I need help brainstorming crank no start
#83
02-23-2020, 09:12 AM
yeah I had the same feeling aswell as all the guys helping me here and I have redone the distributer like 6 times. I ve followed the procedure from many articles and videos and have replaced this diatributrr before with success in the paat about 34 years ago. The reason I replaced this distrubuter again was because it had play and when I removed it the gear was all shewed up. I did buy a cheap distrbuter from walmart online so I'm starting to feel (althought I took a really good look at it compared to my original and looks exact) that it may be faulty and will be buying a new AC delco one.
#84
02-23-2020, 10:41 AM
You may have more than one thing going on but if you have verified proper fuel pressure and leakdown then ignition is almost certainly a feature of this problem. Some injector issues beyond proper pressure and leakdown should not be preventing the truck from starting.
It it sounds like you have a reliable coil spark pattern but perhaps not proper strength. If true that tells me that you probably have either a bad coil or marginal coil power or ground. Since you have replaced the coil this is not likely a coil issue. Does the original coil produce the same result? You have checked coil voltage and ground but the best test is net voltage under a load. We can into that when your ready. Because the spark pattern at the coil is reliable the ICM is probably ok because all it does is collapse the coil field in the primary to cause the amplified ignition voltage in the coil. It’s a series of 12v pulses. It is possible for those pulses to be inadequate so when your ready we can check the ICM power, ground and output.
do you get all the same problems with the original distr?
the PCM can also damaged but that is probably the least likely issue.
i don’t know if your coil output is marginal enough to prevent it from overcoming the wire resistance and distr gap but an open air gap test at the plugs does not require much energy, especially with a small gap. Because of that it still looks like you may have a distr problem or a timing problem. Because the truck died suddenly with an Undisturbed distr something else was wrong besides distr orientation unless the gear was worn enough to jump some teeth. That said, possibilities here are that you off by a tooth or more. If so experimenting either way may be in order. If this is part of the issue maybe your balancer and marks have slipped. I’ve never dealt with that so maybe Les can help us here.
Another possibility is a jumped timing chain but you did did that test that showed minimal chain looseness but I suppose that this is still possible. If the chain were way off though you would have crashed some valves and locked up the engine.
An injector problem is still still possible but you should concentrate on spark for now if you’ve done the fuel pressure sticky tests.
George
It it sounds like you have a reliable coil spark pattern but perhaps not proper strength. If true that tells me that you probably have either a bad coil or marginal coil power or ground. Since you have replaced the coil this is not likely a coil issue. Does the original coil produce the same result? You have checked coil voltage and ground but the best test is net voltage under a load. We can into that when your ready. Because the spark pattern at the coil is reliable the ICM is probably ok because all it does is collapse the coil field in the primary to cause the amplified ignition voltage in the coil. It’s a series of 12v pulses. It is possible for those pulses to be inadequate so when your ready we can check the ICM power, ground and output.
do you get all the same problems with the original distr?
the PCM can also damaged but that is probably the least likely issue.
i don’t know if your coil output is marginal enough to prevent it from overcoming the wire resistance and distr gap but an open air gap test at the plugs does not require much energy, especially with a small gap. Because of that it still looks like you may have a distr problem or a timing problem. Because the truck died suddenly with an Undisturbed distr something else was wrong besides distr orientation unless the gear was worn enough to jump some teeth. That said, possibilities here are that you off by a tooth or more. If so experimenting either way may be in order. If this is part of the issue maybe your balancer and marks have slipped. I’ve never dealt with that so maybe Les can help us here.
Another possibility is a jumped timing chain but you did did that test that showed minimal chain looseness but I suppose that this is still possible. If the chain were way off though you would have crashed some valves and locked up the engine.
An injector problem is still still possible but you should concentrate on spark for now if you’ve done the fuel pressure sticky tests.
George
#85
02-23-2020, 08:10 PM
You might want to try setting the distributor 1 tooth and even two teeth clockwise from the cast 6 (there are 13 teeth on distributor gear). If your outer balancer ring has started to slip on the rubber portion, doing this will potentially advance the distributor 27.7 distributor degrees (1 tooth) or 55.4 distributor degrees (2 teeth) and hopefully correct the rotor position. This is what TAJohns34 (under Tom Masticola's post above) apparently experienced. Now we're getting into the odd stuff. I think it's time.
I think you already did the prime with gas into the throttle body..... so security system shouldn't be an issue.
The weird thing is the one spark and then nothing at the spark plug. I suppose this could possibly be the issue with the spark choosing to jump to another terminal.
I think you already did the prime with gas into the throttle body..... so security system shouldn't be an issue.
The weird thing is the one spark and then nothing at the spark plug. I suppose this could possibly be the issue with the spark choosing to jump to another terminal.
Last edited by LesMyer; 02-23-2020 at 08:12 PM.
#86
02-24-2020, 11:15 PM
You may have more than one thing going on but if you have verified proper fuel pressure and leakdown then ignition is almost certainly a feature of this problem. Some injector issues beyond proper pressure and leakdown should not be preventing the truck from starting.
It it sounds like you have a reliable coil spark pattern but perhaps not proper strength. If true that tells me that you probably have either a bad coil or marginal coil power or ground. Since you have replaced the coil this is not likely a coil issue. Does the original coil produce the same result? You have checked coil voltage and ground but the best test is net voltage under a load. We can into that when your ready. Because the spark pattern at the coil is reliable the ICM is probably ok because all it does is collapse the coil field in the primary to cause the amplified ignition voltage in the coil. It’s a series of 12v pulses. It is possible for those pulses to be inadequate so when your ready we can check the ICM power, ground and output.
do you get all the same problems with the original distr?
the PCM can also damaged but that is probably the least likely issue.
i don’t know if your coil output is marginal enough to prevent it from overcoming the wire resistance and distr gap but an open air gap test at the plugs does not require much energy, especially with a small gap. Because of that it still looks like you may have a distr problem or a timing problem. Because the truck died suddenly with an Undisturbed distr something else was wrong besides distr orientation unless the gear was worn enough to jump some teeth. That said, possibilities here are that you off by a tooth or more. If so experimenting either way may be in order. If this is part of the issue maybe your balancer and marks have slipped. I’ve never dealt with that so maybe Les can help us here.
Another possibility is a jumped timing chain but you did did that test that showed minimal chain looseness but I suppose that this is still possible. If the chain were way off though you would have crashed some valves and locked up the engine.
An injector problem is still still possible but you should concentrate on spark for now if you’ve done the fuel pressure sticky tests.
George
It it sounds like you have a reliable coil spark pattern but perhaps not proper strength. If true that tells me that you probably have either a bad coil or marginal coil power or ground. Since you have replaced the coil this is not likely a coil issue. Does the original coil produce the same result? You have checked coil voltage and ground but the best test is net voltage under a load. We can into that when your ready. Because the spark pattern at the coil is reliable the ICM is probably ok because all it does is collapse the coil field in the primary to cause the amplified ignition voltage in the coil. It’s a series of 12v pulses. It is possible for those pulses to be inadequate so when your ready we can check the ICM power, ground and output.
do you get all the same problems with the original distr?
the PCM can also damaged but that is probably the least likely issue.
i don’t know if your coil output is marginal enough to prevent it from overcoming the wire resistance and distr gap but an open air gap test at the plugs does not require much energy, especially with a small gap. Because of that it still looks like you may have a distr problem or a timing problem. Because the truck died suddenly with an Undisturbed distr something else was wrong besides distr orientation unless the gear was worn enough to jump some teeth. That said, possibilities here are that you off by a tooth or more. If so experimenting either way may be in order. If this is part of the issue maybe your balancer and marks have slipped. I’ve never dealt with that so maybe Les can help us here.
Another possibility is a jumped timing chain but you did did that test that showed minimal chain looseness but I suppose that this is still possible. If the chain were way off though you would have crashed some valves and locked up the engine.
An injector problem is still still possible but you should concentrate on spark for now if you’ve done the fuel pressure sticky tests.
George
I really appreciate you guys sticking around I've replaced quite a few engines and been wrenching weekends on all my cars but never had this much trouble figuring something out and no where close to a mechanic just parts swaper lol.
I really am anxious to continue testing but haven't had time to replace the starter again. I actually seen a video where somebody's balancer slipped so his wouldn't line up and wonder if les may be right so as soon as I get the starter I will try the one tooth forward and back. And also will be getting a better spark tester the on im using at the plugs is just a light that glows when connected in series with the plug but it doesn't show me ark color or distance(for power) I read if its to low compression would not let it egnite.
Please stand by till i get the starter and get back to you guys with my results 😁
thank again
#88
02-26-2020, 04:14 PM
You might want to try setting the distributor 1 tooth and even two teeth clockwise from the cast 6 (there are 13 teeth on distributor gear). If your outer balancer ring has started to slip on the rubber portion, doing this will potentially advance the distributor 27.7 distributor degrees (1 tooth) or 55.4 distributor degrees (2 teeth) and hopefully correct the rotor position. This is what TAJohns34 (under Tom Masticola's post above) apparently experienced. Now we're getting into the odd stuff. I think it's time.
I think you already did the prime with gas into the throttle body..... so security system shouldn't be an issue.
The weird thing is the one spark and then nothing at the spark plug. I suppose this could possibly be the issue with the spark choosing to jump to another terminal.
I think you already did the prime with gas into the throttle body..... so security system shouldn't be an issue.
The weird thing is the one spark and then nothing at the spark plug. I suppose this could possibly be the issue with the spark choosing to jump to another terminal.
When I get a chance i will do the test your proposing with jumping abtooth forward or 2 forard and backwards from the 6. I just tried it again still don't have my ark spark tester its on its way but im using the one I showed here with it lighting up when theres spark and only spark one or two times then crank ,crank and I don't see it light up.I remove again the coil wire and I see the orange consistent spark about 1/2 jump non stop. Coil is new havent touched the ICM.
I also tested the power to the coil and traced it to the fuse block and tested it on the on position (i get 12v) and while cranking( I get 11v) I did look it up and it suppose to have 12v so I jumpered from a solid 12v to that fuse and no change still no consistent spark at the #1 just sometimes a small blink.
#89
02-26-2020, 04:26 PM
I have a quick question I want to rule out my cables (which are new) and was wondering if I put the rotor aiming at the #1 piston and with out crancking just toggles the data on the ICM to make it spark that way it stays at #1 would this be a good test that aleast my path from coil to plug is ok?
Another question so when I don't have someone to crank for me.... can I leave the key in the ON position and crank by jumping the starter relay? I've been doing it like this and it works but want to make sure I'm not over looking something.
Another question so when I don't have someone to crank for me.... can I leave the key in the ON position and crank by jumping the starter relay? I've been doing it like this and it works but want to make sure I'm not over looking something.
