No spark at plugs?

Tiny
KORN13
  • MEMBER
  • 1995 CHEVROLET BLAZER
  • 4.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 195,000 MILES
My chevy blazer no start.I changed all. Sensores. And. Nothing. Whtas happen u need ur help I Live in México. Im sorry my inglish. Thank u ver y much
Friday, August 7th, 2015 AT 9:32 PM

54 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
It sounds like the pickup coil for the ignition is not working but we should run down this guide to help us see what's going on.

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Please run down this guide and report back.
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Saturday, August 8th, 2015 AT 4:45 AM
Tiny
KAROW1972
  • MEMBER
  • 3 POSTS
  • 1994 CHEVROLET BLAZER
Electrical problem
1994 Chevy Blazer 6 cyl Four Wheel Drive Automatic

i have a 1996 chevy blazer 4.3 v6 4wd.
I have spark to the distributer, but no spark out.
I replaced the ignition module(the old one did test bad, and the new one does test good)but still no spark.
I tested the pick up coil, and it tested fine.

Any body have any ideas?Please?
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Hello, if your saying, you took the coil wire loose from the cap, held close to engine ground, engine cranking, there was spark from the coil wire? It either the cap or rotor. Can't think of anything else? Maybe I misunderstood your post?
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
KAROW1972
  • MEMBER
  • 3 POSTS
Thats it, I get spark out of the coil, but no spark from distributor. Cap and rotor seem to be fine, worn, but fine.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
The cap and rotor are maintenance issues, if it has been awhile, replace them.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
JAYPRINCE79
  • MEMBER
  • 3 POSTS
  • 1993 CHEVROLET BLAZER
V-6, 4.3L. 192,000 miles. Ran great, started fine. New battery. Started, drove one block and died. Has not started since. No spark anywhere (plugs, ignition coil, distributor). Distributor rotor? Timing Chain? How do I troubleshoot beyond not getting spark?
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+1
Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
PEAR69
  • MECHANIC
  • 1,482 POSTS
This sounds like an ignition module. Take it off and have it tested. If it's bad replace it, but start there, do not go changing things until you comferm that they are bad. Autozone or a place similar will do this for free. Let me know how you make out.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
JAYPRINCE79
  • MEMBER
  • 3 POSTS
Thank you, going to do this tonight and will get back to you.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
JAYPRINCE79
  • MEMBER
  • 3 POSTS
So I took out the Ignition module, took it to Autozone, they tested, and it was dead as a door nail! $29.99 later the truck pur's like a kitten! THANK YOU!
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
DUREK420
  • MEMBER
  • 3 POSTS
  • 1993 CHEVROLET BLAZER
  • V8
  • 4WD
  • AUTOMATIC
  • 210,000 MILES
Hi been working on my 93 chevy blazer just quit on me have no sprak or fuel changed coil and pick up coil. Still will not start but if I leave it over night then try to start it next day it will start runs great then stalls. May start again but after it stalls out again nothing not spark or fuel. It does have auto start not sure if that has anything to do with i. Hope you can help thanks.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Possible Causes & Corrections: Ã Â Â Ensure hot air tube is connected to air cleaner. Ã Â Â Check thermostatic air cleaner for proper operation. Ã Â Â Check Idle Air Control (IAC) system for proper operation. Ã Â Â Check PCV valve for proper operation. Ã Â Â Unplug MAP sensor. ECM substitutes a default value for sensor signal. If stall condition is eliminated, replace sensor. Ã Â Â Check EGR system for proper operation. Ã Â Â If stall occurs when air conditioner is turned on, check for air conditioner clutch signal to ECM terminal. Voltage at A/C terminal of ECM should be battery voltage when air conditioner compressor clutch is engaged. A high voltage surge due to a shorted compressor clutch diode could cause ECM shutdown. Ã Â Â Check for an overcharged A/C system. Ã Â Â Check for plugged or restricted fuel lines. Ã Â Â If engine starts but then immediately stalls, open distributor by-pass circuit. If engine now starts and runs okay, replace distributor pick-up coil. Ã Â Â Using Spark Tester (ST-125), check for a weak spark from ignition coil.
Check crank sensor for signal when it wont start. Also was/is service engine soon light on? Read like this. Cross these two terminals as shown with a piec of wire, then turn the key on. Count the flashes, a 22 will flash as 2 flashes then a short pause, then 2 flashes, if more than one code is stored, the pause will be longer. The codes will display three times and end with 12. Write them down and post here. This connector is right under the middle of the dash...


https://www.2carpros.com/forum/automotive_pictures/62217_Pre95GM1_3.jpg

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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
DUREK420
  • MEMBER
  • 3 POSTS
The codes I got are 22 and 34 thanks for the help bro. Hope these are the reasons
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS


https://www.2carpros.com/forum/automotive_pictures/62217_22_1.jpg



https://www.2carpros.com/forum/automotive_pictures/62217_34_2.jpg


Try unplugging the MAF and see if it runs. Usually this is the TPS, replace that first. THROTTLE POSITION (TP) SENSOR 1. Install jumper wires to enable connection of a DVOM in parallel between TP sensor harness connectors. Connect DVOM positive lead to Dark Blue wire terminal. Connect negative lead to Black wire terminal. See Fig. 3 . 2. Turn ignition on, engine off. Signal voltage should gradually change from less than one volt at closed throttle to about 5.0 volts at wide open throttle position. If reading is not as specified, replace TP sensor. 3. TP sensor circuit malfunction should set a related trouble code. For further information, see appropriate TESTS W/CODES article in this section. Also see TPS ADJUSTMENT in ADJUSTMENTS article in this section.


https://www.2carpros.com/forum/automotive_pictures/62217_TPSGM_1.jpg


MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1. MAP sensor circuit malfunction should set a related code in ECM memory. See Fig. 1 . If a code is present, see appropriate TESTS W/CODES article in this section. An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. If driveability problems exist, MAP sensor failure is suspected and no MAP code is present, disconnect MAP sensor connector. If driveability condition improves, check MAP vacuum hose for splits, kinks, proper routing and blockage. If no problems are found, replace MAP sensor. 2. With ignition on and engine off, check MAP sensor parameter using a scan tester connected to Data Link Connector (DLC). Voltage should be as specified in MAP SENSOR VOLTAGE RANGE table. 3. If MAP sensor voltage is as specified, go to next step. If voltage is not as specified, check for 5-volt reference supplied to sensor. Check harness integrity. If no problems are evident, replace MAP sensor. 4. Using a hand-held vacuum pump, apply 10 in. Hg to MAP sensor and note voltage change. Voltage should drop to about 1.0-2.5 volts less than specified in table. If voltage is not as specified or voltage reading does not immediately follow vacuum change, MAP sensor is faulty.


https://www.2carpros.com/forum/automotive_pictures/62217_34a_1.jpg

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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
DUREK420
  • MEMBER
  • 3 POSTS
Those would make not have sprak anf fuel
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Not usually a spark, but could be a fuel problem. Did you check all fuses marked IGN? Under the hood fuse box? And what does the security light on the dash do 1.) Before you insert key? 2.)After you turn ignition to just ON position? And then crank?
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
TAZBONE
  • MEMBER
  • 1 POST
  • 1993 CHEVROLET BLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 11,200 MILES
Heres the big problem, Ive been working on cars for 28 years, ha ha. Just stumped, got this 4.3 in a blazer my son asked me to look at, not running and no spark, checked out all things, wires, coil, module, pickup coil, etc. Found that the housing around the pickup coil was broken, found good used dist. At salvage, motor was running it came out of I heard it myself. Put it in had spark, motor ran for3 min. Died no spark. Started checking wireing to coil, starter, dist, etc. Had used coil sitting around laid it on other one hooked up had spark, motor ran 30 sec. Died, no spark, Checked for codes but son removed all fuses to check out and that cleared them. I'm stumped is it the computor or what with the way this is happening im at a lose.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi tazbone, Welcome to 2carpros and TY for the donation

Jump start the coil from the battery if it continues to -check the ignition primary circuit and the ignition switch-both okay last place is the computer
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
DAN PHILLIP
  • MEMBER
  • 1 POST
  • 1992 CHEVROLET BLAZER
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 210,000 MILES
My vehicle is a K1500. Engine just cranks, no spark, tachometer does not move on dash panel. Fuel pump/sending unit/tank all replaced. Fuses all checked, relays all good. Ignition control module has been tested, and ignition coil replaced. Engine has only has 20,000 miles since full rebuild, and the spark plugs have been changed recently. Fuel pump primes when key is turned to on position, but engine just cranks.
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,004 POSTS
Has the distributor been taken out during this issue?

The Medic
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,004 POSTS
Also,

With the key 'on', What is the voltage to the positive side of the coil?

The Medic
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Wednesday, October 14th, 2020 AT 2:39 PM (Merged)

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