| BMW fuel additive results in decreased mileage |
| longinot | I recently added an OEM fuel additive to my 86 735i. As a result my MPG has gone to around 11 MPG. How can I recover from the results of this product, short of changing injectors. In the last two months I have in an effort to increase the MPG, changed rotor and cap and air filter. I have not replaced plugs or wires. I noticed that Jens had mentioned in a post about a potentiometer setting on the Motronic and would like to know more about this subject. If anyone could expound on this subject I would certainly appreciate any input. Thank-you in advance.
Tommy Longino |
CLICK HERE TO VIEW TOPIC IN THE FORUM
| Jens | 1.) Wait tuill you fill up again to normalize the system.
2.) Remove your AFM clean it ver good.
3.) Remove plastiv cover from AFM clean contacts with
white erasor, then reseal the plastic w.cylocone.
4.) Make sure your vacuum system is A OK espacally the
check valve bewteein intake and pump.
This is where i would start.
Sincerely Jens |
| scottie | You may have been running lean before due to a clogged injector and someone adjusted your mixture to compensate. Now that your system is cleared up, you are running lean. This is just a guess!
Scottie Sharpe
Sysop
84 745i
85 535i |
| longinot |
Thank-you. I cleaned the foil trace on the AFM with a white eraser and it now seems to run smoother. The vacumn pump runs, although it sure seems slugish and my need replacing. I would like to find a source other than the dealer for a vacumn pump as $290 seems steep. I really won't know if my situation has improved until I fill up again and hey thanks for setting up a space for us 735i folks to post on the 745i board.
|
| Jens | If your pump runs all the time,
it means it may be good,
pinch the black line on driverside
of pump, see if it shuts off, if so then
this means pump is good but u have a vacuum
leak somewhere, now check the check valve
first which comes from the intake and T'S of
to the pump.
Sincerely Jens |
| scottie | I would disconnect your vacuum pump before you burn it up. It is not required unless you regularly go up long steep hills anyway.
Scottie Sharpe
San Jose CA
Discussion Board SYSOP
84 745i
85 535i |