Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X5 E53 (1999 - 2006)

X5 E53 (1999 - 2006)
The X5 SAV Forum

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 12-05-2012, 01:32 AM
Graham132white Graham132white is offline
Registered User
Location: Manchester UK
Join Date: Dec 2012
Posts: 41
Mein Auto: E53 4.4i X5
Help! Very technical problem!

Hi guys..

Ok, so I've got a 4.4 V8 E53 2001...LPG converted 80k

Im very mechanically minded but this problem is very hard to get my head round,, basically the car will not run right on petrol, it won't go over 3k revs and splutters and misfired badly although it will idle perfectly. If I unplug the MAF it runs like a race car v8 so I'm discounting bad coils etc, plugs are brand new.
I've got no fault codes either!!

It runs perfect on LPG while driving and has perfect response on the throttle but idle on LPG is fine until you touch the throttle a little which makes it bounce up and down to about 2k revs down to 0 and sometimes cuts out.
The BRC LPG installer says he has fuelled the LPG correctly to run right, which it does.
On petrol the short term trims go up high only when you rev it and the longs are hovering about +12.

All this would tell me there is a vac leak or bad maf but that wouldn't explain it's smooth running on LPG, or would it? I've sprayed all over the manifold looking for leaks and gaskets were done not long ago.

I just ain't got a clue rom here.... Any help would be greatly appreciated!
Reply With Quote

See More Related BMW Stories

Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X5 E53 (1999 - 2006)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT -7. The time now is 01:07 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
© 2001-2015 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms