DIY_EFI Digest Friday, August 6 1999 Volume 04 : Number 453 In this issue: tbi to tpi Re: Electronic transmission controller? Re: DIY_EFI Digest V4 #451 Acceleration enrichment Re: DIY_EFI Digest V4 #450 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Fri, 6 Aug 1999 05:49:16 EDT From: EFISYSTEMS@xxx.com Subject: tbi to tpi Hi, I could be completely wrong with this, but I have done swaps like this in the past with no problems.....Ludis,Terry and others might have some more insight on this.......yes the signal from the vss is diff...but all the 730 cares is: has tps lowered and has vss lowered....therefore decel enleanment...you will have to play with some of the mph and tps stuff in your 730 chip but you can make it work......pulses per mile is the area that needs to be changed for correct lockup of the torque convertor....,,,,,,,if I am missing something guys I would love the feedback. hth's - -Carl Summers In a message dated 8/4/99 12:18:32 PM Pacific Daylight Time, DIY_EFI-Digest-Owner@xxx.edu writes: << Date: Tue, 03 Aug 1999 14:12:45 PDT From: "David Sagers" Subject: TBI to Port Injection I ran into a brick wall with my DIY EFI project this morning. I'm converting a '92 Suburban TBI to a '90 TPI MAP system. I have about all the parts including the TPI system, brackets, cables, etc... Called this morning to buy the wiring harness and the tech at Painless Wiring said that I was headed for a big problem. The speed sensor in the Sub runs the speedometer and something to do with the brakes. He said the problem is that the TPI ECM uses a different speed sensor than the TBI uses. And they are vastly different in the signals they produce, are not interchangeable, nor can you run a dual sensor system. I remember seeing in a Jegs catalogue that Edelbrock sells a multi-port system that uses the the TBI computer but requires Edelbrock's chip to make this work. I called Edelbrock and they do not sell this chip separately, only with the full EFI set up. The Edelbrock system was a possibility until; 1) the tech said that his system is not big enough to feed the 400 SBC I have ready to go in the truck. The injectors are only 19 lbs/hr; 2)and the tech said that the cam I using would require a custom chip anyway. I may have given him the wrong specs on the cam because I bought a mild towing cam for the Suburban; 3) I've already paid for all the TPI stuff and really like the long runners on the TPI, not sure I can really afford to shell out another $1000 for Edelbrock system. Some where in the box with the TPI stuff is a harness adapter that is suppose to convert the TBI injector harness to an eight injector harness for the TPI. But the big question. Does anyone know of a chip maker that makes a chip that will allow my TBI computer run a TPI system? >> ------------------------------ Date: Fri, 06 Aug 1999 06:34:47 -0400 From: Shannen Durphey Subject: Re: Electronic transmission controller? > > Date: Thu, 5 Aug 1999 16:03:52 -0700 (MST) > From: d houlton x0710 > Subject: Electronic transmission controller? > > Anybody ever worked on a controller for the GM electronic trannies? > Specifically the 4L60-E? What about a commercial one? Is there one > available that's stand-alone and adjustable? > > Were the OEM controllers stand-alone or part of the EFI computer? I don't know about the 4L60E, but the diesels with mechanical injection and 4L80E had a trans controller. There's a company that reprograms them to use with NA diesels, I can't remember their name. Any car or gas engine truck with the 4L60E should have EFI, and trans control is in the same computer as EFI. Shannen > > Is there an aftermarket efi controller (Haltech, TEC, Wolf, etc?) that > can also control this tranny? > > thanks > - --Dan > houlster@xxx.com > ------------------------------ Date: Fri, 6 Aug 1999 07:13:53 -0700 (PDT) From: pjb@xxx.com (Pete Boggini) Subject: Re: DIY_EFI Digest V4 #451 John Dammeyer asked: > Subject: External Injection Fuel Pump > > Hi, > > Does anyone have a source for externally mounted fuel pumps for > injection systems. Can't put the pump in the tank. We need only about > 40PSI. > Yes. Try the E2000 from Airtex. Its the stock replacement pump for Ford F-series trucks, XR4Tii's, etc. Its an 80-90PSI rating with about 38GPH. Try 1-800-4-airtex for more info. The pump ranges in price from about $75.00 to about $125.00. peterb ------------------------------ Date: Sat, 07 Aug 1999 03:03:04 +1000 From: Phil Lamovie Subject: Acceleration enrichment Re: DIY_EFI Digest V4 #450 Hi All, For a simple solution to acc enrichment start by creating a FIFO stack of say ten counts. Read TPS every 10 ms. Algorithm should respond in a linear fashion to the diff b/w first and last. Say 100% of additional fuel for 200% change in A/D value. A single integer value of X ms will give you an adjustable ramp rate. This is a simple feed forward system The harder part is to arrange a proportional decay vs rate of change of rpm If the engine rpm changes quickly you should decay the additional ms proportionally if the rate of change is slow then the enrichment should be adjusted to suit. Of course for an engine that has a very poor chance of acc quickly relative to say a blipped throttle during a down change this is really of little import. On the matter of duty cycle it's more to do with lousy linearity of an injector at either end of the scale 0-2 ms is considers to be unusable due to lack of repeatability. With 0.5 - 1.1 ms just to open this gives rise to variations cycle to cycle of more than 8 %. Makes it hard to pass US pollution laws. At the other end of the scale the rate of collapse of the magnetic field and the fuel pressure together with pintle bounce mean that 90 % duty cycle could in fact mean that the injector never closes. F1 engine at 16,000 rpm has 3.75 ms per rev losing 0.5 to open and 0.65 to close would give a max. of 2.6 ms. Thus one injection per 2 revs. And you were worried about timing the injection to coincide with valve train events. Be wary of any O2 sensor voltage vs A/F ratio inferences. If you don't correct for temp there is a drift of 1.5 A/F over 400 deg c. And that's for the expensive BROAD BAND device. A single wire sensor can't be trusted at all. For any peace of mind use a 4 Gas analyser and EGT. Then refer to EGT and infer A/F from that. Be sure to refer to the properties of steel/wire/bailing in the BLUE BOOK to aid with exhaust mounting redesign For the key to all things in auto tech The Bosch Automotive Handbook SAE order no is BOSCH4 (4th Edition) It's blue !! ISBN 1-56091-918-3 best $35.00 you will ever spend. DISCLAIMER .......I am a hopeless addict of the SAE book store and would buy everything if I could. Regards Phil Lamovie injec@xxx.au cogito ergo zoom ------------------------------ End of DIY_EFI Digest V4 #453 ***************************** 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".