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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I've found where I can order the Aluminum I need for making an adapter. I should have enough to make 3 or 4 of them. Once that has been completed, and I've built my own Opti/HEI Dist, I'll send a couple of the adapters out for testing to ensure it works. I have some already in mind for this if they're willing. As my engine is completely stripped down as well as my Camino, I can not accomplish this myself. Once this is accomplished, I'll take 69 Ghost up on his offer.
Bill
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I wouldn't worry about throwing on a stepper IAC on a PCM that didn't come standard with a stepper IAC. There are a lot of stepper motor drivers out there. Take a look at the DIY Megasquirt EFI ECM and the IAC circuit to get an idea of what is involved.
The most difficult part is tracing out the ECM PCB to find the extra pins to use. I don't think Ludis' has that ECM listed. Along with the difficulty is figuring out the existing stepper motor code and converting to the bi-polar type. I don't think the adding the bi-polar stepper code will be that bad. I think the hardest part will be figuring out the existing IAC code. Ya never know, it could also be easier than expected.
elcamin0_77us,
Is the target HEI distr. a small cap or large cap?
junkcltr,
In my last post I am not talking about chaning the code or modifing the PCM. I am talking about an external converter circuit to drive a standard stepper motor IAC with the ISC motor signal the PCM outputs.
I see. I don't know how GM operates the ISC but I will take a guess at PWM. Not sure what it would take to convert the PWM to an H-bridge looking thing. Almost sounds like a calibration would be necessary. I will take a look at what you wrote about converting the signal.
The ISC motor is not controlled with PWM. ISC is controlled with a simple straight DC voltage. The direction of the ISC motor plunger is controlled by the polarity of the power going to the motor.
Originally posted by elcamin0_77us I'm going to use a Small Cap, IMO this should work great.
Bill
I just bought an Opti-spark off Ebay. I'm going to try to retrofit the guts into my large cap HEI. If successful (hopefully) the LT1 PCM conversion will be suitable for both setups then!
Originally posted by ULTM8Z I'm going to try to retrofit the guts into my large cap HEI.
I've got a couple of Large Cap HEI's that I've already disassembled. From what I see the inside of the dist housing would have to be machined flat. It also has a raised section (where the ignition modual mounts) that would have to be filled. The Small Cap HEI's from what I have seen in pics has a flat surface allowing easy mounting of the Opti's Base.
I'm going to try and start machining the Opti Base tomorrow at school/work. I'll take before and after pics. This way if everthing works I'll be able to creat a guide for others.
Originally posted by Craig Moates Actually, I was jumping ahead I suppose or back or sideways or whatever. I'm talking about a non-opti-spark system. Something that uses a different pick-up rather than optical and encoder wheel. Optical is one thing, LT1 is one thing. I was thinking more generally, if you could go toward something more DIS in nature eventually. It'd be nice to see some crank trigger options that are coupled with stock PCMs. Put some decent electronics between the trigger wheel sensor and a trigger box, and get rid of the distributor altogether. One less moving part to worry about. Just trying to think outside the box. Something like a 'DIS Translator' for stock PCMs.
You know Craig, I was working on doing just this but $$ got in the way. I have a eDIST, I need the LS1 or LS2 Coils, A crank trigger and a Cam sensor. I think the eDIST will work out well...
__________________ -=Jeff=- 1989 Corvette CoupeFOR SALE 1990 ZR-1 (New Project)
Originally posted by 89 Iroc Z The ISC motor is not controlled with PWM. ISC is controlled with a simple straight DC voltage. The direction of the ISC motor plunger is controlled by the polarity of the power going to the motor.
So it is more uni-polar. The means one single controlling direction. I am curious as to how you make up the other signal for the other coil. Not saying it can't be done. Is there already a circuit out there that does the conversion?
Originally posted by junkcltr So it is more uni-polar. The means one single controlling direction. I am curious as to how you make up the other signal for the other coil. Not saying it can't be done. Is there already a circuit out there that does the conversion?
It is two directions in and out. The ISC just has two wires going to the motor. Apply a DC voltage one way to move it out the plunger, reverse the polarity to move the plunger in.
Yes there are a lot of stepper motor driver circuits out there that could be made to work, the one 91L98Z28 posted would work with little modification. The stock IAC driver out of a ECM may be an even simpler way of doing it.
I got the Opti Base turned down today at work. Now I just need to get ahold of a Small Cap Dist. core to tear down. The local parts store is keeping in eye out for me.
The small base HEI's can be had for very cheap. I have an extra if somebody is looking for one. I paid $30 at the yard and would pick another one up next time I am out there.
Also the LT1 PCM's have flash chip that gets corrupted if the flash crashes when you upload it. Some of the LT1 sites replace these with I believe a plugin chip. If that can be done then I am sure Craig can rig up an emulator to replace the chip if thats what is wanted.
Originally posted by elcamin0_77us I've got a couple of Large Cap HEI's that I've already disassembled. From what I see the inside of the dist housing would have to be machined flat. It also has a raised section (where the ignition modual mounts) that would have to be filled. The Small Cap HEI's from what I have seen in pics has a flat surface allowing easy mounting of the Opti's Base.
The junk yards around here want to charge dearly. I can get a core from the parts store cheaper than I can buy one from the junk yard. I called about a small cap HEI $110.00 from junk yard. $50.00 from parts store.
730 tpi, I wasn't trying to be short. If I came acrossed that way, I'm sorry. I was just in a hurry. After I got home and checked the post, I realized it may have came off that way.
Here is a pic of the opti base while still on my make shift lathe. This works very well and would allow others to complete this cheaply as well.
I am interested in how this works out. I use a small base HEI and would like to go to the LT1 PCM for the trans control alone. Using a 80E trans would be much better than the TH350 in it now. The SEFI would be an added bonus.
I checked to see what kind of problems I would have if I used the Large Cap HEI late last night. As I had visioned, the inside of that dist needs to be flate. One might be able to pour some type of epoxy into it to level it off. Although I'm not sure that would be a good idea. I believe the best method would be to continue as planned and use the Small Cap HEI
just poiting something out. if someone here had the where withall there is enough unused i/o on the quaddrive modules if you sacrfific some output feature on the 730 for it to run SEFI with a outboard driver. there is also an unused a/d input for a cam or other timmer based sensor
Nice job on the distributer and thanks for the picture. I'm going to start messing around on one of my large cap HEI distributers that I have laying around. Does this seem like a very possible swap? - Justin
Being unable to find a Small Cap HEI around here for some reason, I've been thinking about it the last few days between classes. There seems to be two areas of concern.
1. Mounting the Opti base inside the Large Cap would require the following:
a. The area under the mounting pad would have to be filled. This could be easily done by welding.
b. The inside would then be "cleaned-up" with either a lathe or you could even use a die grinder, to allow the base to set flat. NOTE: Being careful of the area where the Cap fastens. Both the Carb & EFI versions have indentions under the base for the cap.
c. The bushing in the top of the dizzy would either be removed completely or just shortened. I think the latter would be best to help ensure proper alignment.
2. With the Small Cap, the rotor slides on the top of the shaft. On the Large Cap, the rotor bolts to a bracket. In both cases the height of the rotor is set. This is the area in which I'm still trying to completely work out in my head.
a. Machine a collar that bolts to the Opti base and has set screws for the shaft. The top of the collar would have to have provisions for the bracket that holds the rotor. This would require an exact height for the collar.
Originally posted by Grumpy They both use mathmatical modeling so the arguement about one being more *direct* then the other is nonsense. Either type is no better then the tuning.
Have Lingenfelter or Baecthel written any code, and spent alot of time looking at the code end of things?. Obviously not, since they both make the same errors, and misstatemtents.
GM for reasons of OBDII added a MAF back into the system. The MAPs were doing just fine.
Not asking questions is just following the herd, and get the *sport* no where. BTW, I've been to a few GM classes, and have had instructors recant what they've said.
MAFs have a inherit error in that they report not only the engine air flow, but the air reguired to change the vacum level in the manifold. In the later codes a fair amount of code is used just to correct this error.
you read the uncompiled C library ? i have. Its not working the way you think it is.
Can you post a pic of the cover? Does the cover fit over a moates adapter/tall ZIF/EPROM combo? If so, that'd be rather nifty for those of us not doing emulation who would rather not remove the ZIF from the adapter every time we want to put the ECM away (with the cover on it) for a few weeks...
Quote:
Originally posted by ULTM8Z Here's the ECM. The EPROM carrier actually protrudes out the top of the case a little. However, the cover is bubbled up to clear it.
Originally posted by funstick want pictures of our car running an lt1 pcm on a classic SBC ? give me 30 more days. waiting for machine work to finish up.
i thought i would mention for those who are thinking about using the 2240 the only ADS file for TunerPro i found for it is incomplete & there are some things that don't read right, so there is some work to be done there.
Originally posted by Grumpy Post it, let's see how it is working, then...
BTW, let's see where it is, that you say, I'm saying how it does work.
i'm not getting into this with you again. But if you dont belive i havewhat i claim to, just ask pablo. he can confirm that i have what i say i have.never mind i sent an email to someone who should forward it to you. oh and stfu
Originally posted by funstick i'm not getting into this with you again. But if you dont belive i havewhat i claim to, just ask pablo. he can confirm that i have what i say i have.never mind i sent an email to someone who should forward it to you. oh and stfu
LOL, gotta love the way some folks make claims, and then when asked to back them up, they just go into full dodge mode.
You made the claim, you allegedly have the info,. so post it or admit your really are just playing some more of your lame arsed games.
For all your arrogance, you still ain't posted diddly in the way of anything resembling being new data.
Not to mention one has to wonder with your command of the english language, if you can even understand what it is you do read..
Originally posted by 91L98Z28 Hope nobody minds a brief/temporary hijack:
Can you post a pic of the cover? Does the cover fit over a moates adapter/tall ZIF/EPROM combo? If so, that'd be rather nifty for those of us not doing emulation who would rather not remove the ZIF from the adapter every time we want to put the ECM away (with the cover on it) for a few weeks...
Sorry about the delay in getting back to you!
Mrs. ULTM8Z had our first baby last week- haven't had a chance to do anything else except tend to the two of them for the last week.
Anyway, just checked this thread for any progression and saw your post.
The bubble is 7/16" tall. The chip protrudes out the top of the ECM by .500".
BTW, I'm having a devil of a time trying to locate an LT1 powered vehicle in the boneyards...
Need the PCM connectors and an Opti connector.
I just looked under the hood of my '96 Tahoe and the PCM appears to have the same mechanical construction as an LT1 PCM. Is that actually the case or is it slightly different? It might be a lot easier to find a Chevy/GMC truck and get the connectors from it rather than an LT1.
Still would need an Opti connector, or a compatible substitute.
I think the trucks just might be the same, can't hurt to grab some as long as they don't charge you a ton for them. As for the Opti, that is a freak connector, the only one available, and the short pigtails are a little pricey from GM, in addition, there are two version, for the early, and for the late. One good thing though, is that if you are planning to use the guts in a small distributor body, you can get away with a regular 4 pin connector, similar to/exactly like a late model IAC. The Opti connector has basically an extended body, that goes through the cap, to the Optical pick-up assembly. Taking that piece out, makes the connector much shorter, and you can use a standard late model IAC. I say IAC, becuase I don't know off the top of my head, the offical 'name' of the connector, maybe 'metri-pack'
Looks like 3 of the 4 main connectors will work. The "black" connector is smaller on the truck PCM (24 pin vs. 32 for the LT1 as it appears). Also, I can't tell about the indexing tabs, they might be different.
edit:
from what I can tell, the "indexing" tabs (that keep the plugs from being plugged into the wrong connector) are the same for the other 3. Maybe some other application would have the right connectors? Might look for a Cavalier, grand am, or something like that. I'll look through what I have here and see what I can come up with.
Last edited by JP84Z430HP; 12-15-2005 at 10:18 PM.
I've gotten most of the dist housing hogged out, Had to stop for a couple of family emergencys. Started back on it yesterday. Found a machine shop here I believe that I can get to make the collar.
why doesn't anyone just mount a 95+ opti cover to a gen 1 block? The top water pump drive section can be cut off and it modified so that it has the same shape as the gen 1 cover. Mount a 95+ opti pickup and be done with all of the HEI modding problems
You're right, it could be done alot easier. Only one problem, the Opti-Craps keep going out due to all of the moisture in that area. You end up with the same problem that all the guys with the LT1's have. R&Ring Opticraps on a regular basis.
Will it fit underneath the pump and can it be made to work? I never thought it could be made to work that way. If you remove the dist and put an Opti in its stock location on a Gen I I would think that would be the way to go. I would not be so concerned about the reliability.
