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PostPosted: Wed Aug 02, 2006 5:28 pm 
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Supercharged

Joined: Sun Jun 04, 2006 4:53 pm
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Location: Gaithersburg MD
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I have measured the voltage coming off the distributor pick-up tails and I am getting about 1 volt, slightly less, in pulses. The Accel ECM is not seeing this, as there is no RPM read out on the Calmap tuning screen during crank. When I take the coil lead out and hold it close to ground and crank, no spark. So it seems the problem must be in the ECM. The question is this, shouldn't a pulse of .95 volts be enough to trigger the ignition read in the ECM? The ECM is simply not seeing any signal from the sitributor. Anybody got any ideas here? I called the support line at ACCel, and they verified that the wires to the ecm are hooked up right. The fact that it ran for awhile, and then quit would certainly suggest that the wiring was right, and that now something is electronically wrong. I checked the continuity of the harness wiring as far as I could trace it, and it all seemed good. This has been a real bummer so far. I will call Accel tomorrow, and hope I get someone. If you have any bright ideas, let me know them. In the mean time I have a relativley attractive Dodge Dart sculpture in my garage. Maybe a next step would be to get Accel's Universal Inuctance Reluctor harness just to eliminate that as a source of trouble. I have it wired with an Advance Auto, univeral, three prong, GM weather-pack style plug, which might have a flaw in it that is intermittant.
I measured it again, with the VOM set for alternating current, and it reads. .3 volts. Maybe tht is not enough for the ECM to see a signal. Thanks guys. :cry:
Sam

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PostPosted: Wed Aug 02, 2006 9:35 pm 
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Supercharged
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Location: Portland-ish
Car Model: Fiat 500e
Sam,

Since you're becoming and expert at taking the distributor in and out take it out again. With the ignition switched on spin the distributor and see if Calmap shows RPM. If it does you should also get sparks and fuel injectors pulsing so you might just want to pull the fuel pump relay to avoid flooding. If you don't get an RPM indication pull the plug from the ECM and connect your AC volt meter across the pins where the distributor signal appears. Spin the distributor and make sure you see the voltage. If not you have a wiring issue. If you do then it's more likely to be an ECM issue.

I also have what may be a dumb question. Does the ECM have power when the engine is cranking? I had a friend of a friend put a TBI 4.3 in his '79 Malibu. It never would start without priming as the ECM lost power in the crank position.

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PostPosted: Thu Aug 03, 2006 12:09 am 
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Supercharged

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Location: Gaithersburg MD
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Hi Josh, you never have to worry about insulting me with a dumb question. I do have power in the crank mode. I now have a remote starter button, and can watch all this from under the hood, while it is cranking, and have checked that out. I appreciate your support here more than you can know.

I will check it out the way you suggested. Here are a couple of questions in return: Why is spinning it by hand any better then spinning it with the starter motor. Is it the speed you are looking for? Also, is this voltage of .35 enough to trigger the ECM, or do you suspect that the pickup might be insufficient? The thing that bothers me most here, and perplexes me, is that it ran for awhile, and then stopped. What the H--- could have changed about the wiring? Last night I supected the cheap Advance Auto connector, so cut that out of the harness, and doubled the leads back over for thickness and jambed each wire down into the female end on the Accel ignition harness to see if the connector was the problem. No such luck,! Still no spark, or RPM read. I have ordered a new pickup from advance auto, and will install it, but am not feeling at all optomistic any more.

I went on line and read the past threads on Accel's support e-mail, (which they no longer offer). doing a search for "NO SPARK". All of the suggestions offered there, I have already covered. They did not post follow up questions and answers in the threads, just the original question and first response. I will check the wiring with the meter as you suggested, and see if that is the source of the problem. Again, thanks for the support here. I was offered $9500 for this car last Spring, and right now, I am really sorry I did not sell it. I don't like feeling like I can't fix something myself, and I have definately gotten in over my head with the EFI thing, going all the way back to Mega Squirt. The documentation with the ACcel kit is very poor, compared to the encyclopedia of stuff on the Mega Squirt web site, which means studying Accel's "manual" isn't much help. There are too many "black boxes" in the wiring diagrams.

Right now, I feel like a whining PITA, and completely incompetent regarding this car. And, I know everyone out there has enough of their own problems in life without taking on mine. I know once it is running, I will get out of my slump, and feel differently. Thanks again for listening, and offering suggestions. Just having someone there to offer support is sort of keeping me sane. I hope I am not driving you crazy!
Sam

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PostPosted: Thu Aug 03, 2006 5:09 am 
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Did you try reversing the leads on the magnetic pickup? A stock Chrysler elec ign will often run for a while with the leads reversed, then stop running or become rough.

Lou

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PostPosted: Thu Aug 03, 2006 5:58 am 
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Supercharged

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I will dry reversing them. I had them apart several times with no way of knowing if I was putting back the same way. It would be easy to try both. I did try both pickups in this dual pckup distributor. I don;t know the difference. I see a very slight difference in timing on the two, and understand the adjustment on the reluctor gap is slightly less on one, but that should not keep it from running. Anyone know what the real idfference is? The new pickup I ordered is a single one, which has an application of an 85 d150 with automatic.
Sam

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PostPosted: Thu Aug 03, 2006 6:31 am 
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Supercharged

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Al at Accel's support phone line says the minimum voltage needed to fire the ECM's counter is .4 volts. That should explain why it won;t start. Also, I am going to get a battery charger and get the battery charged up. All this cranking has the battery down to 11.5 volts. I unhook it when not fooling with it to keep the radio and such from bleeding the battery down. I will let you know tonight or tomorrow if it starts, but Al seemed to think this was the problem. I will keep in mind Lou's suggestion as well.

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 Post subject: pickup
PostPosted: Thu Aug 03, 2006 9:26 am 
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Turbo Slant 6

Joined: Fri Sep 09, 2005 9:51 am
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If I understand it right, you're using a stock MoparHall effect distributor pickup?

If so, perhaps the most simple way to increase the signal is to run it to the stock Mopar ignition module and and connect the module's (-) coil output to IGN via a ~100ohm pullup resistor and take your ignition signal at the (-) coil line. That should make a nice strong 12V square wave that should trigger any ignition system.

The Mopar ignition module is overkill in this function, but it has 2 advantages - (1) you can connect it to a coil and run your ignition with it and (2) it's hard to get any cheaper


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PostPosted: Thu Aug 03, 2006 10:09 am 
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Sam Powell wrote:
Al at Accel's support phone line says the minimum voltage needed to fire the ECM's counter is .4 volts. That should explain why it won;t start. Also, I am going to get a battery charger and get the battery charged up. All this cranking has the battery down to 11.5 volts. I unhook it when not fooling with it to keep the radio and such from bleeding the battery down. I will let you know tonight or tomorrow if it starts, but Al seemed to think this was the problem. I will keep in mind Lou's suggestion as well.


.4 volts? You said you were getting .9 volts, so you should be good to go there.

Your problem reminded me of something I saw on the Megasquirt site, and KBB's reply is on the mark, I think. On some setups with the MSII, a 4-pin HEI module is used to create a nice square wave input into an ignition system. Note it is not used as the ignition controller; only to create a signal for another controller. I will shamelessly link a picture:

Image

Ignore the MSD stuff but look at the wiring on the 4-pin module. You have the leads from the reluctor, a switched 12v in, and the signal wire out, and that's it. Note the module *must* be grounded to work. Don't forget the 470-ohm 1/2 watt resistor across B and C.

You may have to reverse the reluctor leads going to W and G; and the wire at C is what you'll use to feed your Accel box. This same approach is what KBB is talking about.

The text for the article is at http://www.megamanual.com/ms2/msd6a.htm.
Apologies to MS for linking the picture, and max kudos to them for the information.

Hope this helps.

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PostPosted: Thu Aug 03, 2006 1:32 pm 
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Supercharged

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I was measuring it wrong. I was using the direct current setting of the meter. With the alternating side, it is only 3.5.

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PostPosted: Thu Aug 03, 2006 6:38 pm 
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Ill stop by next weekend to give you a hand with this....mebbe Saturday....

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PostPosted: Thu Aug 03, 2006 6:38 pm 
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Turbo Slant 6

Joined: Thu Jul 13, 2006 8:05 pm
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What kinda coil you using. It sounds like it may have craped.


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PostPosted: Thu Aug 03, 2006 7:50 pm 
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Supercharged

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Location: Gaithersburg MD
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Sandy, are you serious? Are you in the area for a delivery? That would be awsome. Ity would bre really great to meet face to face. Saturday is not good for me during the day, , but come late Saturday, spend the night, and play cars on Sunday. That would be awsome!

The coil puts out a pretty good sized spark when you ground and unground the trigger wire on the MSD, so the coil is good. I put in the new pickup tonight, and was smart enough not to try and start it tonight. I spun it by hand, and it put out a wide range of voltages, depending on how I spun it perhaps, or maybe the quality of my probe contacts,but it put out a high of .9 volts,with many of them in around.5 and .6. I don;t know how the speed of the spin affects the voltage During crank, it will be much slower of course, than spinning it by hand. It is now sitting there rough timed, and waiting for me to try it tomorrow. If the Calmap still does not see the pulse from the pickup and reluctor, then I begin looking at the wiring, and maybe a signal amplifier of some sort as is suggested in the Mega Squirt manual. Isn't that mega Manual something else? I can't believe what a job those guys did, and all volunteer. They must really love this stuff.
Sam

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PostPosted: Thu Aug 03, 2006 8:30 pm 
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Ill swing by on Aug 12 late....weel toon thet baby rideup.

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PostPosted: Thu Aug 03, 2006 8:32 pm 
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Supercharged
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Location: Portland-ish
Car Model: Fiat 500e
Sam,

I would try using the HEI module as an amplifier as in the diagram above. I know the Chrysler module will work with very low distributor speeds and I've turned a distributor back and forth slowly by hand and watched the sparks. The only problem is you'll probably have to use the Hall Effect input as your are creating a 12V square wave which is most like the Hall Effect signal. You can probably even steal power for the HEI module from the Hall Effect adapter.

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PostPosted: Fri Aug 04, 2006 6:03 am 
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Supercharged

Joined: Sun Jun 04, 2006 4:53 pm
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Location: Gaithersburg MD
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Apparently this Mopar distributor is just not going to cut it. I installed a new pick up module, and although I can get it to read.6 volts when spun by hand, in the engine it only puts out .2 volts at crank speed. This is measured at the input pins on the ECM as well as at the pig tails on the distributor. The Calmap screen still shows no RPM either on the digital readout or the tach dial. AL says .4 is the minimum to read. So something is needed hear to amplify the signal. I am going to study the MS diagram and see what I can do. One of the ignition selections in the calmap calibrations is for a GM HEI, so I assume that if I select this it will read the HEI signal directly with no further modifiers. Feel free to elaborate on this if you want to. Any and all advice, and feedback will be very appreciated. I am acatually feeling more optomistic the last day or so as I begin to understand how this all works. I still have a lot to learn. I would like to get it running before the Summer is out. Thanks for all your input.
Sam

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