcrew
one word MAXX
Re:
Posted: Sat Nov 03, 2007 4:25 pm
by Turbo-Brown
Wha's a one o' them then?

Re:
Posted: Sat Nov 03, 2007 4:28 pm
by maxfield
Re:
Posted: Sat Nov 03, 2007 7:54 pm
by Andy335Touring
Demlotcrew wrote:one word MAXX
Another one.......Emerald

Re:
Posted: Sun Nov 04, 2007 8:21 am
by eb224
Just been playing around with it all this afternoon and I have found that if I disconnect the idle control valve the car runs without any issue.... will rev up to 3k and stay there without any issue...
Re:
Posted: Sun Nov 04, 2007 8:50 am
by Demlotcrew
have you got the ICV the right way round? It will only control flow of air one way.
Andrew
Re:
Posted: Sun Nov 04, 2007 11:07 am
by eb224
If you had of asked me that question before playing around I would have said yes. Now I am not so sure. I will check it all out tomorrow and see if that's the issue.
Thanks
Leigh
Re:
Posted: Mon Nov 12, 2007 4:36 am
by eb224
Hi All,
Thanks for your help, I did have the ICV the wrong way round but that wasn't the issue, the issue was that the TPS switch wasn't set 100% right, once I had reset it so it was right the engine just purrs.
Does anyone know if Dbilas are meant to supply a throttle cable for RHD cars, I have been in contact with them but I am awaiting an answer.
Thanks
Leigh
Re:
Posted: Mon Nov 12, 2007 6:24 am
by daimlerman
Would be interested to hear what this engine makes on a rolling road...
Re:
Posted: Mon Nov 12, 2007 9:10 am
by eb224
Damn Dbilas, they don't have a throttle cable for a RHD car.... not happy.

Re:
Posted: Mon Nov 12, 2007 5:04 pm
by daimlerman
Do you know what length you need? What fittings at each end? Speedograph Richfield in Nottingham(I think) make cables.Check the back pages of Practicle Classics for their details.
Re:
Posted: Mon Nov 19, 2007 8:52 pm
by --alpina--
Are there any pictures of your cars with the Dbilas setup ??? would be great to see as im very much seriously contemplating on buying this setup any time my self and!!!
cheers
j