DIY_EFI Digest Thursday, 5 June 1997 Volume 02 : Number 191 In this issue: Re: O2 sensor mounting Re: did eveyone get the o2 sensor fooler? Re: O2 sensor mounting Re: Return Fuel Line Plumbing Re: Return Fuel Line Plumbing Re: O2 sensor mounting Re: efi problem See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Doug Robson Date: Thu, 05 Jun 1997 12:32:26 +1000 Subject: Re: O2 sensor mounting agreed fred i welded same to mine. I dont think 8 to 10 mm of protusion into the pipe is as bad as getting the mixture wrong in the first place and not knowing it. also o2 sensors ( especially wideband in leaded fuel only last 50 hours so you would take it out after dyno and use flush plug At 08:41 PM 6/4/97 -0500, you wrote: >What's a 'non fouler"? > >I just picked up an 18mm nut from the hardware store today for my new >downpipe. Can't get much simpler than that. > >Fred > >At 06:10 PM 6/4/97 -0500, you wrote: > >> The simplest method is to buy a "non-fouler" from the local parts store >>for $1.50 or so, drill out the bottom, and weld it in. Much cheaper >>than the special bungs. >> >> >> > > > ------------------------------ From: Doug Robson Date: Thu, 05 Jun 1997 12:51:06 +1000 Subject: Re: did eveyone get the o2 sensor fooler? i missed it can i have it please regards At 07:15 PM 6/4/97 -0700, you wrote: >Seth Allen wrote: >> >> Hey, did everyone get a copy of the o2 sensor fooler? Maybe it was a >> victim of the listserv failure, I mailed out the schematic as a .gif @ >> 15kb or so. >> >> Did anyone get it? >> >> If not, I'll repost it >> >> Seth > >Hi Seth, It looks great! Now I just have to figure out how to have the >ecm control it using a map of throttle position and rpm! Mark. > > ------------------------------ From: FreshMar@xxx.com Date: Wed, 4 Jun 1997 23:39:18 -0400 (EDT) Subject: Re: O2 sensor mounting I used a Bosch replacement O2 sensor, about $50 (a lot for me) new, that came with a flange to attach to the exhaust pipe. I just drilled the holes for the two mounting bolts and the sensor, cut out a suitable hi- temp gasket, and mounted the flange. The O2 sensor then screws in like it should. The flange I believe is st.steel, and is about 2-3 mm thick. It sould be no problem for someone compitent in welding to put one of these things on... Mario T. mailto:Freshmar@xxx.com-----'76 VW Camper FI A/T,,'79 Fiat X1/9 ------------------------------ From: FreshMar@xxx.com Date: Wed, 4 Jun 1997 23:39:46 -0400 (EDT) Subject: Re: Return Fuel Line Plumbing One thing I'd like to mention about fi return fuel lines- I had a wierd problem where my air- cooled VW bus would 'skip' in power on really hot days when I had less than a 1/4 tank full. Turned out there was a leak in my cooling tins, blowing hot air on the metal fuel rail. Presumably the fuel got warm, and not having a lot of cool gas in the tank to dillute it, warm enough to create vaperous bubbles that leaned out the mixture, made the engine run hotter...etc. Most of you obviously won't see that bad a problem, but fuel must be alowed to cool(dumped back into the main tank)- or never be alowed to get heated(insulated fuel lines). Just something to keep in mind if anyone is thinking about an auxillary tank. Mario T. mailto:Freshmar@xxx.com-----'76 VW Camper FI A/T,,'79 Fiat X1/9 ------------------------------ From: pantera@xxx.com (David Doddek) Date: Wed, 4 Jun 1997 22:57:53 -0500 (CDT) Subject: Re: Return Fuel Line Plumbing Aron wrote: >Is there any particular better place to plumb in a fuel return line >to a stock gas tank? >Above or below the average fuel line, top/bottom, submerged/not, etc. >-Aron Travis- >"always in a automotive frenzy" > > Return Line should always go to the BOTTOM of the tank and be submerged at all times. Why you ask, well I will tell you. If you do not return the fuel to the bottom of the fuel tank, then the high speed fuel splashing into the fuel in the tank will create little bubbles. These little bubbles will bet sucked into the pump and make the pump wear faster. They will procede on to the engine and get into the injectors where they will cause changing fuel mixtures and effect spray pattern and wear of injectors, and they will go throgh the regulator where they will make the regulator diaphram go crazy. A carb would not care since the float bowl is a damper for air and acts like a surg tank for the fuel so it was never a problem before. The sucking of air is also the reason for the baffles in the fuel tanks on the efi cars. When mine gets below 1/4 and I corner hard, the engine cuts out because of sucking air in the pickup. Just my few pennies. David Doddek pantera@xxx.com/~pantera 217-422-3722 69 EFI Fairlane, 89 T-bird SC, 74 Twin turbo NOS EFI Pantera #6825 If you are going to go fast, go real fast. ------------------------------ From: eric schumacher Date: Wed, 04 Jun 1997 21:00:17 -0700 Subject: Re: O2 sensor mounting I use Fiat rear axle nuts for O2 fittings. At 07:55 PM 6/4/97 +0000, you wrote: >O2 sensors are 18 X 1.5 mm thread and use a crush washer like some spark >plugs. You can buy a weld-on boss from Jeg's or Summit but it would have >to go on the exhaust pipe itself and not the cast iron manifold. > >Mike M. >ShadeTree Racing > >On Wed, 4 Jun 1997, Ron Madurski wrote: > >> : >> : >> :I have an exhaust manifold that does not have a tapped hole >> :for an O2 sensor but their is what looks to be like a spot >> :that is tapped out when this manifold was used on FI type >> :engines. >> : >> :Does anyone know what is involved in tapping an >> :O2 sensor hole? I think I read somewhere that you can't just drill >> :it and tap it with a normal tap because of sealing issues >> :between the sensor and the manifold once the assembly gets >> :up to temp. Has anyone done anything like this? >> : >> >> I got a boss for the O2 sensor from a speed shop and had it welded in to >> my existing header. >> >> :Any and all comments welcome! >> :TIA >> : >> :Greg Woods >> :gwoods@xxx.com >> : >> : >> >> >> -- >> Ron Madurski >> rmadursk@xxx.com >> > ------------------------------ From: Trevor Boicey Date: Thu, 05 Jun 1997 01:46:00 -0400 Subject: Re: efi problem Graham Hughes wrote: > Ford said and was confirmed by a second injection specialist that all > the voltage inputs to the computer were correct and so the computer was > replaced but to no avail. The fuel injected into the air depends on the injector duration and the fuel pressure. If you are getting way too much fuel, is there any chance a blockage is causing a really high fuel rail pressure? Also, most systems use a vacuum-attached fuel pressure regulator. This keeps fuel pressure at the correct ratio from manifold pressure to keep volume of flow the same. I can't imagine a mode of failure that would cause this, but positive pressure on the vacuum line will impede the operation of the regulator. - -- Trevor Boicey Ottawa, Canada tboicey@xxx.ca http://www.brit.ca/~tboicey/ ------------------------------ End of DIY_EFI Digest V2 #191 ***************************** 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".