360 timing ignition woes

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moparjoe71

moparjoe71

4speeder
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Central washington
i have a fairly built 360 that has been a great runner for the last ten years, last winter I tore the car down for a restoration but didn’t touch the engine. Some thing has changed while the engine was on the stand. It was very difficult to time and never felt as powerful as before the restoration. The engine ran great but didn’t feel like it was all there until about a month ago, that’s when it became hard to start I adjusted the timing and got it to start ok cold but then it wouldn’t run once it warmed up It would die at idle and I would have to retard the timing to get it to restart. I have replaced the ecu, coil, cap, rotor, plugs, wires, ballast, everything ignition wise I even replaced the distributor. It has gotten progressively worse and now when I crank it it won’t fire at all. All I get out of it is a back fire through the mufflers followed by a back fire through the carb. I’m at a loss. Any one have a suggestion for my next move?

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Yout first order of business should be to find true TDC. Get or make a piston stop and go from there. There are plenty of articles on here about how to do it. Once that's established, let us know what you find. It could be that the balancer outer ring has slipped. That's what you will be checking for when you find TDC.
 
If you’re backfiring through the carb - it may need to be inspected - especially a Holley. I agree - check for slipped timing first. Triple check the plug firing order and that the distributor cap is on correctly and the spark has an easy path. Ensure the polarity and gap of dist. pickup is correct - also check the coils polarity - positive is always 12v hot in crank/run - no interruptions. That the ecu is grounded properly and you have a nice strong battery or two.

Did you change all those parts because of this problem?
 
Since you had a restoration, you may have removed/moved all the wiring in the car, including the firewall connector and the connectors to the ignition switch. I'd get out the schematic (download fro MyMopar) and inspect all the connectors, and trace all of the wires involved in the ignition system, from battery through ignition switch, through the firewall connection, etc.

Make sure you have a good ground on the case of the ECU; if you don't want to scrape off new pain underneath the ECU case, then apply some star washers to complete a good ground there. Same applies to your grounds from battery to engine and to body. New paint can mess all that up.

This may not be the issue, but you don't want erratic electrical connections, and the restoration has some potential to cause that.
 
halifaxhops said:
Did you check the timing chain for stretch yet?
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As of yesterday day the true tops dead center is spot on with the balancer mark. All of the grounds for the engine, ecu, battery are good bare metal. I do have one exhaust lobe on if I remember correctly hole number 7 that wasn’t flat but wasn’t great either. As for checking for timing chain stretch the only method I’m aware of to check this is to rotate the engine back and forth while watching the rotor for play and that does not show any warning signs. Thanks everyone for the replies I am at a loss
 
Also to note on the wiring harness: I did upgrade the charging system to bypass the amp meter and upsized the charge wire to the battery from the alternater. And I pulled apart each side of the bull head and cleaned each connection and reassembled and upgraded to head light wording to the run through relays. Not sure if it helps. But the cam is a hydrolic 528 lift. 302 duration and the chain is a cloyes double roller
 
T56MaxTorq said:
If you’re backfiring through the carb - it may need to be inspected - especially a Holley. I agree - check for slipped timing first. Triple check the plug firing order and that the distributor cap is on correctly and the spark has an easy path. Ensure the polarity and gap of dist. pickup is correct - also check the coils polarity - positive is always 12v hot in crank/run - no interruptions. That the ecu is grounded properly and you have a nice strong battery or two.

Did you change all those parts because of this problem?
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All of the parts changes were an attemp to resolve the issue. The car ran fine a month ago it was just a little under powered from how it was before the resto
 
moparjoe71 said:
Also to note on the wiring harness: I did upgrade the charging system to bypass the amp meter and upsized the charge wire to the battery from the alternater. And I pulled apart each side of the bull head and cleaned each connection and reassembled and upgraded to head light wording to the run through relays. Not sure if it helps. But the cam is a hydrolic 528 lift. 302 duration and the chain is a cloyes double roller
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Very good on the connections. But something has changed and the good work you did on the electrical connections may have become undone. So don't rule out anything at this point. More thoughts:
  • Did you set the reluctor gap to the distributor pulse ring to .008" with a non-magnetic feeler gauge?
  • Have you checked the 2 prong connection between the distributor and the ECU to make sure the wires are not swapped? This will cause the ECU to trigger on the wrong edge of the magnetic impulse (the slow edge) and cause erratic timing.
  • Turn the engine to where the reluctor gap is aligned with one of the 'peaks' on the distributor ring (where it ought to fire a cylinder) and then look at exactly where the rotor is pointing It ought to be close to one of the spark towers. If it is in-between towers, then you have a rotor phasing issue.
  • Use a voltmeter to make sure the coil+ is getting 10-11 volts while cranking.
An electrical issue is the 1st thing to suspect... the slow cranking and the erratic firing and backfiring is symptoms of this.
 
First off thank you all for the suggestions I am very happy to say I have resolved my issue, but am ambarressed to say what I found lol. It turns out that my ecu was the problem the whole time, I replaced it and every other ignition/timing part all at once and some how managed to set my crank shaft to top dead center........on the exhaust stroke. Sooooo several sleepless nights and hours in the shop all I needed to do was spin my distributor 180 and all was fixed. What started as a simple parts swap turned into a much bigger ordeal due to me missing a simple step
 
moparjoe71 said:
That’s crazy that we live in the same town have you seen my car around? I have had it since 1998 and the car has been in selah since 1972? Do you have a car I would recognize?
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You might have seen my car. I haven't drive in it much since 09/30/2014 because things went sideways.
 
yellow rose said:
You might have seen my car. I haven't drive in it much since 09/30/2014 because things went sideways.
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Life has a strange way of doing that to us! I did a repaint and new power train in 2005, got married and had a couple of kids and didn’t so much as look at my car from 2008-2018. I walked into the garage one day and noticed a small rust bubble on the front fender and boom out of nowhere I am sack deep in a 100% tear down and restoration. I am sure glad I did it though I had forgotten how much I enjoy this hobby and I provided some great quality time for me and my son, so what kind of a body do you have?
 
moparjoe71 said:
Life has a strange way of doing that to us! I did a repaint and new power train in 2005, got married and had a couple of kids and didn’t so much as look at my car from 2008-2018. I walked into the garage one day and noticed a small rust bubble on the front fender and boom out of nowhere I am sack deep in a 100% tear down and restoration. I am sure glad I did it though I had forgotten how much I enjoy this hobby and I provided some great quality time for me and my son, so what kind of a body do you have?
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73 Dart Sport. Top Banana yellow with Raisin Bran hood.
 
yellow rose said:
73 Dart Sport. Top Banana yellow with Raisin Bran hood.
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I think I know your car. If you have the one I’m thinking of I saw it at 5he little league fields a few years ago. Manual transmission and super loud exhaust? Straight pipes or maybe even open headers? If so I parked next to you at the fields it has been at least 5-6 years
 
moparjoe71 said:
I think I know your car. If you have the one I’m thinking of I saw it at 5he little league fields a few years ago. Manual transmission and super loud exhaust? Straight pipes or maybe even open headers? If so I parked next to you at the fields it has been at least 5-6 years
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My. At wouldn’t have matched my avatar at all. It was triple black back then and was also super loud
 
moparjoe71 said:
As of yesterday day the true tops dead center is spot on with the balancer mark. All of the grounds for the engine, ecu, battery are good bare metal. I do have one exhaust lobe on if I remember correctly hole number 7 that wasn’t flat but wasn’t great either. As for checking for timing chain stretch the only method I’m aware of to check this is to rotate the engine back and forth while watching the rotor for play and that does not show any warning signs. Thanks everyone for the replies I am at a loss
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Help us out here. How did you go about checking TDC?
 
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