DIY PROMDo It Yourself PROM chip burning help. No PROM begging. No PROMs for sale. No commercial exchange. Not a referral service.
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Wow, my very own sticky post. I feel honored. I'll start a new list. I still haven't sent out the first batch, still have one more thing to test and evenings are too short sometimes. I hope to finish testing today.
ok so wtf are we talking about so i can make sure if i want 2 or not lol, we talking about running a 4bbl tbi unit??? if so im in, ...what ecm do i need to do this, what re wiring?? any FAQ available???
An update for those of you who are wondering if I have dropped off the face of the earth or something.
There is one problem I have found with these boards. Briefly, with P/H injectors, the circuit drives them at a high current (about 3.5A) for a portion of the pulse, long enough for them to open reliably, and then reduces the current to about 1 amp. At the point when the current is reduced, there is a flyback voltage produced at the injector. Since this board was designed to use the injector drive signals to drive the additional injectors, that flyback voltage pulse, which is about 30V, gets fed into the board. When the board sees this voltage spike, it assumes that it is time to turn off the injectors, and does so. Then when the flyback voltage spike goes away, and the circuit sees that the injector should still be on, it starts the process over again. So, the injectors being driven by this board get two high current pulses instead of just 1.
The engine runs just fine, but I am worried that this may unduly stress the injectors or cause them to overheat so I am looking for a solution to this problem. I am looking at two possible solutions. The first, and easiest but most expensive, is to use two boards to drive four injectors. The second is to change the sense resistors on the board so that each driver output will drive two injetors, in parallel.
At the same time, I am also building an awning over my deck on my house and when the weather is nice, that takes precedence. So, your patience is appreciated. I have modified one board with the lower value sense resistors, and just need to wire it in to my harness and test it. I hope to get that done early this week.
Thanks for the update John. If everyone feels the way I do then we're just glad you're taking your time and trouble shooting to get things right. I personally am in no hurry so take you time whenever you can find it and a BIG thank you for even doing this for all of use. I just wish I had some of the knowledge and skills you have when it comes to electronics.
Steve
Last edited by steve8586iroc; 05-08-2003 at 09:19 PM.
OK. I think the boards are working just fine now. I have a bad injector, that I think has been bad for some time, so I can't test as thoroughly as I wanted, but I had one board driving four injectors for a while yesterday. I wired two injectors in parallel for each output, and had all four injectors running just like they should.
I will send out schematics and bill of materials, with instructions for making the board drive either 2 or 4 injectors.
Unfortunately, I installed McAfee virus scan and it deleted all my emails in Outlook Express (no joke, there is even a posting in their FAQ about this and how to try to retrieve them) so I will be emailing all those who want boards to get your addresses again.
Yellow73bb, would you put me on the list for 2 boards, 2 heat sinks and two connectors for you next run? Or if you have extras I will take them. I will e-mail you to confirm. Thanks very much...............bob
__________________ 91 camaro RS convert,GM crate 350 LT1 cam, 1.6 comp cams roller tipped rockers, edelbrock 6085 heads,9.5:1 comp, edelbrock TBI intake bored to 2", 90# injectors,454 TB, My own custom chip that I continue to modify, ramair dual snorkle cold air ,dual fan conversion, ultimate TBI mods,TBI spacer,SLP 1 5/8 headers,
3"cat back,SLP single 3" muffler,
T-5, centerforce 2 clutch( 1st one blew@4,000 miles), 3.42 torsen posi,alston SFC's,Global West LCA relocation brackets, edelbrock/ owner modified 2 point STB that allows ramair dual snorkel to clear.
Baer sport 12" front discs and PBR calipers. A little faster now, 14.26 @ 103.1 on streets on G-tech @ 6,000 foot altitude , car weight 3369# without driver and spare tire but lots of subwoffers. Now I am definitly gonna spray it........
I am prepared to build another run of boards if there is sufficient demand. In order to get the cost under $10 per board I need orders for 20 boards.
Just to reiterate. The boards have no solder mask or silk screen. They are cheaper that way in small quantities. So, you have to be careful when soldering that you don't bridge two traces. I think that is a small price to pay for having a small price to pay. Also, you can use the same board to drive either two or four injectors depending on which sense resistor you put on the board. I am running four injectors with one board.
I am also not going to supply the heat sinks. You can order the heat sinks and a plastic box from All Electronics. The part numbers are in the bill of materials.
If you want boards, please send me an email rather than posting on this thread and I will get boards made when I get enough orders.
john i dident get a parts list with my boards .
could you please post it or e-mail it to me.
the download up top dosent print the parts list
thanks
pete perfectsparks@aol.com
So far, I have received only one email for boards. If you want boards, even if you have posted to this thread that you want them, please send me an email with your address.
im curious if the boards could be used to make a TBI car multiport?
i was just thinking, lets say i put a multiport intake on my car. if i used the boards to pulse all 8 injectors, could i keep my entire TBI EFI electrical system and just make a plug and play connector?
imagine, just plug in where the 2 injectors go, and it would work all 8. then i just need a chip swap and bump the fuel system to multiport pressure and im all set.
High impedance injectors or P&H? With P&H it is just what you want. With high impedance ones, it is overkill. You could make it work by replacing the sense resistors with wires (so the circuit never goes into hold mode). You could also probably leave out the LM1949 and just jumper from pin 1 to pin 2 and make it work. Save some money too since the LM1949s are pretty expensive. I think all you really need for high impedance injectors is a couple of transistors to invert the input signals, and a couple more transistors to drive the injectors, plus a couple protection diodes (need some current limiting resistors too of course).
I am planning to try this in the fall, I'll post when I get it to work.
To those who have requested boards, there have not been nearly enough requests (less than 5) to warrant another build unless you are willing to pay quite a bit more for them. Therefore, I don't plan on building any more boards. If anyone wants the gerber files, send me an email, and you can make your own boards if you desire.
Originally posted by icecold if anyone is interisted i never used the 2 i purchased if anyone wants them e-mail me
i have
2 boards
2 cables
4 heatsinks
pete
Im game for one full set - one board and necessary peripherals.
Also, you can use the same board to drive either two or four injectors depending on which sense resistor you put on the board. I am running four injectors with one board.
