DIY_EFI Digest Tuesday, January 18 2000 Volume 05 : Number 028 In this issue: lambda sensors Re: EGR and knock,was DIY_EFI Digest V5 #25 RE: Vortec 4.3 & 747 RE: New to the List. Re: DIY_EFI Digest V5 #27 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 18 Jan 2000 02:35:50 -0800 From: "Lowell Foo" Subject: lambda sensors .85 LA would be 12.5:1 and .89 LA would be 13:1. With a heated lambda sensor I don't think placement matters at all. I tried running 2 Bosch LSM-11 sensors on my Talon, 1 in the stock location just after the turbo and one in the tailpipe. The stock sensor is read by the cars Motec ECU and the tailpipe sensor by a Fueltronics handheld. The readings agreed within 1% on a sensor rated for 1.5% accuracy. Also as far as I know you cannot just read voltage off a lambda sensor because of EGT compensation but I've never tried it. ------------------------------ Date: Tue, 18 Jan 2000 09:41:05 -0600 From: "Robert W. Hughes" Subject: Re: EGR and knock,was DIY_EFI Digest V5 #25 > > The knock is caused by a lack of exhaust flow back to > > the intake which cools the fresh charge. > > How does the hot exhaust gas cool the fresh charge.... Or have I got this > wrong and you mean that the exhaust gas isn't heating the cool intake > charge and the cold intake charge is causing the detonation???? Actually, the exhaust gases dilute the mixture and make the combustion temperatures lower. To compensate for the reduced speed of combustion, extra timing advance is added by the ecm. If the ecm adds the timing and the egr is not functioning, (this typically occurs at highway cruise speeds) you can get continuous pinging which goes away when you step on the gas. - -- Robert W. Hughes (Bob) BackYard Engineering 29:40.237N, 95:28.726W Houston, Texas rwhughe@xxx.net ------------------------------ Date: Tue, 18 Jan 2000 10:18:15 -0800 From: "Mendell, Richard" Subject: RE: Vortec 4.3 & 747 Do you mean a 700R4? The 727 is a Mopar tranny and would require an adapter (available from Advance Adapters, if that's really what you need). If you have the 700R4, it's a pretty clean swap. The basic hook up is identical and a donor vehicle should provide all the necessary parts. Remember, even the HO 4.3 Vortec is still TBI, as I recall that most of the '86 installations were as well, and the 700R4 soldiered on with even the HO 4.3 until '93 or '94. If you are dropping in the HO motor though, the tranny will need upgrading to the late 700R4 standards, as the early ones (like '86) were a bit weak. Kits are available to do this. Cheers, Richard P. Mendell '91 GW ("The Yak"...150K...TBI Pending) Long Beach, CA "I never could get the hang of Thursdays." - A. Dent > ---------- > From: clive@xxx.org] > Sent: Sunday, 16 January, 2000 12:39 pm > To: diy_efi@xxx.edu > Subject: Vortec 4.3 & 747 > > > > anyone ever swapped a 4.3 late model ~@00hp Vortec into a 86 Vintage > vehicle with a 727 and 4.3 original > > what cals di you use in the 747 > > Thanks > Clive > ------------------------------ Date: Tue, 18 Jan 2000 10:23:53 -0800 From: "Mendell, Richard" Subject: RE: New to the List. Can't help you on the Drag car or computer, but EFi for the Rover 8 is easy. Just remember that from the mid-Eighties on, that all Land Rovers featured a EFI on the Rover/Buick 8. Cheers! Richard P. Mendell '91 GW ("The Yak"...150K...EFI Pending) Long Beach, CA "I never could get the hang of Thursdays." - A. Dent > ---------- > From: William Brennan[SMTP:STDBoy@xxx.net] > Sent: Sunday, 16 January, 2000 2:45 pm > To: DIY_EFI@xxx.edu > Subject: New to the List. > > Hello all, > I am new to the list, but like everyone I want to build a EFI for my > car. I have read through the archives and I just have a few questions. > I am also new to the Microcontroller world (Haven't bought anything yet, > just a lot of reading) and the likes, so please bear with me. It seems > that the MicroChips are the easiest to start learning on. Am I correct > on this? I would like to update the program via my laptop, so which > chip series might be the best? What books or software hardware etc etc > would I need. I know a lot about cars, just not the electronic stuff > just yet, but I am willing to learn. Any help would be apreciated. And > if it matters, I am going to put the EFI on a 1971 Chevelle w/ a 498" > Nitrous breathing rat motor for Drag Racing only, and maybe put the EFI > on my TR7 when I drop the 5.2l rover v8 into it...Thanks!! > > Lee > ------------------------------ Date: Tue, 18 Jan 2000 11:57:04 -0800 From: "Scott Croughwell" Subject: Re: DIY_EFI Digest V5 #27 > How does the hot exhaust gas cool the fresh charge.... Or have I got this > wrong and you mean that the exhaust gas isn't heating the cool intake > charge and the cold intake charge is causing the detonation???? Believe it or not... the gasses coming from the EGR have had enough time to cool enough so that the portion of exhaust temp re-entering the intake port is cooler than the intake manifold. (Thus, EGR valve only opens when the engine is at "operating temperature".) But if engine knock is only apparent at something other than high engine loads and/or speeds... I'd be willing to bet dimes to dollars it's due to the EGR being disconnected or inoperable. Scott ------------------------------ End of DIY_EFI Digest V5 #28 **************************** 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".