How to diagnose Bad Distributor
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Car: 91 Z28 Vert
Engine: 305
Transmission: TKO
Axle/Gears: 3.55 10-bolt
How to diagnose Bad Distributor
How do I go about checkign to see if my distributor is bad? OVer the last little bit the car would pull a no-start after short trips, and then re-start after sitting for a couple of hours, but yesterday it died again and I cannot get it re-started.
I seriously doubt it is fuel related since I cant even get it to run using quick start, and I also changed the Cap and coil with "good" ones and that did not change anything. I checked for a spark at the end of each of the sparkplug wires and yes there is a spark (sort of Orange in colour I might add). I am thinking that possibly the spark is not "hot" enough to get things going, and it might be a result of a bad distributor, but does anyone have any ideas or suggestions as to a) what it might be, or b) how to test for a bad distributor. Oh ya btw this is not on my Camaro but my winter beater, a 85 olds delta 88, 307, Carb.
Thanks,
I seriously doubt it is fuel related since I cant even get it to run using quick start, and I also changed the Cap and coil with "good" ones and that did not change anything. I checked for a spark at the end of each of the sparkplug wires and yes there is a spark (sort of Orange in colour I might add). I am thinking that possibly the spark is not "hot" enough to get things going, and it might be a result of a bad distributor, but does anyone have any ideas or suggestions as to a) what it might be, or b) how to test for a bad distributor. Oh ya btw this is not on my Camaro but my winter beater, a 85 olds delta 88, 307, Carb.
Thanks,
#2
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Try a rotor. If you haven't replaced it lately, you need one anyway, even if that's not your no-start.
If it still has trouble starting, it probably needs a module. Make sire when you replace it that you use the heat sink grease between the mosule and the dist housing.
If it still has trouble starting, it probably needs a module. Make sire when you replace it that you use the heat sink grease between the mosule and the dist housing.
#3
I agree, you can check the rotor just by looking at it to see how burnt up it is. As for the module, you can have them checked at any parts store. It sounds like the module is your problem.
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Car: 91 Z28 Vert
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I am going to look into that module, I am assuming, given the car etc, that it is something which is probably something which is relatively inexpensive, so probably worth while replacing even if it isnt gone.
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Car: 1991 RS
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dont discount the fuel pump, Mine was the same way, it would die, then I wouldnt be able to start it again, until it cooled down, no matter what I did. Replaced the fuel pump and havnt had a problem since.
just a thought.
just a thought.
#6
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BTW....what does the Module do???? And if that was gone would it still crank over? I wouldnt think it would crank if that was the problem, but then again I dont really know what the module controls etc.
#7
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The module is the thing that actually passes and then interrupts the curent through the coil, just like points used to do. It sees pulses from the pickup coil, and amplifies them to high enough power to make sparks.
Teh ignition module has nothing whatsoever to do with cranking. The car will crank just fine without it even installed; it just won't start.
Try a rotor first. That's the reason for about 90% of all ignition failures in that type of ignition system. I used to carry one around with me all the time, and got to meet a couple of pretty girls who were stranded by their cars that had stopped working, which I could revive in seconds with my spare. If that doesn't do it, change the module, which is inside the dist under the rotor. That's the reason for about 90% of the remaining failures.
Teh ignition module has nothing whatsoever to do with cranking. The car will crank just fine without it even installed; it just won't start.
Try a rotor first. That's the reason for about 90% of all ignition failures in that type of ignition system. I used to carry one around with me all the time, and got to meet a couple of pretty girls who were stranded by their cars that had stopped working, which I could revive in seconds with my spare. If that doesn't do it, change the module, which is inside the dist under the rotor. That's the reason for about 90% of the remaining failures.
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
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Axle/Gears: Ford 9"/31 spline spool/4.86
I had to diagnose a hard start/run rough fault on a late 90's GM truck with a 454. After blowing the muffler off it from a backfire I traced the problem down to a bad distributor. It was one of those plastic body style. The top internal bushing was completely worn out. The shaft moved back and forth and caused intermittant spark. Since this style of distributor was not rebuildable I had to order a new one. Worked fine after that.
If it won't fire even on starting fluid then it's definitly an ignition problem. There could be other mechanical problems. Maybe the timing chain has stretched or jumped a tooth. The distributor drive gear at the bottom is held on with a roll pin/spring pin.
I've seen the pin break and the drive gear spins. Since you're getting spark we know it's still rotating. Pull the distributor cap off and pull #1 spark plug out. Bump the engine over until #1 is at TDC or very close to it (check the timing marks). Look to see where the rotor is pointing. If it's not pointing at the #1 plug wire then the drive gear is probably misaligned. The distributor will need to be pulled to be fixed.
If it won't fire even on starting fluid then it's definitly an ignition problem. There could be other mechanical problems. Maybe the timing chain has stretched or jumped a tooth. The distributor drive gear at the bottom is held on with a roll pin/spring pin.
I've seen the pin break and the drive gear spins. Since you're getting spark we know it's still rotating. Pull the distributor cap off and pull #1 spark plug out. Bump the engine over until #1 is at TDC or very close to it (check the timing marks). Look to see where the rotor is pointing. If it's not pointing at the #1 plug wire then the drive gear is probably misaligned. The distributor will need to be pulled to be fixed.
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Car: 91 Z28 Vert
Engine: 305
Transmission: TKO
Axle/Gears: 3.55 10-bolt
Stephen....
Thanks for the suggestion on checking to see if the drive gear is spinning....I have put that down on my list of things to check, my only problem is that the car is waiting to be towed home by my buddy who said "oh sometime today or tomorrow I will be in your area to drop it off", so we will soon see, this problem has really ticked me off.
Thanks
Thanks for the suggestion on checking to see if the drive gear is spinning....I have put that down on my list of things to check, my only problem is that the car is waiting to be towed home by my buddy who said "oh sometime today or tomorrow I will be in your area to drop it off", so we will soon see, this problem has really ticked me off.
Thanks
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Car: 1986 Firebird
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If when you get it home, it starts right up, I'd definately be thinking ignition module; common failure goes something like this: Car is cold, means module is cold, so car runs great. Car heats up, module heats up, module fails, you get stuck on the side of the road. Car cools down, module cools down, car runs great. Over & Over again! The fact that the car would restart after sitting for a few hours seems to say it's the module.
If you change it, go to Radio Shack and buy some of their heat-sink grease. It's a white grease, costs you about $3 for a tiny little tube, but it's the good stuff, and the key point is, you'll have extra grease. Sometimes you can run thin with those little packets they include with a new module.
If you change it, go to Radio Shack and buy some of their heat-sink grease. It's a white grease, costs you about $3 for a tiny little tube, but it's the good stuff, and the key point is, you'll have extra grease. Sometimes you can run thin with those little packets they include with a new module.
#12
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Car: 91 Z28 Vert
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Thanks....I have still yet to check on things with it...I got it towed back today and there is no way I am going to spend my new-years eve working on that thing! It still does not start, but the more I chat with people on here, the more it seems to point towards the module, I am going to give it a shot tomorrow, hopefully things work out with it....I will keep you guys posted.
dave
dave
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Car: 91 Z28 Vert
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Go figure....I go out and give the Beast one last try at starting yesterday and it fires up after not starting for like 3 days and getting it towed home from Home Depot
Anyways, I pulled/replaced the plugs, wires, cap, rotor and module this evening. The plugs were NASTY, but I think I might have caught my problem. I think it might have been a combination of the nasty plugs and a Module on its way out, we will see how things are in the next coupel of days etc to see if the problem re-surfaces, if it does, I think I am going to take a hammer to that thing....Regardless thanks for your help guys
Anyways, I pulled/replaced the plugs, wires, cap, rotor and module this evening. The plugs were NASTY, but I think I might have caught my problem. I think it might have been a combination of the nasty plugs and a Module on its way out, we will see how things are in the next coupel of days etc to see if the problem re-surfaces, if it does, I think I am going to take a hammer to that thing....Regardless thanks for your help guys
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Re: How to diagnose Bad Distributor
Wow is this one from the past! I vaguely remember this issue with my delta..what the end fix was I cant recall but think it may have been the module....man I miss that pimp machine!
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