BoostedSUV
Active member
Re: relocating Ign module?
of course not, then I would have to reset my radio presets :roll: :lol:
of course not, then I would have to reset my radio presets :roll: :lol:
relocating Ign module?
- Thread starter BoostedSUV
- Start date
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Quickstop [UK]
Combating adversyty.
Re: relocating Ign module?
How big/old is the battery?
How big/old is the battery?
RealFastV6
@jb_and_his_coffee
Re: relocating Ign module?
If your battery is relocated, how did you ground the motor \ battery?
If your battery is relocated, how did you ground the motor \ battery?
The Bronze
New member
Re: relocating Ign module?
Battery Voltage:
Cranking over at 10.5V is enough to run the vehicle. 10.4V is where you would start replacing batteries. That voltage is AT the battery, not the voltage pid on datamaster though. Unless your vehicle is actually turning over slowly, I wouldn't be suspecting voltage being the problem. Also, you actually do have 60% battery at 12.2V, but that is a far cry from 12.6V though. I would start with the battery. Either your meter is wrong or there is a problem there.
Spark:
Have you verified weak spark? A spark checker is $20. Pull a plug or coil wire if lazy and see if you can get 20kV out of it. Not only will you take the coil out of the loop, but you will be able to judge the amount of spark you are getting. 3 per engine revolution is all you should be seeing. If you are seeing sparatic or lots of spark, You will now have a diagnostic path to follow.
If your computer is giving invalid rpm, then you certainly need to look at the rpm input from the ignition module (via the stator). I have seen cracked and magnatized stators cause similiar symptoms, but never a solid high rpm like that. If it were me, I would have a scope on the rpm input to the PCM, then back to the ICM and then the stator.
I will go out slightly on a limb and bet your PCM is doing it's best "garbage in, garbage out imitation".My bets are:
Stator (cracked or even magnetized)
Module
PCM
Battery Voltage:
Cranking over at 10.5V is enough to run the vehicle. 10.4V is where you would start replacing batteries. That voltage is AT the battery, not the voltage pid on datamaster though. Unless your vehicle is actually turning over slowly, I wouldn't be suspecting voltage being the problem. Also, you actually do have 60% battery at 12.2V, but that is a far cry from 12.6V though. I would start with the battery. Either your meter is wrong or there is a problem there.
Spark:
Have you verified weak spark? A spark checker is $20. Pull a plug or coil wire if lazy and see if you can get 20kV out of it. Not only will you take the coil out of the loop, but you will be able to judge the amount of spark you are getting. 3 per engine revolution is all you should be seeing. If you are seeing sparatic or lots of spark, You will now have a diagnostic path to follow.
If your computer is giving invalid rpm, then you certainly need to look at the rpm input from the ignition module (via the stator). I have seen cracked and magnatized stators cause similiar symptoms, but never a solid high rpm like that. If it were me, I would have a scope on the rpm input to the PCM, then back to the ICM and then the stator.
I will go out slightly on a limb and bet your PCM is doing it's best "garbage in, garbage out imitation".My bets are:
Stator (cracked or even magnetized)
Module
PCM
BoostedSUV
Active member
Re: relocating Ign module?
Its grounded to the frame, the from the frame to the block and the block to the firewall. It doesn't crank slow so I don't suspext grounds. Plus my old typhoon has this same issue and that battery wasn't relocated to the back.
Its grounded to the frame, the from the frame to the block and the block to the firewall. It doesn't crank slow so I don't suspext grounds. Plus my old typhoon has this same issue and that battery wasn't relocated to the back.
BoostedSUV
Active member
Re: relocating Ign module?
While I agree the voltage is at the battery my concern was the ECM only seeing 10Ish volts if that would cause crazy things to happen like weak spak, etc. The engine cranks plenty fast enough IMO that it should start.
ECM, Ignition module, and magnetic pickup in the MSD dizzy have all been replaced. I'm going to invest in a spark tester and see if I'm getting weak spark but why the ECM sees 6350 RPM druing cranking and dumps fuel is beyond me.
While I agree the voltage is at the battery my concern was the ECM only seeing 10Ish volts if that would cause crazy things to happen like weak spak, etc. The engine cranks plenty fast enough IMO that it should start.
ECM, Ignition module, and magnetic pickup in the MSD dizzy have all been replaced. I'm going to invest in a spark tester and see if I'm getting weak spark but why the ECM sees 6350 RPM druing cranking and dumps fuel is beyond me.
BoostedSUV
Active member
Re: relocating Ign module?
I'll ad another symptom to the mix. Truck at 180* idles perfect no matter what I do. Truck gets over 200* idle is speratic and wants to shut off if I take it out of gear, put it into reverse from neutral. I have to feather the throttle when approaching stop lights because it will try to shut off on me. The idle will just drop and off goes the engine.
I.e. Took it to work today, perfect all the way to work. Started to run a little hot (210ish) and it wouldn't idle smooth. Stopped to back into parking spot, almost stalled. Put it into reverse went 10 ft then stalled in the parking spot. Tried to refire it just to see and it just cranked, wouldn't start. Will go out later after work once its cool and it will fire right up with half a crank. :dunno:
Is there something the ECM does when it detects higher engine temp that will throw the tune off? It is absolutely the smoothest best running truck at normal operating temperatures. What changes when the engine runs a little hot?
I'll ad another symptom to the mix. Truck at 180* idles perfect no matter what I do. Truck gets over 200* idle is speratic and wants to shut off if I take it out of gear, put it into reverse from neutral. I have to feather the throttle when approaching stop lights because it will try to shut off on me. The idle will just drop and off goes the engine.
I.e. Took it to work today, perfect all the way to work. Started to run a little hot (210ish) and it wouldn't idle smooth. Stopped to back into parking spot, almost stalled. Put it into reverse went 10 ft then stalled in the parking spot. Tried to refire it just to see and it just cranked, wouldn't start. Will go out later after work once its cool and it will fire right up with half a crank. :dunno:
Is there something the ECM does when it detects higher engine temp that will throw the tune off? It is absolutely the smoothest best running truck at normal operating temperatures. What changes when the engine runs a little hot?
BoostedSUV
Active member
Re: relocating Ign module?
thats the voltage info I was looking for. as far as a leaky injector or reg I doubt that since the truck runs perfect until it gets hot then it doesn't want to start
thats the voltage info I was looking for. as far as a leaky injector or reg I doubt that since the truck runs perfect until it gets hot then it doesn't want to start
BoostedSUV
Active member
V6 Kompressor
New member
Re: relocating Ign module?
Did you have any success yet? I have the same symptoms with code 42 occasionally. I have replaced ecm's injectors, ign. modules eproms. About to run new ignition module harness to ecm. I have already re-pinned the ecm connector too. It seems to be a heat soak issue. Maybe re-locating the module will help.
Did you have any success yet? I have the same symptoms with code 42 occasionally. I have replaced ecm's injectors, ign. modules eproms. About to run new ignition module harness to ecm. I have already re-pinned the ecm connector too. It seems to be a heat soak issue. Maybe re-locating the module will help.
V6 Kompressor
New member
Re: relocating Ign module?
I have the msd distributor and 2 gauge power and ground cables going to all the important places, plus 2 x 8 gauge wires from alternator to battery. BUT, I also have a 22 amp electric cooling fan that could be putting noise on the power system, in being that this seems to be heat related. I will have to put a scope on the 12v dc power line and see if there is ac on it, the tach doesn't jump to 6300 rpm, so it can't be a tach input... could be a signal from the msd pick up coil, maybe.... when hot... let's solve this!
I have the msd distributor and 2 gauge power and ground cables going to all the important places, plus 2 x 8 gauge wires from alternator to battery. BUT, I also have a 22 amp electric cooling fan that could be putting noise on the power system, in being that this seems to be heat related. I will have to put a scope on the 12v dc power line and see if there is ac on it, the tach doesn't jump to 6300 rpm, so it can't be a tach input... could be a signal from the msd pick up coil, maybe.... when hot... let's solve this!
BoostedSUV
Active member
Re: relocating Ign module?
I haven't messed with the truck but mine too is definitely a heat related issue. The hotter the engine, the harder it is to start. cranks fine, just won't fire like its flooded.
I haven't messed with the truck but mine too is definitely a heat related issue. The hotter the engine, the harder it is to start. cranks fine, just won't fire like its flooded.
V6 Kompressor
New member
Re: relocating Ign module?
It def. has something to do with heat, I'm thinking the only item I have not changed out is the pick up coil in the distributor. I get the same 6300 rpm pulses with almost 100% duty cycles output from the inj. pw. I have replaced the connector and ran a new harness from the distributor to the ecm today. No change. I did add a switch to the Fuel pump relay circuit to shut down the fuel pump when I start up the engine when warm, that has helped stop the flood issue, but i still get a random code 42 and because the ecm sees 6300 rpm, it senses a discrepency in the pulses and will set that code. I have a new pick up coming from MSD, but maybe a stock distributor will cure this. I have also changed out the coil too. I could deal with this if it wasn't for the random code 42's, but I am stubborn enough to find this gremlin and put it out of my misery... here is the new parts so far, 3 ecm's, 2 eproms, 2 coils, 3 ign. modules, 2 sets of injectors, rewire harness, twice. new sensors (all of them), repinned ecm connectors, new grounds and power, new relays, new sensor connectors (map, iac, coolant temp, ign. module, ign coil, TPS, MAP, 2 ECM, 1 alternator, dist cap and rotor button and 1 set of plug wires... and lots of beer and time. During the summer, it was worse the hotter it got.
It def. has something to do with heat, I'm thinking the only item I have not changed out is the pick up coil in the distributor. I get the same 6300 rpm pulses with almost 100% duty cycles output from the inj. pw. I have replaced the connector and ran a new harness from the distributor to the ecm today. No change. I did add a switch to the Fuel pump relay circuit to shut down the fuel pump when I start up the engine when warm, that has helped stop the flood issue, but i still get a random code 42 and because the ecm sees 6300 rpm, it senses a discrepency in the pulses and will set that code. I have a new pick up coming from MSD, but maybe a stock distributor will cure this. I have also changed out the coil too. I could deal with this if it wasn't for the random code 42's, but I am stubborn enough to find this gremlin and put it out of my misery... here is the new parts so far, 3 ecm's, 2 eproms, 2 coils, 3 ign. modules, 2 sets of injectors, rewire harness, twice. new sensors (all of them), repinned ecm connectors, new grounds and power, new relays, new sensor connectors (map, iac, coolant temp, ign. module, ign coil, TPS, MAP, 2 ECM, 1 alternator, dist cap and rotor button and 1 set of plug wires... and lots of beer and time. During the summer, it was worse the hotter it got.
RealFastV6
@jb_and_his_coffee
Try hot starting it by jumping it.
I really suspect you have a battery relocation issue. My truck had a very similar issue when I got it. I didn't notice the rpms but it wouldn't hot restart. If I jumped it then it would fire right up.
I really suspect you have a battery relocation issue. My truck had a very similar issue when I got it. I didn't notice the rpms but it wouldn't hot restart. If I jumped it then it would fire right up.
V6 Kompressor
New member
Re: relocating Ign module?
After relocating the ignition module, the 6300 rpm spikes seemed to have gone away. I made an extension harness for the two external connectors and one for the mag pick up. I used a new mag pick up from MSD, a # 84661. I wanted to use a MSD Pick up cable that I had and splice a connector off a Gm pick coil and use it scince it had a lock on it to keep it attatched to the module. I used an AMD pc CPU heat sink and fan to keep the module cool and mounted it all on the right inner fender, under the hood. I think the reluctor is too close the the Ignition module and the reluctor induces voltages into the module's circutry, in the MSD distributor. The stock distributor's pick up coil is shielded for some reason, where MSD's isn't. Here are some Pics:
Drilled a 1/4 in. hole through the bottom and ran the wires through it, then sealed with silicone:
Bottom of heatsink with module mounted to it, didn't have a 6-32 tap, so hacked up the heat sink a little to get some nuts on the bottom. The heatsink needs to be grounded, also. :
Here is view sith the module mounted:
View of fan mounted and ground ran:
There are some more pics on photobucket. I am not convinced 100% that this is the fix, but i am going to drive it this way and see if the 6300 rpm spikes come back. At least the module is easier to get too. I left a module mounted in the distributor to keep water out.
Here is a link to Photobucket pic album where there are more:
http://s894.beta.photobucket.com/us...g.html?&_suid=135207817044006243112405219732
After relocating the ignition module, the 6300 rpm spikes seemed to have gone away. I made an extension harness for the two external connectors and one for the mag pick up. I used a new mag pick up from MSD, a # 84661. I wanted to use a MSD Pick up cable that I had and splice a connector off a Gm pick coil and use it scince it had a lock on it to keep it attatched to the module. I used an AMD pc CPU heat sink and fan to keep the module cool and mounted it all on the right inner fender, under the hood. I think the reluctor is too close the the Ignition module and the reluctor induces voltages into the module's circutry, in the MSD distributor. The stock distributor's pick up coil is shielded for some reason, where MSD's isn't. Here are some Pics:
Drilled a 1/4 in. hole through the bottom and ran the wires through it, then sealed with silicone:
Bottom of heatsink with module mounted to it, didn't have a 6-32 tap, so hacked up the heat sink a little to get some nuts on the bottom. The heatsink needs to be grounded, also. :
Here is view sith the module mounted:
View of fan mounted and ground ran:
There are some more pics on photobucket. I am not convinced 100% that this is the fix, but i am going to drive it this way and see if the 6300 rpm spikes come back. At least the module is easier to get too. I left a module mounted in the distributor to keep water out.
Here is a link to Photobucket pic album where there are more:
http://s894.beta.photobucket.com/us...g.html?&_suid=135207817044006243112405219732
Last edited:
BowTy
New member
Re: relocating Ign module?
I do think you not only nailed your problem, but confirmed research I have been into that has shown a common issue with the MSD dizzy, also happening to my Ty. I too have the MSD 8367 dizzy (new), and have tried 3 different MSD modules/pick-up to no avail. I set the pickup air gap properly (.015"-.035") but not help, so since there was little else to try, went with 050", condition got worse with more random high rpms at cranking, which for me confirmed it was in the module/pick-up arrangement of this MSD.
ChevyTalk forum, and here at MSD's forum: http://www.msdignition.com/forum/showthread.php?t=11886 talks the same wild rpm during cranking, though it's bad enough for the owner on the MSD forum to have it while driving/stalls. When I data log, I see 9,900 rpms (aftermarket ECM), sometimes 6,900 rpms, with the engine refusing to start with those values, until the rpms go back to normal cranking values (200-450+ rpms). This is really bad on an engine as it's caused mine to light off the spark plugs at the wrong time/when a piston(s) is coming up and well before TDC, enough to stop the engine and starter with a jar, voltage plummets as it's a near short-circuit for the starter having engine power pushing back against it :tdown:. There is no oil pressure at cranking so my rod and main bearings are not liking this at all!!!!
I won't get into the rest of the problems I went through trouble-shooting everything else in this fresh rebuild to find the problem (all grounds clean, tested and confirmed, related wires relocated, new battery, alternator, 10mm plug wires, you name it, I have gone through it all), but will say the replacement parts from MSD have no instructions as in using heat sink compound/thermal paste on the module base, and the last part I got today, missing the base, for the pick-up so it could not be used at all :roll:.
I too think its a design issue with the magnetic field bleeding over into the pickup feed wires, and your relocating it proves that to me :tup:, thanks, always good to confirm even what you are pretty dang sure about
. Earlier today (yesterday now) I was showing the little woman the wires, and how much fun it will be if (I keep this dizzy) I want to try and add shielding to those 2 pick-up wires and test if that does it, but I am now leaning towards.......Accel, I know, has a lot more bad press than MSD, but I like the idea of having ball bearings (bushing at the bottom) for longevity and such, or screw it and just get a new (or rebuilt) OEM unit.
Last thing is there is a slight miss, that I am betting is related, will find out and post back once I either get the Accel, or the AC Delco unit (and just because I am that way, confirm all over again the rotor phasing, and timing are accurate!).
Hope this helps others, I know it helped me, and thanks guys :tup:.
<snip>
I do think you not only nailed your problem, but confirmed research I have been into that has shown a common issue with the MSD dizzy, also happening to my Ty. I too have the MSD 8367 dizzy (new), and have tried 3 different MSD modules/pick-up to no avail. I set the pickup air gap properly (.015"-.035") but not help, so since there was little else to try, went with 050", condition got worse with more random high rpms at cranking, which for me confirmed it was in the module/pick-up arrangement of this MSD.
ChevyTalk forum, and here at MSD's forum: http://www.msdignition.com/forum/showthread.php?t=11886 talks the same wild rpm during cranking, though it's bad enough for the owner on the MSD forum to have it while driving/stalls. When I data log, I see 9,900 rpms (aftermarket ECM), sometimes 6,900 rpms, with the engine refusing to start with those values, until the rpms go back to normal cranking values (200-450+ rpms). This is really bad on an engine as it's caused mine to light off the spark plugs at the wrong time/when a piston(s) is coming up and well before TDC, enough to stop the engine and starter with a jar, voltage plummets as it's a near short-circuit for the starter having engine power pushing back against it :tdown:. There is no oil pressure at cranking so my rod and main bearings are not liking this at all!!!!
I won't get into the rest of the problems I went through trouble-shooting everything else in this fresh rebuild to find the problem (all grounds clean, tested and confirmed, related wires relocated, new battery, alternator, 10mm plug wires, you name it, I have gone through it all), but will say the replacement parts from MSD have no instructions as in using heat sink compound/thermal paste on the module base, and the last part I got today, missing the base, for the pick-up so it could not be used at all :roll:.
I too think its a design issue with the magnetic field bleeding over into the pickup feed wires, and your relocating it proves that to me :tup:, thanks, always good to confirm even what you are pretty dang sure about
. Earlier today (yesterday now) I was showing the little woman the wires, and how much fun it will be if (I keep this dizzy) I want to try and add shielding to those 2 pick-up wires and test if that does it, but I am now leaning towards.......Accel, I know, has a lot more bad press than MSD, but I like the idea of having ball bearings (bushing at the bottom) for longevity and such, or screw it and just get a new (or rebuilt) OEM unit.Last thing is there is a slight miss, that I am betting is related, will find out and post back once I either get the Accel, or the AC Delco unit (and just because I am that way, confirm all over again the rotor phasing, and timing are accurate!).
Hope this helps others, I know it helped me, and thanks guys :tup:.
V6 Kompressor
New member
Re: relocating Ign module?
I drove all weekend and no heat soak, flooding hot starts anymore. The engine starts right up now, no matter how long I've driven it and how long it sits in between when hot. It is now a pleasure to drive on errands... I did use a twisted pair (MSD) cable for the pick up and a shielded 4 conductor cable for the module 4 pin connector. the 4 pin Ign module connector is available on ebay. You know GM moved the ignition module out of the distributor and mounted it on the side of the engine starting in 1996 hmmm..
I drove all weekend and no heat soak, flooding hot starts anymore. The engine starts right up now, no matter how long I've driven it and how long it sits in between when hot. It is now a pleasure to drive on errands... I did use a twisted pair (MSD) cable for the pick up and a shielded 4 conductor cable for the module 4 pin connector. the 4 pin Ign module connector is available on ebay. You know GM moved the ignition module out of the distributor and mounted it on the side of the engine starting in 1996 hmmm..
BowTy
New member
Re: relocating Ign module?
Thanks for the update, and glad to hear yours is now driving like it should :tup:. Good point on observing that GM now uses a remote location for its modules to help with heat related issues. Exceptional approach using twisted, and shielding wires, bet you won't have anymore issues, and I am looking forward to the same in the next few weeks when I finish mine!
Thanks for the update, and glad to hear yours is now driving like it should :tup:. Good point on observing that GM now uses a remote location for its modules to help with heat related issues. Exceptional approach using twisted, and shielding wires, bet you won't have anymore issues, and I am looking forward to the same in the next few weeks when I finish mine!