Car simply does not stop running

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Jon k
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Car simply does not stop running

Post by Jon k »

Hey guys got the car running tonight again. I am running MSnS-E 029s on MS-1 V3 running a GM HEI in wasted spark with the HEI module bypassed using VB921s. If I remove my key from the ignition, the rest of thec ar shuts down (radio, lights) but the engine still runs... its so freaking weird.

I looked at the schematic for stock ecu (which is still in place controlling speed and tach, correctly too!) and it actually goes like this:

Wire from IGN Crank/Run -> Pin 1 on ECU (turn on lead?) -> Pin 56 out of ECU to Main Relay -> Main Relay switched +12v to MegaSquirt. Should I try bypassing the stock ecu relay turn on and take Pin 1 directly to the main relay? It seems the stock ecu is not closing the relay or something. I have to unplug MS to shut the car off.
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Post by Gokart »

Try unplug your main relay. You may only have a wrongly wired or faulty relay.
mkehler
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Post by mkehler »

Hey Jon, I had the same thing on my m20...maybe its a bimmer thing :). Solved it after advice from James to put a diode inline with the alternator 'charge' light. Note I totally ditched the factory harness, so there may have been a diode in there from the factory somewhere that I 'lost'.

http://www.msefi.com/viewtopic.php?t=21392&highlight=

Matt
Jon k
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Post by Jon k »

mkehler wrote:Hey Jon, I had the same thing on my m20...maybe its a bimmer thing :). Solved it after advice from James to put a diode inline with the alternator 'charge' light. Note I totally ditched the factory harness, so there may have been a diode in there from the factory somewhere that I 'lost'.

http://www.msefi.com/viewtopic.php?t=21392&highlight=

Matt
Hey thanks matt, but I noticed in the wiring diagram per Bentley, there is already an "uncoupling diode". What diode did you add and where? Also, I only have two wires coming from my alternator, did you have 3?

Edit: Sorry, should have read the thread completely - Matt, where is the charge light to snip? I don't care about having a batt light in the cluster, but where did you cut?
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Post by mkehler »

It was a blue wire coming out of the alternator, I just snipped and put the diode inline in the engine bay at a convenient spot. And I only have 2 wires out of there I believe.. I can check tonite.

Hope that helps...my GM coilpack will finally show up on Wednesday, so I'll move to wasted spark...and most likely be emailing you for more help :)

Matt
Jon k
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Post by Jon k »

mkehler wrote:It was a blue wire coming out of the alternator, I just snipped and put the diode inline in the engine bay at a convenient spot. And I only have 2 wires out of there I believe.. I can check tonite.

Hope that helps...my GM coilpack will finally show up on Wednesday, so I'll move to wasted spark...and most likely be emailing you for more help :)

Matt
No prob feel free to mail me -

However, here is the wiring diagram of my alternator. It looks like it has an "uncoupling diode" in place now?

Image

In the other thread you said you snipped a wire and then went back to put a diode in later, what wire did you snip initially? Was it at the gauge cluster?
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Post by mkehler »

Nope, it was the blue wire coming out of the alternator, I just snipped it in the engine bay. The m20 is in my '72 2002 with the stock 2002 gauge cluster...so I had just assumed my 2002 didn't have the diode in the cluster whereas the e30 did.

Matt
Jon k
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Post by Jon k »

mkehler wrote:Nope, it was the blue wire coming out of the alternator, I just snipped it in the engine bay. The m20 is in my '72 2002 with the stock 2002 gauge cluster...so I had just assumed my 2002 didn't have the diode in the cluster whereas the e30 did.

Matt
But if I snip that blue wire @ the alternator (im not even sure I have a blue one @ the alternator... but hte diagram says I should) won't I lose all power from the alternator? In the diagram it looks like the blue wire is what charges the battery, no?

Edit: never mind im an idiot and didn't read the diagram fully - so if I cut that blue wire (I am not sure if its blue, maybe its just dirty, mine looked black) what devices will lose power? It looks like its running all over the place in that picture but I am not sure.

So in truth, the alternator only has a B+ charge wire to battery (fat red) and the baby wire, so I should cut the baby wire? I guess alternator is grounded thru engine block.
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Post by mkehler »

I think the blue wire (on mine) was simply the charge/alt light in the gauge cluster, but for whatever reason it was backfeeding power and keeping everything running (I had to pull the coil wire on mine to get the engine to stop). As soon as I cut it (or put the diode in) problem solved. I think the blue was 16ga or 18ga.

When I snipped the blue everything else seemed to act as it should, and nothing else lost power. Except I no longer had the charge/alt light come on with the key was at ACC

Matt
Jon k
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Post by Jon k »

mkehler wrote:I think the blue wire (on mine) was simply the charge/alt light in the gauge cluster, but for whatever reason it was backfeeding power and keeping everything running (I had to pull the coil wire on mine to get the engine to stop). As soon as I cut it (or put the diode in) problem solved. I think the blue was 16ga or 18ga.

When I snipped the blue everything else seemed to act as it should, and nothing else lost power. Except I no longer had the charge/alt light come on with the key was at ACC

Matt
I'll be trying this today :) I will le tyou know how I make out.
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Post by jsmcortina »

Be careful, if you snip that wire you will need to rev the engine before the alternator starts charging. Indeed, you might find that it never starts charging. The light and wire are there for a reason.

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Jon k
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Post by Jon k »

jsmcortina wrote:Be careful, if you snip that wire you will need to rev the engine before the alternator starts charging. Indeed, you might find that it never starts charging. The light and wire are there for a reason.

James
I see - but james, that diagram clearly shows an uncoupling diode... is that not what i'd be adding anyway!?

Also, other than looking ridiculous - anything wrong with having to unplug the MS ecu to shut the car off? I can live with it like that until I figure out why.
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Post by Gokart »

Pulling your socket might induce spike which is not healthy for your cpu. I suggest you to install an on/off switch in-line with your 12V supply to MS instead disabling the relay.
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Post by jykä »

Hi Jon,

i have the same problem and it started after i installed spark side to my MS (before was just fuel-only). Havent had time to figure out to problem but my solution is to press brake pedal same time as i turn off the ignition. That is the only way to brake power from MS ECU ... wierd :D
Jon k
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Post by Jon k »

jykä wrote:Hi Jon,

i have the same problem and it started after i installed spark side to my MS (before was just fuel-only). Havent had time to figure out to problem but my solution is to press brake pedal same time as i turn off the ignition. That is the only way to brake power from MS ECU ... wierd :D
Jyka - ME TOO! I never had this issue with fuel control, just spark. I will try the brake pedal trick. Do you hold it then turn the key off or do you hit them both at the same time
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Post by jykä »

Jon

It doesnt matter which order you do it, but engine stops just after ignition is off and brake is on.
Best to do it simultanius, i think.
Jon k
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Post by Jon k »

jykä wrote:Jon

It doesnt matter which order you do it, but engine stops just after ignition is off and brake is on.
Best to do it simultanius, i think.
Weirdness... argh.
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