Slant Six Forum :: Why the *#(@ did it just decide not to start?!

So does your '74 have a seat belt safety switch under the hood with a button on it? (usually a box on the driver's side fender, or other side if a dart)... did you disable the wiring harness connected to the underside of the seat (driver's side).... both of these items badly plagued the 1974 year until they 'redid' the system from late 74- early 1975...

Since the dealership never fixed the one in my aunt's 74 Valiant, we used to have to 'keep our butt' off the seat until the engine actually cranked and started, then we could put our seat belts on....

Time to get the manual out and check for the circuit then hunt it down and get rid of it before it 'cuts your ignition' in traffic....(don't ask how I know...)

good luck,

-D.Idiot

so I know the timing chain is still okay

Right now my bet is on just that: An ignition component that decided to die. It'll throw something of a spark for you out in the open, but under compression load, it doesn't have the poop. I would suspect the ignition box (ECU), the ignition coil, and the pickup coil in the distributor in that order.

Do definitely check for a slipped timing chain, but if you were getting any kind of a workable spark to the cylinders, I would expect some hiccuping or coughing, frontwards or backwards, depending on whether the cam timing had slipped or not. You say there's no indication of any firing at all, so that's got me thinking "no spark".

Wow, that's a thick business card!

Wonder if the card I used to use was abnormally thin...it's been a long time since I had occasion to set the air gap and didn't have the brass feeler gauge. 0.014" is too thick. What do you measure a double thickness of regular copy/printer/"typing" paper at?

Jopapa, I'm still infusing caffine here so hang with me. I have always carried a spare ballest resistor for all my MoPar elec ign rigs. Now I don't know if you have a basicly stock ign system but if you do thats where I'd start. I learned that trick 30 years ago, running fine, shuter down, come back latter(10 mins, 10 hrs) no start! Plug in a spare and away we go

I didn't measure any regular copy paper but I did measure a post-it note at between .003 and .004

Author:	Jopapa [ Thu Jul 12, 2007 5:56 pm ]
Post subject:	*Why the #(@ did it just decide not to start?!**
Okay, so this morning I drive the Duster around to warm up the engine so I can run Dan's cleaner "soup" through it while I'm doing the brakes. Not a single problem at all while driving it. I get to the shop, jack up the front end, drain the oil, change the filter, fill the crankcase with the soup and go to start it......nothing. The starter will turn the engine, but it won't ignite at all. I check for spark, got it. Check for fuel, got it. Check for compression, got it. I pull the valve cover so I can watch the rocker arms as it's being cranked, and they're working, so I know the timing chain is still okay. I also verified that it's getting spark on the compression stroke (like what happened last time I had everything apart), and that was correct. I gave it a shot of starting fluid down the carburetor, and no cylinders even ignited that. WTF is going on??? I never even touched the ignition or fuel systems, and all of a sudden it decides that it doesn't want to start. I even jacked up the back end just no the offchance that maybe the high angle might have had something to do with it. Nothing. Tomorrow I'm taking my HEI stuff in so that I can get that hooked up in case the box or the coil went out, but I figure if either one did, I wouldn't get any spark at all. Is there anything else that might've failed and not allow the engine to start?

Author:	DusterIdiot [ Thu Jul 12, 2007 8:59 pm ]
Post subject:	The shame of the 1974 year...
So does your '74 have a seat belt safety switch under the hood with a button on it? (usually a box on the driver's side fender, or other side if a dart)... did you disable the wiring harness connected to the underside of the seat (driver's side).... both of these items badly plagued the 1974 year until they 'redid' the system from late 74- early 1975... Since the dealership never fixed the one in my aunt's 74 Valiant, we used to have to 'keep our butt' off the seat until the engine actually cranked and started, then we could put our seat belts on.... Time to get the manual out and check for the circuit then hunt it down and get rid of it before it 'cuts your ignition' in traffic....(don't ask how I know...) good luck, -D.Idiot

Author:	Jopapa [ Thu Jul 12, 2007 9:03 pm ]
Post subject:	Re: The shame of the 1974 year...
Quote: So does your '74 have a seat belt safety switch under the hood with a button on it? (usually a box on the driver's side fender, or other side if a dart)... did you disable the wiring harness connected to the underside of the seat (driver's side).... both of these items badly plagued the 1974 year until they 'redid' the system from late 74- early 1975... Since the dealership never fixed the one in my aunt's 74 Valiant, we used to have to 'keep our butt' off the seat until the engine actually cranked and started, then we could put our seat belts on.... Time to get the manual out and check for the circuit then hunt it down and get rid of it before it 'cuts your ignition' in traffic....(don't ask how I know...) good luck, -D.Idiot Nope, no box. I think it was bypassed a long time ago, because the front seat has been disconnected for as long as the PO could remember.

Author:	SlantSixDan [ Thu Jul 12, 2007 9:20 pm ]
Post subject:
The seatbelt interlock's always a good thing to keep in mind on a '74, but it interlocks with the starter control circuit, so the engine wouldn't crank if the interlock system were acting up (as designed or otherwise). Very strange mystery you've got on your hands, Jopapa. I think the clues indicate you are not getting spark to the cylinders at the right time. We've both been through this; it's so easy to be triple-certain the timing's right and still have it be wrong. But that wouldn't explain why it just suddenly refused to start, so check for basic failures. Rotor turning when you crank the engine...? Coil wire leading the spark to the underside of the cap, rather than astray...?

Author:	DusterIdiot [ Thu Jul 12, 2007 9:22 pm ]
Post subject:	Rock the crank...
Quote: so I know the timing chain is still okay Is it a high miler timing chain? Did you pull your distributor cap, and roll the damper back and forth about 20 degrees? and see if the rotor turned back and forth with 'no' delay? (if it even 'hiccups' slightly, timing chain has stretched and may be out enough to give the EI some fits...) Was the spark weak, intermittant...? Pull your plugs and see if they are still in good shape? Color? Maybe the car's holding out for a rebuild... -D.Idiot p.s. if you run the 'soup' through how long before you post that all the seals now are leaking because you cleaned the eons of sediment and primordial out of the engine that is helping keep the oil 'in'....

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Why the *#(@ did it just decide not to start?! https://www.slantsix.org/forum/viewtopic.php?t=24026	Page 1 of 2

Author:	Jopapa [ Thu Jul 12, 2007 9:37 pm ]
Post subject:
Dan, the rotor turned with no hesitation. As soon as the crankshaft turned, the rotor would move. I'll try moving the dampner back and forth tomorrow to see if there's any slop in the timing chain. I wouldn't be surprised if it's the original chain. When I checked for spark, it was at the plug wires. I used a tester and the spark through that was constant, but pretty damn weak (inside a decently lit shop, I had to struggle to see the spark), but I had chalked that up ot it just being on a crummy ground and a huge gap inside the tester. DI, the plugs were only slightly fouled. Surprisingly clean when I pulled them. I tuned the carb shortly after installing the, so the mixture was pretty good. As for the soup, the closest it got to being run through the engine was the minor pumping it got while I was trying to start the thing So I went ahead and drained it, and I just left the drain plug off the oil pan when I left, so tomorrow I'll just fill it with oil and put a new filter on before continuing with the troubleshooting. Any chance the ignition box or coil just suddenly decided to take a crap completely?

Author:	SlantSixDan [ Thu Jul 12, 2007 9:54 pm ]
Post subject:
Right now my bet is on just that: An ignition component that decided to die. It'll throw something of a spark for you out in the open, but under compression load, it doesn't have the poop. I would suspect the ignition box (ECU), the ignition coil, and the pickup coil in the distributor in that order. Do definitely check for a slipped timing chain, but if you were getting any kind of a workable spark to the cylinders, I would expect some hiccuping or coughing, frontwards or backwards, depending on whether the cam timing had slipped or not. You say there's no indication of any firing at all, so that's got me thinking "no spark".

Author:	Jopapa [ Thu Jul 12, 2007 10:14 pm ]
Post subject:
Quote: Right now my bet is on just that: An ignition component that decided to die. It'll throw something of a spark for you out in the open, but under compression load, it doesn't have the poop. I would suspect the ignition box (ECU), the ignition coil, and the pickup coil in the distributor in that order. Do definitely check for a slipped timing chain, but if you were getting any kind of a workable spark to the cylinders, I would expect some hiccuping or coughing, frontwards or backwards, depending on whether the cam timing had slipped or not. You say there's no indication of any firing at all, so that's got me thinking "no spark". I sure hope you're right. Tomorrow I'll just do a functional installation of the HEI so I can get the car running (if it is in fact a bad ignition component), and work on prettying it up later. Is there any good way to test the distributor's pickup coil? I have an extra from when I got a NOS electronic distributor that I can swap in if the current one is bad. I can't just swap distributors though because the one I ordered, unbeknownst to me at the time, has no accomodation for a vacuum advance.

Author:	SlantSixDan [ Thu Jul 12, 2007 11:40 pm ]
Post subject:
There are pickup coil tests, but you will probably find it faster and easier just to swap it if you suspect it. The air gap needs to be set correctly between the pickup coil and the reluctor. 0.008" with a nonmagnetic(!) gauge. They sell brass ones for the task, but a business card will do the trick OK.

Author:	dakight [ Fri Jul 13, 2007 5:26 am ]
Post subject:
I just measured a business card at .014.

Author:	SlantSixDan [ Fri Jul 13, 2007 8:44 am ]
Post subject:
Wow, that's a thick business card! Wonder if the card I used to use was abnormally thin...it's been a long time since I had occasion to set the air gap and didn't have the brass feeler gauge. 0.014" is too thick. What do you measure a double thickness of regular copy/printer/"typing" paper at?

Author:	6shotvanner [ Fri Jul 13, 2007 8:45 am ]
Post subject:	*$@#&%!!!**
Jopapa, I'm still infusing caffine here so hang with me. I have always carried a spare ballest resistor for all my MoPar elec ign rigs. Now I don't know if you have a basicly stock ign system but if you do thats where I'd start. I learned that trick 30 years ago, running fine, shuter down, come back latter(10 mins, 10 hrs) no start! Plug in a spare and away we go

Author:	dakight [ Fri Jul 13, 2007 10:57 am ]
Post subject:
Quote: Wow, that's a thick business card! Wonder if the card I used to use was abnormally thin...it's been a long time since I had occasion to set the air gap and didn't have the brass feeler gauge. 0.014" is too thick. What do you measure a double thickness of regular copy/printer/"typing" paper at? I didn't measure any regular copy paper but I did measure a post-it note at between .003 and .004

Author:	SlantSixDan [ Fri Jul 13, 2007 11:29 am ]
Post subject:	*Re: $@#&%!!!**
Quote: Jopapa, I'm still infusing caffine here so hang with me. I have always carried a spare ballest resistor for all my MoPar elec ign rigs. Now I don't know if you have a basicly stock ign system but if you do thats where I'd start. I learned that trick 30 years ago, running fine, shuter down, come back latter(10 mins, 10 hrs) no start! Plug in a spare and away we go Dead ballast resistor symptom: Cranks and fires, but quits as soon as you let go of the ignition key. Remember, the ballast resistor is bypassed during cranking.

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