StupEd05

I have taken it off and cleaned it. IIRC the ground cable is not covered in plastic or anything, could the ground wire itself be bad and not just the connections?

Thanx a lot!

Phil Coomber

Yes - the ground wire could be bad - or it could be where the wire connects to the spade. Any auto parts store will have them cheap. In my opinion, it would be worth the $5 or so putting it on to see. I recommend the braided type as opposed to the covered wire type.

Or, alternatively, you could use an ohmmeter to check the resistance between the block and the negative terminal on your battery.

Phil

StupEd05

Any idea what the ohms between the block and neg lead should be? I have tried starting the car by placing a jumper cable between the block and the neg lead on the battery to sort of ground it. Not sure if that should have worked though.

Thanx!

Phil Coomber

I just went out and checked mine - it was 3 ohms between the negative terminal and the block. I would think that that would be a little high, though. Maybe it's time for me to clean my grounds, too.

Phil

StupEd05

Wow, Thanks for the fast reply! As soon my dad gets home with his multi-meter I will check mine.

I just went out and re-tested the spark, I put a spark plug in the coil wire and watched it while I was cranking. I noticed it looked very sporadic. Sometimes times not even sparking for a little bit. Then hooked it up to #4 plug wire and it looked as if it would spark great a couple times then go a couple with a very weak spark then get a few good ones again. What would cause it to be sporadic?

Phil Coomber

A crappy coil / bad engine ground / bad plug or coil wires. I may have a spare coil at home. I'll take a look tonight.

Phil

theedge

Im gonna go with AFM still or the coil. Maybe try cleaning the connectors to the coil? Or flat out replacing it, with say an MSD Blaster2. Or swap with someone to test. The coil would sit in the line of fire of that pulley flinging fluid...

StupEd05

I tried a MSD Blaster 2 a couple weeks ago. Didnt notice if it helped with it being sporadic or not. But it still didnt go. The only thing from the coil on I havent replaced is the rotor.

User 41221

Have you looked at the leads on the coil wire that runs back to the 12V power and ground?

Regards,

StupEd05

Yeah, i have traced just about every wire I can see! I get 11.2 volts at the coil. I also get 0.6 ohms between the frame/block and the neg lead on the battery. Phil - you sure yours is right? Hell mine is prolly wrong! Damn multi-meter, so many options!!

Im not so sure the sporadic spark means anything. I had the plug in the coil wire and with that connector it doesnt snap in very well so Im sure the connection couldnt have been great. Is there anyway to read volts getting to the plugs? Anything that can read that pulse? A tool such as this would be a HUGE help!

theedge

For the frame to the battery, the lower the resistance the better, but I dont know what it should be. I dont think the spark should be too sporadic especially if youve got the spark plug hooked straight to the coil? The charge/discharge cycles of capacitors are very predicatable in their nature, so if its sparking randomly, there may be other issues.

Tested the alternator voltage regulator? Cleaned the battery terminals really well? When you had the AFM open, did you retrack it?

And to test the coil, be careful. Even a poorly operating one should be able to pump out an easy 20,000 volts, I doubt your multimeter can read that. To test its pulse youd need an ocislscope, those can usually read some pretty wicked voltages.

StupEd05

hmm... alternator voltage regulator? Worth a check... Haven't retracked the AFM. Dont have an oscilliscope.

One more thought, the whole about it firing a couple times when I stop cranking (not all the time, but it does it a lot), could it be that there is not enough voltage getting to the coil when the starter is running? So as soon as the starter stops it sparks enough but then the DME stops sending the signal cause the car isnt running. anyway of checking this or if that is even possible?

StupEd05

I got it running for about 2 minutes earlier. RPM's were at 900-1000 but it didnt sound like it. Sounded pretty rough and random. Spraying some carb cleaner helped for about 5 seconds then it got just as bad again. And spraying more didnt help. Started to turn the throttle cam and it revved for about 2 seconds, heard loud sucking noise and bam, dead. Tried to start back up and no go. Pulled the spark plugs and they were very dark and a dry soot feeling to them. Im hopefully going to swap the AFM and DME onto Scotts tomorow evening to double check that those are good.

Any other ideas?? Preferably someone who has experienced this before?

Thanx.

Kevin Baker

Long shot here: Under the injection boot, on the block, near the upper balance shaft, there is a temperature sender that the DME uses to measure coolant(engine) temperature. It has a blue pigtail lead. IIRC it costs about $35. From what I remember it sends the engine temp to the DME so that it can adjust the air/fuel ratio properly for the operating condition.

Dave951M

Just a long shot here, but did you say that it smoothed out with carb cleaner? Could be a vacuum leak in ther causing the havoc.