DIY_EFI Digest Sunday, 15 June 1997 Volume 02 : Number 202 In this issue: Re: Diy_Efi for '49-53 Ford Flathead Re: O2 sensor meter Bosch Platinum plugs, Slick-50, Mobil 1, and Armor-All !! Re: O2 sensor meter See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: JColl62271@xxx.com Date: Sat, 14 Jun 1997 17:55:02 -0400 (EDT) Subject: Re: Diy_Efi for '49-53 Ford Flathead If you find a reasonably good solution, either homebuilt or adaptable, which doesn't cost a small fortune, include me in. I want to put a TBI on two cars; a 66 Mustang with a 250 six and a 53 Plymouth with a flathead six. Great engines, just need a little help to make them more driveable. Jack ------------------------------ From: Kevin Rutledge Date: Sat, 14 Jun 1997 16:47:03 -0700 Subject: Re: O2 sensor meter At 09:08 AM 6/14/97 +0200, you wrote: >I have made the EGO sensor meter for my car, but I have found that the >voltage across LAMBDA sensor is not stable. >I mean, when the engine is running at its minimum (about 800 RPM), >the voltage go up and down around 0.5 V with a frequency about 3-5 Hz. >Why? >How can I connect your EGO sensor meter in order to have a stable value? > O2 sensor voltage is supposed to oscillate at idle. There is no way to change this behavior. If you mixture is set wrong (too rich, too lean) then the voltage will stick to one end of the range. Kevin Rutledge Saab & Volvo technician ------------------------------ From: Daniel Burk Date: Sat, 14 Jun 1997 22:26:25 -0700 Subject: Bosch Platinum plugs, Slick-50, Mobil 1, and Armor-All !! I thought I would interject a little study that I performed on the standard AC plug, the Bosch Platinum, and the Rapidfire plug by AC. I went from a standard AC to the Bosch in 1993 at 65,000 miles, and picked up 2 MPG; I also replaced teh timing chain at the same time, as well as the plug wires. Take it for what it's worth. I replaced the Bosch plugs at 90,000 miles in 1995 with AC Rapidfires. I saw no performance imrovement, even considering the Bosch plugs had 25,000 miles. The Bosch still look good and I could re-install them. At 115,000 miles, I noticed that the Rapidfire plugs had the splines that they advertise burned off them. I use a Accel supercoil and a Crane Hi-6 ignition module. I regapped them and reinstalled them. At 124,600 miles, the car has begun to miss. The distributor cap's brush to rotor interface has burned out it's electrode (Totally turned to slag!). The Rapidfire plugs have burned off their electrodes as well. I've disconnected the Hi-6 CDI unit. I plan on buying a new set of the Bosch Platinums, as well as a new coil and spiral core wires. - ------------------------------ Regarding Split Fire plugs and Slick 50: I got a tour of Roush Industries in 1995. While in the Dyno building, where 15 dyno cells were all running at wide-open throttle, I asked the Roush representative if they had ever tested Slick 50 and/or Split-fire spark plugs. The rep said yes, they had extensively tested both products. Roush industries said that they saw no measureable increase in performance from either product. I underline the word measureable. The tests (I surmise) pit synthetic motor oil against Slick 50, and NEW plugs against NEW splitfires. When I asked which products have they seen positive results from as far as performance, they said look at Bosch Platinums and a fully synthetic motor oil like Mobil 1. I felt good, because I use both. Probably always will. I even have Mobil 1 in my lawn mower. One thing I swear by when it comes to performance, is that pure subjective feeling that my car runs better when it's washed and the tire's sidewalls are armour-all'ed! Cheers, Daniel Burk ------------------------------ From: Orin Eman Date: Sat, 14 Jun 1997 21:38:04 -0700 (PDT) Subject: Re: O2 sensor meter > At 09:08 AM 6/14/97 +0200, you wrote: > >I have made the EGO sensor meter for my car, but I have found that the > >voltage across LAMBDA sensor is not stable. > >I mean, when the engine is running at its minimum (about 800 RPM), > >the voltage go up and down around 0.5 V with a frequency about 3-5 Hz. > >Why? > >How can I connect your EGO sensor meter in order to have a stable value? > > > O2 sensor voltage is supposed to oscillate at idle. There is no way to > change this behavior. If you mixture is set wrong (too rich, too lean) > then the voltage will stick to one end of the range. If this is an LM3914 based meter, you can add some low-pass filtering at the input to smooth the oscillations. I have EGO -> 1Mohm -> 0.1uF to ground. The LM3914 input is taken from the 1Mohm/0.1uF connection. This smooths things a little (.1s Time constant). I'd try .47 to 1uF to really average it out. You do trade off response time though... the meter would be slower to respond and would miss transients. This doesn't seem to load the sensor any worse than going directly to the LM3914. DC input impedance is that of the 3914 plus 1Mohm... it drops to 1Mohm over a few 10s Hz (deliberately vague here). Orin. ------------------------------ End of DIY_EFI Digest V2 #202 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".