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View Full Version : i figured out my wot lean problem on my 325



winfred
07-06-2004, 11:40 PM
the wide open throttle part of my tps must of died in the last couple weeks, my battery died last week in the 325 and reset the computer and it takes a couple days to adjust to my 19# injectors and 535 air flow meter/overbore throttle body and headers, i finally got time to check it out today and follow up on a hunch, it's much happyer now, i think that's the 1st electrical failure i've had on that car in almost 70k miles, i've replaced stuff for preventive mantance and upgrades

winfred
07-26-2004, 09:29 AM
i just found the last lean problem, i just had to lean it out the richen it up, the afm was going to full open too early so i tightened the spring 2 notches as a experament and now it runs like a bat outta hell, woohoo

BCOOK2
08-10-2004, 09:55 PM
If You Don't Mind Me Asking, What Were The Symptoms? Did The Car Still Run And Drive?

winfred
08-10-2004, 11:11 PM
it ran fine during normal driving, it just didn't always go rich at full throttle, you could feel it when it would swing from lean to rich at wot, id get a big surge of power around 4k but when id floor it at lower rpm's it didn't fatten up like it should, i have a af ratio gauge so i knew what it was doing, it just took several months to get time to figure it out because i've been so overloaded with work at the shop (nothing but misery jobs too, i hate "car in a box" ), i can floor it at 2k and the mixture will swing to the rich end of stoich and hold their till 6500, i flogged the **** out of it all last week and it ran like a scalded dog and still got 23+ mpg
http://members.cox.net/wdixon27/gauges

mrbmw1
08-11-2004, 09:54 AM
how much work is it to change over the amf to the 535 & what year 535 and do the injectors plug right in or do the need special work
I know what you mean all last month I had head ache jobs could'nt work on either except for needed water pump & timing belt no upgrade stuff. If not to much of a problem drop me a line w/ the procedure for the change over at mr bmw1@hotmail.com
thanks

BCOOK2
08-11-2004, 09:13 PM
Air/fuel Ratio Gauge Is Next On The List. I'm Running At 25.2 Mpg In Town Which Leads Me To Believe My Dead Spot In The Low Rpms Is A Lean Problem. I Have An Extra Tps I'll Try This Weekend. Thanks!

BCOOK2
08-11-2004, 09:24 PM
I Didn't Have Instructions, But I'll Give As Much Self Learned Advice As Possible. You'll Need An Afm Out Of An E28 535i/is. There Is A Plastic Cover On Top That Can Be Pryed Off With A Little Patience. You Have To Switch The Resister Boards From Your Stock Afm To The 535 Afm. (including The Terminal So You Can Plug It In To Your Factory Computer). The Flap That Opens/closes Is Controlled By A Spring Mechanism That Needs To Be Loosened. (i Had To Play With It Just A Bit To Get It Idling As Good As Possible. Also Remember The Computer Will Have A Little Trouble With The New Component At First Until It Learns What's Happening.) I Used My Factory Intake Hose And Warmed It With A Hairdryer. Then I Stretched It Over The Larger Afm. I Stretched My Old Cone Filter Over The Front The Same Way. Then You'll Need To Make A Couple Of Small Brackets To Bolt The Afm To Stock Location. The Install Turns Out Looking Not Far From Stock. Hope This Helps! You'll Be Surprised How Smooth It Goes.

winfred
08-11-2004, 09:34 PM
the injectors drop right in, the ones i got for both my bimmers are the disc type from a 4.6, they did screw up the calabration on the obc of the e30 for range and mpg, it reads about 6 high because of the shorter pulse width. on the afm i took the electronics out of a m20 afm and put it in a 535 e28/34 (it doesn't really matter you just need a large bosch afm, several porsches have the exact housing/flapper and usually have a neat aluiminum airhorn, i am sure it lives under the hoods of many other cars (cheep in a salvage yard) you need to figure out the proper spring tension which is mostly trial and error, my af gauge helped and at 60 couple bucks looks neat in the ashtray slot teamed with a matching volt meter (ill be adding oil temp and pressure to the a piller)

ps the screws want to snap off real bad on the board in the afm


how much work is it to change over the amf to the 535 & what year 535 and do the injectors plug right in or do the need special work
I know what you mean all last month I had head ache jobs could'nt work on either except for needed water pump & timing belt no upgrade stuff. If not to much of a problem drop me a line w/ the procedure for the change over at mr bmw1@hotmail.com
thanks

winfred
08-11-2004, 09:52 PM
this is the only pic i have on my computer of it, i modded the stock box to accept the 535 afm i allready had a k&n in it and i also modded a porsch afm airhorn to go inside, to get the airboot i chopped a m50 boot and fit it over the end of the m20 boot and sealed it so i didn't need to stretch anything, you can see the duct tape i used to hold the lid on till i finished tweeking it, so it looks almost totally stock (till the tech inspector spots the headers)
http://members.cox.net/kitlou/m20motor


The Install Turns Out Looking Not Far From Stock

BCOOK2
08-11-2004, 10:38 PM
Very Nice! The Stock Airbox Is The Only Way To Go. My Car Obviously Had A Juvenile Owner And Was Appropriately Equipped With A "hot Air Intake".(unshielded Cone) Haven't Gotten Around To Building A Box For It, But Will Soon.