Why won't the car start (spark issue)?

[bobafett]

Ok guys, time to help me troubleshoot this issue:

My car has an MSD 6A ignition, and MSD blaster SS coil. I have an 8.5mm MSD plug wire going from my coil to my cap. I am using some 7mm accell loaner plug wires my neighbor had on his mustang from the cap to each spark plug.

This exact setup has ran perfectly fine in the past, with no apparent issues.

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When I try to start the car, with the timing light on the #1 plug wire, I am getting NO spark to it. In fact I am not getting any spark out of the cap. My coil is definetly cranking out spark, if I pull the plug wire off it will arc to the body, so I know the coil is working.

Also if I take the plug wire and install it into the coil, and leave the end that is SUPPOSED to go to the cap free, it will still arc around and ground out... So I know the MSD wire is not faulty. Also, we put the timing light on this wire when trying to start, and we did get the gun to flash at us.

Another strange thing is that from the time I start cranking the car over, to the time the wires will arc out to ground seems to be significantly delayed, like over a second. I WAS thinking maybe it just needed enough voltage available to make a much bigger arc than it would normally need to throw a spark. However when I have the timing light on the coil to cap wire, it takes almost a second of cranking on the key before I see any flashes from the timing light.

Now I cannot explain the wierd lag issue, but the spark not getting out of the cap to each plug wire 'seems' like it would be a plug wire problem, or possibly a problem with the cap and/or rotor. The cap and rotor are new from when I put my motor back together, and the plug wires are the same as before too. So nothing has really changed at all.

I haven't pulled the cap to inspect the rotor yet, but I am willing to bet it is FINE. The whole system worked great when I pulled the motor apart, all I did is yank the dizzy right out of the head before I pulled the head, and the dizzy just hung out for a few weeks until I got it all back together. I never had the cap off to tweak at anything, so it seems unlikely to me that the cap/rotor/wires are truely the issue.

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Now, there are a few things I have changed since the last time the motor was together and trying to run, maybe you guys have an idea if any of this could have an effect on how it might run...

I rewired an 86-87 style TPS plug onto my 88-89 TPS (I have an 89, but I am using an aftermarket throttle body that needs an 88-89 style TPS). Also I removed a bunch of shit from my mystery vaccum box. Mainly the EGR valve, and AC idle boost valve.

I plugged in my old friend the IACV since I figure I will need all the help I can get, making this car idle.

I had to rewire one of my engine coolant temperature sensors, because the wires broke on mine (could backwards wires cause this bizzare issue??)

Now I am assuming there isn't any vaccum lines on the car that could affect the ignition system, but I did pretty much redo all of my vaccum lines because of the intake manifold I am using.

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So I am definetly at a loss for why I am getting spark to, but not out of the cap, and why the hell the spark seems to be delayed.

Any ideas?

[Oldblueaccord]

MSD 6A i assume its the analog units ? I dont feel there reliable I would look there. Is there some test you can do off the MSD web site ?

Only thing I could think of quick would be put a stock dizzy in there and see if it will start.

Im a little interested on how or what pickup you are using to trip the MSD there maye be a loading issue with the ignitor.


wp

[bobafett]

I AM using stock dizzy, but the MSD is just my ignition module and coil. I followed the wiring diagram on 3geez to get it hooked up, and it has been installed and working perfectly for 3 years. I 're' wired it when I first put the engine back in, and it worked ok then too, but I haven't touched the wires since then.

I suppose it is possible (but unlikely) that the CAS (cam angle sensor) wiring that triggers the 6A is funky, but I doubt it, cause I never messed with the wiring at all.

[A20A1]

I had starting problems once and it turned out to be my air gap. You are supposed to unscrew the stator (the two tabs) and slide them side to side untill the gap between the stator and reluctor are equal on both sides.



Problem is with my air gap is something kept exploding inside of my TEC distributor... not sure what it was but it would pop and only one side of the stator would be bent away from the reluctor. I think also the bearing could have been going out. But it also happned on my remanufacture TEC I bought.

good thing I had a hitachi to fall back on.

Also when opening one of my old TEC distributors I saw that the spring on the mechanical advance was totoally loose and offered almost no resistance to the weight throwing itself outwards at low rpms.

https://www.3geez.com/forum/showthread.php?t=53918

[Oldblueaccord]

I AM using stock dizzy, but the MSD is just my ignition module and coil. I followed the wiring diagram on 3geez to get it hooked up, and it has been installed and working perfectly for 3 years. I 're' wired it when I first put the engine back in, and it worked ok then too, but I haven't touched the wires since then.

I suppose it is possible (but unlikely) that the CAS (cam angle sensor) wiring that triggers the 6A is funky, but I doubt it, cause I never messed with the wiring at all.

Any chance you change the tach or the way the tach was wired is another thing I was thinking could effect it.

Im not sure how you could test the trigger when the dizzy spins maybe with a meter set on ohms I m thinking and see if it being accurite and what the reading is and what the MSD needs to fire correctly.

Sorry other wise.

the MSD is fine for what it is but if you notice like in NASCAR the run two redundent and look how often they switch to the back up in a race. I think you can send it back to MSD and theyll rebuid it. I would go digital if its bad.


wp

[bobafett]

well the MSD seems to be working fine, and the coil seems to be sending a really hot spark. it will arc to the chassis ground if there is no plug wire on the coil. if you put the wire on the coil and put it near the chassis it will throw a hot spark then too.

we pulled out a plug and tried to crank it, and there is a spark, but it's super weak... like hold the wire in your hand while it sparks and not worry weak.

i painstakingly setup the stator and reluctor on the dizzy i rebuilt (which didnt work at all afterwards) but i will double check the status on the one i am using currently. the thing is, the msd and coil are getting signal, and its even a strong signal out of the coil, but it seems like the spark gets REALLY weak between the coil and the plug.

now if that is the case it would seem that the cap/rotor would be the only cause of problems. but we tested resistance on everything, and it seemed to check out. one thing we are not sure of is if the car is firing once for each cylinder, or once for each tdc. maybe the cylinder sensor in the dizzy got messed up?

i am pretty much out of ideas, after i check the air gap, and replace plug wires/cap/rotor.

[2oodoor]

From what your writing I gather you are reluctant to pull the cap off and check the relation of the rotor and cap. I ve seen these things burn a hole through the inside tower for coil secondary wire.
The suggestions to check cam sensor and ignitor sound reasonable too, if there is something switching coil primary once steady resistance of secondary is detected. Be careful with testing that thing without secondary resistance , it will fry the ignitor (or controller what have you)
You did some swapping did you ensure you have a good heavy ground cable>>engine block to batt,batt to body, engine to body<<
Hope you get it figured out, I am curious what you find as well.

[bobafett]

oh i have pulled the cap and rotor and looked at them. they look pretty much like new. however there are a couple of spots on the contact on the inside of the cap that look like they have been scraped by the rotor spinning and rubbing on it. im not sure if that is a serious problem or not, but i AM planning on buying a new cap and rotor today just to be sure.

as for grounds, i have a 'unique' setup, but it worked in prior months, so i don't know why it would suddenly stop working.

i have an optima red top in the hatch of my car. and my negative battery cable goes directly to the inside of the frame rail. i am using 0 gauge cable for this connection.

my only other big ground is from my stock ground strap location that went to the valve cover, and i have it going into the head. that connection is either 2 or 4 gauge wire, its another really beefy connection.

i 'cant' get a ground from the motor to the battery, cause i dont want to run another 15 foot run of 0 gauge cable, its too expensive, and my frame grounds have proven to be VERY clean so far (according to all my testing anyway).

i dont fully know how to check the cam and cylinder sensor, but i suppose i can check it out in the book and see what they say....

is there any specific locations that need to be grounded? i would be happy to build some more ground cables.

[szvosec]

Is your tranny grounded? That probably won't help the problem, but I noticed on my car there was a ground wire on it too.

[bobafett]

is it the bronze/brass/gold colored bracket with a bracket on it that has a threaded hole in it? in that case, mine doesn't have a ground run to the chassis, but i did test resistance between that and the chassis, and it was basically 0. so its grounded through my engine ground. but i agree it cant hurt to run another, although i am sure it will not solve the problem... since i didn't have that ground there previously, and the car 'ran' ok.

[szvosec]

Yeah that sounds right. I couldn't get a good picture of it, too many hoses in the way. Hopefully your new dizzy cap, rotor, and wires fixes it

[bobafett]

yeah i know the spot you are talking about. i removed that ground when i moved all of the battery wiring. might as well add another though.

anybody else have any ideas on what might cause weak spark between the coil wire and the plug (cause i am still assuming the cap and rotor are still good)?

[2oodoor]

Keep in mind just because it worked before doesnt mean it still would, things may have fallen out of operational range, electronics.
I have my own philosophy, well borrowed actually, when it comes to OBD type problems...KISS,( means )keep it simple stupid
never take for granted the basic condition of parts that fall under preventive maintenance inspection, plugs, wires, battery and electical connections, vaccuum lines, sensor connections and such.
I would pull all the plugs out and see if they may be fouled or damaged. A plug could be grounded and with a non OEM high tension spark wire, you could get a false test showing no secondary from cap. Accel wires are ok, I would not say best or better what have you, but they are known to be counterfieted and mass produced. I would make sure there is a good ground from batt to block, dont count on the unibody to ground your powerplant,things move and flex while youre riding.
Check your tps voltage at idle, it should be 0 to .5 volts. , key on ign but NOT running ok, then check the voltage as you give it thottle, engine NOT running but key on ign. it should gradually rise up to 5.0 volts max. You may have to search the forum or manual for correct wires to hook DVM to for the test. You swapped something there right?

[Vinny]

Just a thought if you have strong spark going to the dist but dont have it out of the dist to the plug. Have you put a meter on the plug wires just to see if they are good? That would atleast eliminate 4 possible problems and narrow it without a doubt to something in the dist be it the cap rotor or the diist itself

Bare with me if i missed something, been a long night fighting with helicopters

[bobafett]

every wire has been checked, and had between 5-15 ohms of resistance, which is just fine.

i agree, just because it WAS working is no guarantee that it will still work, but I am having a hard time figuring out WHY its not working. i didnt get a chance to pick up my parts yesterday, so i am hoping to give it another go tomorrow.

as for chekcing the tps, i don't see how it would cause the car not to start. as a test, why doesn't someone with a running efi 3g unplug their tps and see if the car starts....

[Tecknixia]

Maybe the rotor came loose?

[2oodoor]

Cuz I wish you lived closer I would come over with my fluke and brick and run that puppy down. But all I can do is go by what you say and offer up ideas, its hard to fix cars with out touching or seeing them but I do it all the time. I can say this, the hardest ones to fix remotely are the ones some has done something to , or changed something. I mentioned the KISS, if you have gone through all of those items good, then lets separate the likelyhoods of the origin of the problemoe. Something you have recently done ..you are going to need an interface to see what the computer is seeing. The only other route would be knowing the specs and ranges on the sensors/controls you have been working with recently and testing them individually with a fluke meter, check the wiring to them where you spliced. Have you disconnected teh battery since you changed the parts? you have to reset the PCM so it knows you changed something. hope this helps

[shepherd79]

is your ignitor good? go to junk yard and pull another distributor for testing.
may be your ignition module is done. I know when i had crane ignition i was burning them at least one a year.

[bobafett]

The battery is disconnected 90% of the time. I hook it up only when I am going to try to start the car (mainly cause I will leave a hatch or door open, and I dont want to kill the battery).

My rotor is definetly not loose, it was on there really good, infact I even took some sandpaper to the post it slides on to, to make it a bit easier to pull off of there.

My distributor is 'new' from a junkyard because the original distributor I was using had a frozen advance, due to rust/old age etc. I took it all apart and put it back together after everything was moving properly, but the car would not run right. So I went to junkyard and grabbed a really nice clean looking dizzy that was so new it still had the sticker on it from the store. I'm sure it was a reman, but it hadn't been on the car very long. Anyway, THAT dizzy seemed to work great for the other times I have had the car running since this project started (limited times running...).

I have certainly done a lot of rewiring and cleanup on the wiring, and I would certainly understand if things like my MSD, or coil started to act up. But all the clues I have, indicate that those components ARE working properly. Its not like I can hook up my $30 voltmeter to the coil and test the 50,000V heheh. The fact that everything up until the cap distributing spark seems to be working, with strong spark and all, seems to indicate that even though I messed with wiring, its the same as it has been for years, the only thing I have done recently is shorten wires and run the negative wires to new grounds. I didn't really change the configuration of any of the wires (at least ones that could/would affect starting or running). Another fact is that up until this time around, the wiring did not pose a problem, and when I actually had the motor put together, the car would run.

I didn't get a chance to get the parts yesterday, cause the people at my shop are lame, but again, I am HOPING to pick up cap and rotor tonight too lol.

[2oodoor]

hopefully the cap and rotor fix it, your getting primary so that sort of rules out PCM or ECM , but sometimes different configs can control spark. I am leaning towards what all everyone has discussed , with the possiblity of ignitor or controller whichever you are using. I would not have done any sanding on the shaft, the rotor buttons are suppose to fit tight, sometimes so tight they break trying to take them off, thats why they sell new ones

[bobafett]

well there was some surface rust on the shaft, i just scuffed it up a very small bit. it still fits very snug. you have to rock it back and forth to pull it off, it won't just slide off.

[shepherd79]

you can take your ignition module to advance and they can test it for you.

[bobafett]

**AHEM**

don't know why I wasn't getting spark before... but it turns out there was a whole lot of other stuff wrong, which has since been addressed, and now I need to fricken learn how to time this thing.

as for the solution that made the car run..... wellll....... i have changed that head out so many fucking times, i forgot that when i removed the head i was using a stock cam, but when I put it back together i was using a 282 cam. turns out the 282 has a bit higher lift, so all of my valves were open at least .010 so i wasn't building compression.... i adjusted the valves and it started up IMMEDIATELY. i cannot explain the lack of spark though... thats just totally bizzare, cause it will run now.

but yeah I am back to where I was before, having no idea how to set the timing whatsoever. time to read some old threads.

[2oodoor]

**AHEM**

don't know why I wasn't getting spark before... but it turns out there was a whole lot of other stuff wrong, which has since been addressed, and now I need to fricken learn how to time this thing.

as for the solution that made the car run..... wellll....... i have changed that head out so many fucking times, i forgot that when i removed the head i was using a stock cam, but when I put it back together i was using a 282 cam. turns out the 282 has a bit higher lift, so all of my valves were open at least .010 so i wasn't building compression.... i adjusted the valves and it started up IMMEDIATELY. i cannot explain the lack of spark though... thats just totally bizzare, cause it will run now.

but yeah I am back to where I was before, having no idea how to set the timing whatsoever. time to read some old threads.

Yeah, he got it running!!!!
Keep it simple stupid!!
isnt that always how it is when your stumped.,, you come back later and BAM a revelation hits you , oh yeah I forgot to plug it in!!! this time it was a little deeper but all the same....
Just yanking your string Bobafett, I enjoyed the thread