DIY_EFI Digest Saturday, November 20 1999 Volume 04 : Number 652 In this issue: Even more retarded Re: DIY_EFI Digest V4 #651 Re: DIY_EFI Digest V4 #651 DIS See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sat, 20 Nov 1999 06:16:26 -0500 From: "Posea, David G, SITS" Subject: Even more retarded Thanks John!! I need to output crank signals instead of firing a coil, but the concept is the same. This is an add-on box, not a complete controller. But based on your input I think this will work: find TDC zero the timer on timer interrupt increment high byte of timer (16 bit resolution), if count = 36 make sure a tooth is missing. Zero timer at TDC on input interrupt store tooth number, timer value, and last two timer values. I would store all the tooth times, but would run out of ram. The last two should be plenty for up to 15 degrees of retard. main loop keeps track of output pulse count, and compares the timer to the stored timer for that tooth. If the delay is reached, send an output. If not, keep looping. I'll need an A/D converter for boost value (GM MAP sensor), and a lookup table for the delay based on rpm, but that should be easy. It may be even easier just to calculate the delay on the fly with a 20mhz processor. I know I can use the pre-scaler to slow down the timer, but should I do that, or increase the timer resolution to 24 or 32 bits? As always, thanks for the help!! David Posea ------------------------------ Date: Sat, 20 Nov 1999 06:58:46 -0800 From: Laura & Neil Subject: Re: DIY_EFI Digest V4 #651 > Date: Fri, 19 Nov 1999 18:40:07 -0500 > From: Darren Floen > Subject: Speed sensor > > Hi everyone.A while back i was asking questions about fuel injection for > a 4.3,being swapped into a Toyota.Well,i have now found a newer engine > to use.I picked up a 91 4.3 throttle body engine,from a Safari van. > > So now i need a wiring harness.I contacted Howell and Painless.Howell > says a speed sensor is not required for the engine to run smoothly.Matt > at Howell says that it will only affect the EGR,and not the IAC. > Painless says that the engine will always be stalling on deceleration. > > My question is this.How will the IAC motor reset its position if it > doesn't have a speed sensor input?It is my understanding that this > happens when the vehicle reaches 30 MPH. > > There is no smog testing where i live. > > So,do i need a speed sensor or not? > > Anyone know of any good websites dealing with 4.3 swaps and such? > > Thanks, > > Darren Floen > Thunderbay,Ontario > I assume this is going to be an engine and trans swap Darren The stock trans for the late 4.3 G.M's is the TH700 or derivatives. This uses a PCM controlled lock-up converter that is activated with the vehicle speed as one of the inputs. I'd say the speed sensor is very nessesary. Neil ------------------------------ Date: Sat, 20 Nov 1999 10:27:02 -0500 From: "Bruce Plecan" Subject: Re: DIY_EFI Digest V4 #651 - ----- Original Message ----- From: Laura & Neil To: Sent: Saturday, November 20, 1999 9:58 AM Subject: Re: DIY_EFI Digest V4 #651 91 is ecm not pcm. Grumpy | > Date: Fri, 19 Nov 1999 18:40:07 -0500 | > From: Darren Floen | > Subject: Speed sensor | > | > Hi everyone.A while back i was asking questions about fuel injection for | > a 4.3,being swapped into a Toyota.Well,i have now found a newer engine | > to use.I picked up a 91 4.3 throttle body engine,from a Safari van. | > | > So now i need a wiring harness.I contacted Howell and Painless.Howell | > says a speed sensor is not required for the engine to run smoothly.Matt | > at Howell says that it will only affect the EGR,and not the IAC. | > Painless says that the engine will always be stalling on deceleration. | > | > My question is this.How will the IAC motor reset its position if it | > doesn't have a speed sensor input?It is my understanding that this | > happens when the vehicle reaches 30 MPH. | > | > There is no smog testing where i live. | > | > So,do i need a speed sensor or not? | > | > Anyone know of any good websites dealing with 4.3 swaps and such? | > | > Thanks, | > | > Darren Floen | > Thunderbay,Ontario | > | | I assume this is going to be an engine and trans swap Darren | The stock trans for the late 4.3 G.M's is the TH700 or derivatives. This uses a PCM | controlled lock-up converter that is activated with the vehicle speed as one of the | inputs. | I'd say the speed sensor is very nessesary. | | Neil | ------------------------------ Date: Sat, 20 Nov 1999 09:42:57 PST From: "scott christensen" Subject: DIS Hi everyone. Just joined. I am doing research to roll-my-own DIS for a 4 cylinder aircraft engine. I would like to control the timing advance with a microcontroller based mainly on the MAP reading. (in aircraft RPM's stay constant but MAP changes drastically with altitude variation) A few questions for the group: 1) I like this CDI multi-fire MSD-6A unit (~$130). Is there a similar unit that can control two different coils simultaneously for a four cylinder engine, ala "waste-fire" style? 2) I found this waste-fire coil picture here on efi332: ftp://efi332.eng.ohio-state.edu/incoming/coil.jpg Anybody know what this coil is from? Specs? 3) Anybody out there roll-their-own CDI coil driver circuitry? (or use the "capacitive discharge driver" circuit from Zublin's MSD-6A article) Thanks Scott ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ End of DIY_EFI Digest V4 #652 ***************************** 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".