Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Engine (
-   -   blazer has spark at coil and gas no spark at plugs (

ricksautorestoration 02-09-2007 03:45 PM

blazer has spark at coil and gas no spark at plugs
My 96 blazer was hesitating around 60 mph and recently completely quit. New fuel pump in it i have spark at the coil but none at the plugs. I take it my problem is in the distributor from what i have read the module is a common problem with these? Is there any way to test this out before buying one? IS there anything else i should check? I called the dealer today they want over 200 for just the module does anyone know if there is a place that sells modules aftermarket? I think i can get a whole distributor for less trhan that on ebay. Thanks would really appreciate it if anyone has any suggestions.

DoubleVision 02-09-2007 03:55 PM

Just about anytime a module goes, most go to the local auto parts store and picks up a new one, it lasts about a month, so they go get another one, it lasts about a month, you see where this is going. Anyways, I would also suspect the module, and I would replace it with a GM unit. If you can score one that`s still good in a junk yard or get one on ebay cheaper take that route.

demonspeeder 02-09-2007 03:58 PM

blazer has spark at coil and gas no spark at plugs
Some parts places like Advance Auto can test the modules...if you happen to get one that's not an idiot but yeah they can be tested and it costs you only time and gas to get there.

wrenchheads 02-09-2007 04:02 PM

blazer has spark at coil and gas no spark at plugs
If you have spark at the coil then you module is fine. How did you test spark at the coil? If you pulled the coil wire off the distibutor and tested there your coil and module are good. if you don't have spark at any of the spark plug wires then either you have a bad set of wires or distibutor cap is corroded, however you will usually not loss spark at all cylinders with wires and distributor cap. the most likely cause of no spark to all the cylinders would be a bad rotor. the rotor will affect all cylinders the same either with poor spark or in your case no spark.

wrenchheads 02-09-2007 04:07 PM

blazer has spark coil gas no spark plugs
don't believe module testing at the store, if it is an intermittent problem the test may not catch it. modules can be affected by temp. and other things. most modules may start working after cooling down then quit again, and work when tested.

ricksautorestoration 02-09-2007 04:37 PM

I tested the coil by taking the coil wire off the distributor and grounding it on the part of the engine and there was a lot of spark then i hooked it back up to the coil and checked my plugs theres no spark there? Wouldent that tell me there is a problem at the distributor? I changed the rotor and the cap looks perfectly fine.

poncho62 02-09-2007 04:41 PM

Did the metal piece come out of the centre terminal of the cap?

The spark goes from the coil wire, into the cap, though the rotor and out the various terminals, through the wires to the has to be one of those things.

ricksautorestoration 02-09-2007 04:50 PM

Thanks poncho thats what i thought so if i have power in my coil wire but not at my plugs. The problem has to be somewhere in my distributor because its not getting to my plugs. My cap rotor and wires are all new i figure it must be the module. Thanks

35WINDOW 02-09-2007 04:53 PM

Stupid question-you said the Cap and Wires are new-did you just put them on? If you did, you sure they are in the proper locations?

ricksautorestoration 02-09-2007 04:55 PM

yes double checked the wires they are all in the right location.

poncho62 02-09-2007 05:01 PM

All the module does is switch the coil on and off....which it is doing. The problem is either your cap , rotor or wires.....can't be anything else. I think the button is missing out of the cap or the centre of the rotor is broken off, or not touching the button.

fast68 02-09-2007 05:01 PM

check the pink and white wires from the coil to the distrib they commonly break inside the insulation and you cant tell just by loooking, wiggle and move them around while someone cranks the engine,

ive had this problem before,

the new harness is 20 bucks

it cause no injection and no spark both,
took months to figure it out

replaced it and it has been great for three years now

we wasted our time with replacing the FP twice and other stuff when it was nothing but a stupid cheapo wire broken

ricksautorestoration 02-09-2007 05:07 PM

I will check the cap again i'm sure its ok and the rotor is brand new but i'll double check the cap again. I was wiggling those wires around from the coil to the distributor earlier and hoping but it dident help if i have to i will inspect these wires better.

wrenchheads 02-09-2007 05:10 PM

re: blazer has spark at coil and gas no spark at plugs
If you have spark at the coil then the problem is not the module. The module is what tells the coil to fire. I has to be the rotor or the cap, they are in a hard spot to install so double check they are in correctly and the cap is on tight. I have seen the top contact of the rotor get bent up away from the coil terminal inside the distributor cap cause no transfer of spark to the rotor. Your problem has to be the coil wire not puged in tight, incorrectly installed distributor cap or rotor, or by a long shot all of your spark plug wires are bad.

matt167 02-09-2007 05:10 PM

if your actully getting voltage out of the secondary windings of the coil, the fault would be within the coil wire, or the spark is grounding inside the distributor. if you have voltage to the coil, but no spark, take a test light, hook it up to the - side of the coil then ground it, if the light flashes, your getting a signal from the modual, if not, your not getting a signal. you could have the modual tested, if it's not flashing, if it's good check the hall effect/ Magnetic pickup to make shure it's working, a magnetic pickup will generate a voltage, if you spin the motor over, with a dvom hooked up, you can verify it's working by this. the modual is a transistor, when the magnetic pickup/ hall effect triggers, it turns off the voltage to the coil, the magnetic field collapses and induces a voltage into the secondary windings.

Also check the crank sensor, some ign's will not pulse until the modual get a crankshaft position ( MOPAR is big on this ). we just finished up a '95 Jeep that an autoshop was playing parts changer on, it would not start, he replaced hall effect sensor in the dizzy , starter, ASD relay, ignition switch and wanted to replace the PCM. after a little reserch on shopkey, I found that on this jeep, the ignition will not pulse without a crankshaft position, so we tested the crank sensor with a lab scope, and shure enough, it was bad, replaced and it runs good now.

All times are GMT -6. The time now is 12:42 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.