Lost spark

[85 SQ]

85 Sierra with a 350 swapped my intake and carb deleted the smog . Got everything back together and now I have no spark . Brought #1 up to tdc made sure the rotor was pointed at #1 when I installed the distributor . I've double checked the firing order a couple of times I'm stumped as too why I suddenly have no spark . Any input is appreciated thanks

 

[85 SQ]

85 Sierra with a 350 swapped my intake and carb deleted the smog . Got everything back together and now I have no spark . Brought #1 up to tdc made sure the rotor was pointed at #1 when I installed the distributor . I've double checked the firing order a couple of times I'm stumped as too why I suddenly have no spark . Any input is appreciated thanks

I should mention I had no spark issues previously

 

[gotyourgoat]

Tdc on the compression stroke? Vacuum ports plugged if not in use?


Did you look everywhere even under the bed?
(Sorry could resist)

 

[HotRodPC]

And you're 100% positive you have all wires plugged into the distributor where they should go. Sometimes, people also end up plugging the IGN wire into the Tach side even though it shouldn't fit. Next thing I'd look for, is to make sure I didn't pinch a wire under the intake grounding it out causinga no spark situation.

And you are 100% certain it's no spark, and not no fuel?

 

[85 SQ]

And you're 100% positive you have all wires plugged into the distributor where they should go. Sometimes, people also end up plugging the IGN wire into the Tach side even though it shouldn't fit. Next thing I'd look for, is to make sure I didn't pinch a wire under the intake grounding it out causinga no spark situation.

And you are 100% certain it's no spark, and not no fuel?

Def no spark and I'm running a clear glass filter so I can see the fuel I'm also sure the wires are plugged in correctly and like you said the bat/ign wire won't plug into the tach side . I have not checked to make sure there's no a wire pinched under the intake it's doubtful bit worth a look . I checked the resistance between the tach and battery wire connects on the coil and it was less than 1 ohm test out at like 0.1
Which should be good . I think it's the original coil though it's got 7/16/85 burned into the top and it Def looks well used . I'm picking up an accel coil tmrw and see if that gets me anywhere thanks

 

[HotRodPC]

OK, I say it's doubtful you have a pinched wire if you know for a fact all wires are plugged in cuz I don't think they'd reach the dizzy cap of one was pinched between the block and intake.

So the next thing I'd check and have a feeling there's a chance that it's the dizzy rod to the oil pump. I'd pop the dizzy cap off and crank the engine to make sure the rotor is turning. Maybe it's not seated all the way or some other mishap and if the rotor doesn't turn it's going to give a fake no spark. Meaning, there's spark, it's just not being distributed to the plugs.

I know all this seems stupid, but since it was running fine BEFORE you took it apart, just going over all the basics FIRST.

 

[Matt69olds]

Do you have power on the pink wire with the key on? It should be plugged into the battery terminal of the cap. With the key on, you should have power on the tach terminal. Use a test right on the tach terminal, the light should flicker when you crank the engine. If not, either your pickup coil or ignition module died. Look closely at the wires for the pickup coil. The tend to break from the constant movement of the vacuum advance. Broken wires=no spark. You can have the ignition module tested at most parts stores. If you reinstall it, make sure you apply the heat transfer paste on the bottom of the module.

 

[1987 GMC Jimmy]

Yeah, if it’s not mechanical in nature or related to the work you did, I would say watch for that ignition module. Those things can leave you scratching your head sometimes.

 

[HotRodPC]

Yeah, if it’s not mechanical in nature or related to the work you did, I would say watch for that ignition module. Those things can leave you scratching your head sometimes.

Yes they can. You can even have spark sometimes and you'll get a no start. Not sure how that happens, but I've seen it a couple times. Either weak spark or what I think it probably is, wrong spark timing. The ESC models, the timing is retarded and allowed to advance within the module.

And here I always thought there was a monkey under the hood turning the dizzy when he heard a ping. The same monkey that sets the choke and turns it off. He's one busy dude during a cold start.

 

[CoggedBelt75]

Lots of people think since it doesn’t start they aren’t getting spark. So...I have to ask, what makes say you haven’t any spark? Did you pull the coil wire from the distributor and place it by a ground to see if it sent a spark when cranking it over? That would eliminate the coil. Or then pulled a wire from the plug and with a metal something in it, lay it by a ground and see if a spark jumps to ground and if it does, if the intensity of the spark was strong?

 

[85 SQ]

Lots of people think since it doesn’t start they aren’t getting spark. So...I have to ask, what makes say you haven’t any spark? Did you pull the coil wire from the distributor and place it by a ground to see if it sent a spark when cranking it over? That would eliminate the coil. Or then pulled a wire from the plug and with a metal something in it, lay it by a ground and see if a spark jumps to ground and if it does, if the intensity of the spark was strong?

It's an hei dist so no coil wire and least not a standard type . I pulled the # 1 plug and cranked it over while I held it against the exhaust manifold and a couple different bolts with the wire attached not even a flicker . Thanks for your input

 

[85 SQ]

Do you have power on the pink wire with the key on? It should be plugged into the battery terminal of the cap. With the key on, you should have power on the tach terminal. Use a test right on the tach terminal, the light should flicker when you crank the engine. If not, either your pickup coil or ignition module died. Look closely at the wires for the pickup coil. The tend to break from the constant movement of the vacuum advance. Broken wires=no spark. You can have the ignition module tested at most parts stores. If you reinstall it, make sure you apply the heat transfer paste on the bottom of the module.

I will test that wire for power later today thanks for the info

 

[85 SQ]

Thanks for all the input it's appreciated you guys have definitely given some things to go on

 

[Colin]

OK, I say it's doubtful you have a pinched wire if you know for a fact all wires are plugged in cuz I don't think they'd reach the dizzy cap of one was pinched between the block and intake.

So the next thing I'd check and have a feeling there's a chance that it's the dizzy rod to the oil pump. I'd pop the dizzy cap off and crank the engine to make sure the rotor is turning. Maybe it's not seated all the way or some other mishap and if the rotor doesn't turn it's going to give a fake no spark. Meaning, there's spark, it's just not being distributed to the plugs.

I know all this seems stupid, but since it was running fine BEFORE you took it apart, just going over all the basics FIRST.

Is the rotor turning while cranking?
You haven't said what manifold you replaced the original with?
Make sure distributor boss is the same height as the one you took off.

 

[78C10BigTen]

Yes they can. You can even have spark sometimes and you'll get a no start. Not sure how that happens, but I've seen it a couple times. Either weak spark or what I think it probably is, wrong spark timing. The ESC models, the timing is retarded and allowed to advance within the module.

And here I always thought there was a monkey under the hood turning the dizzy when he heard a ping. The same monkey that sets the choke and turns it off. He's one busy dude during a cold start.

Sometimes even flyin down the interstate at about 80 in the passing lane they just decide bye bye im out and the vehicle dies right there.... ask how i know lol