Vanagon EuroVan
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Date:         Sun, 30 Dec 2001 21:40:22 -1000
Reply-To:     Ed Sato <edsato@JUNO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Ed Sato <edsato@JUNO.COM>
Subject:      Re: Understanding AFC fuel injection--question
Comments: To: VGONMAN@MSN.COM
Content-Type: text/plain; charset=us-ascii

. What I do not get is the process when it is starting cold.....air flows thru the AFM, and if the motor is cold enough, the auxillary air regulator is open, and air is diverted to the intake manifold, thus bypassing the throttle body. This book says that this enables the motor to act the same cold as it does hot, for the control unit adds additional fuel to the injectors when it senses the engine is cold. Now, there is no sensor, or anything on the throttle body, so how does this auxillary air regulator do anything?

Adam I am not an expert on this subject. But from what I see....on cold start most engines have a step throttle stop on the carburetor to increase the idle speed for warm up purposes. The vanagon does not. So it instead has sensors that distribute extra air and gas that bypasses the throttle plate so that higher idle speed can be obtained for warm up. I notice that it is not the same as other cars in that you do not need to step on the pedal to bring the idle back to normal. But then again other problems may occur when this type of system is not operating correctly. Importance here make sure all sensors are good. I too have problems with bad fuel mileage. So far replaced plugs, filters, O2, T II with no change. I used to have 19 -20 mpg. Went down to 18 then 16 until recently 14mpg. Started replacing above when it hit 14. The last thing I replaced was my fuel pressure regulator. It did not seem to be bad but I figured since my van has 200,000 miles it will go bad anyway. Plus the fact that Ken had that great price for it (Thank you Ken Wilfy!). I also did not have a fuel pressure gauge. What I did notice after changing it. First after removing it I tried to see if there was any difference in back pressure. No gauges used the old fashioned pressure by mouth. The new one held pressure, the old one also held pressure but detected some leakage. It was here that I had second thoughts about this being the cure to my problem. After changing it I feel that this may have been the problem all along. Van drives alot better below 3000 rpms. I haven't checked my mpg yet but will report back if anyone is interested. Another thing that I did notice which may not have any bearing to the changing the FPR is that I used to have the same hot start problems that most of the lists were mentioning. It just dissappeared which kinda makes sense to me now but being that everyone has their own opinions. I leave it up to your own imaginations. Hope this helps you Adam. If not well Have a Happy New Year anyway! Aloha, Ed

P.S. To all of you other Vanagoners out there. I have learned alot about the fuel injection system through your bickering , rantings and ravings and of yeah down to earth helpfullness. I would like to thank you all too and wish you all a Happy New Year!


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