No Spark - 4.3L S10 Pickup

sounds liker high resistance ,poor ground or frayed wire somewhere

Thank you Jim and Jimmy. I think I've found the solution. It seems to be in the connector to the Ignition Control Module. The White wire w/black stripe from terminal D on the ICM to terminal C on the Coil shows enough continuity to light an led test light, but a test with a multi-meter shows a significant drop in voltage. I'm going to see if I can temporarily bypass it. If that works, I will get a new connector. Jim, one of the tests for the ignition switch is the same as for checking voltage at terminal A. I have >10v there. I'll let you know how it goes.

On the road again. It was a bad connector that caused me grief. I replaced the connector to the ICM, but still had a no-spark condition. So I started re-testing, which took me back to the coil. The coil tested fine, the problem still seemed to be with the coil driver wire (white w/black stripe). I pulled everything out of the conduit and could not find any visual signs of damage. I got (false) positive readings for continuity. There was just enough contact for that reading, however I still had significant voltage drop. I replaced the coil primary circuit connector, and I am a happy man again.

Question? How did you bypass the ICM? Is there anyway to bypass all these sensors?? Im beating my head against a wall with the dumn things.

Hi Brandie, I didn't bypass the ICM. I bypassed the connector by connecting the wires directly to the ICM terminals. That was how I knew it was the connector itself. I wired a new connector in, and it's been running fine for the past year and a half. I don't think you can bypass the sensors, as they all play a part in the proper functioning of the engine. I used the diagnostic flow-chart in the Haynes manual to systematically test each component, and continuity of each wire. It took a lot of time. Good luck.

Thanks for the tip, died on me going down highway did restart for short time enough to get home then died again. Tried changing fuel filter, pump checked out but not much to no spark from coil. Put new coil on with again no spark. Checked out this forum and went out wiggled white wire with black stripe and whoooom started right up. Bad connection right at the plug in on coil. About to go out and fix this thing. Only 202,000 miles on tis 1998 sonoma 4x4, just keeps going! Thanks for the tip!!!!!!

Yes got a 93 S10 I was driving down the street it stopped working I put a new fuel pump in it and you feel filter and still no start is there anybody out there that can help me

Yeah check your ICM in a connections to your ICM which is located to the left side of your motor if your face in it it's got a two connectors to of there's a coil you'll see and without that there will be no function to your fuel injector

If that doesn't do it for you check the cap and rotor and possibly the ignition switch and I guess go from there

Haeve chevrolet s10 whit e distubuter e cramshaf sensor

I have a 93 S10 4.3 Automatic 2wd, I was driving and it just died, before that the engine idled high then low then smoothed out. Could not hear fuel pump kicking on and had it towed home. Next day put a fuel pump in it and a fuel pump relay, cranked it up before I put bed back on it ran and idled fine. Put bed back on drove about 5 mile to my home since it was out my dads bolted tool box in and get in to start truck and it will not start, have fuel to Throttle body but not spraying through injectors and I have no spark on plugs or coil. I think I have it narrowed down to the ICM. I supplied 12v to purple wire on ICM and it activated injectors, checked ignition coil checks good. So I'm down to the ICM also checked pickup coil in distributor and it checks good. What does everyone else think I'm about out of options.

don't waste time and money.. on cap rotor,ICM.....just replace the whole distributor.....$120.00....you'll have less money and time and stress invested.... I have a 1995 s-10 4x4...4.3 L...tbi...had no spark at plugs ...and no gas at tbi....i had power going to ICM....but no spark.....took ICM to auto zone had them check and their machine showed that the part was good....checked price on new ICM...distributor cap ..rotor...those cost close to $90.00....checked price of NEW distributor ... $120.00 +taX.. DON,T THROW NEW PARTS AT A OLD WORN OUT DISTRIBUTOR.....

how do you test an icm?

ok, injectors at throttle body is working fine. still no spark. ohm test on old coil failed so I replaced. still no spark

I changed out my coil and the ignition igniter that set on the side of my ignition coil.

Testing the ignition control unit requires the use of a high impedance digital volt/ohm meter (DVOM) and an LED test light such as Tool No. VAG 1527. A standard analog voltmeter or a standard incandescent 12-volt test light will cause damage to the unit. The ignition control unit is tested using a logical step-by-step process by checking the input and output signals. If the VAG 1551, VAG 1552 or equivalent diagnostic equipment is available, the first step in control unit testing is to check the control unit's fault memory. If this equipment is available, follow the manufacturer's instructions on its use and fault memory interrogation. WARNING When using diagnostic test equipment, always make sure the ignition is switched off before connecting the equipment to the electrical circuits. NOTE When performing the following tests, the vehicle's battery must be fully charged. WARNING Never crank the engine or turn the ignition switch on with a high-tension spark plug wire or ignition coil wire disconnected. If a plug wire or ignition coil wire is disconnected, it should be grounded before the ignition is switched on or the engine cranked. Because control units rarely fail, make sure the failure is not do to one of the following, and repair/replace as necessary. The control unit has not been exposed to excessive heat The control unit has not been contaminated by fluids The control unit has not been exposed to excessive moisture The control unit has not been exposed to excessive vibration or impact The related input and output components meet the manufacturer's specifications. The vehicle's charging system is not overcharging. Symptoms include a dry battery and/or warped battery case

Again my 1998 Chevy S10 No fire was caused by what is called an ignition igniter which sit on the side of my coil bracket next to the coil. I hope this will help someone with the same problem.

I have a 2000 Chevy s10 when I'm driving my truck just dies and then it's hard to start back up does anyone have any ideal what might be causing it to do that

I have a 1995 s10 ZR2 4x4 with the 4.3 vortex engine.Im getting power to the coil but nothing coming out of it I have no spark.I have tried 3 different coils still the same thing.Can somebody help me

I have a 1994 Chevrolet s10 5 speed 4cil.i was driving fine no problem.all of sudden it started too jump.i push in the clutch.it's running fine but when i put it first or 2 nd if i can get it up too speed long enough for me too shift.when im in gear it has no compression.please any help is appreciated.

I have a problem maybe yall can help I have an 89 s10 I done a v8 swap on it and I've lost constant 12v to the body so I ran a different wire from the junction block straight to the positive terminal on the battery and I can start it but now I have hooked up an msd 6a I had bypassed the icm in the distributor but where is the normal constant 12v

ive had this problem with a few different blazers with vortec 4.3l and it ended up being the icm. it didnt have a good enough connection and a little dielectric greese fixed the problem. just remove icm and clean it then put new dielectric greese on it bolt it back on and fire that thing right up.

my 92 GMC Sonoma ran fine last time I drove it 30 days ago. Went out to start it and it would turn over but would not start. After reading the posts in this column I decided to check for spark...no spark...after seeing all the trouble you all went through I pulled the ICM took it to NAPA and they tested it for free. It was bad...put a new one in and fired right up. Thanks foe all your questions and answers. I could have spent many hours testing and many $'s throwing parts at it but this was the short and sweet solution.

I have a 05 Chevy Cobalt Sedan that needs ICM replaced. We bought the new ICM but it won’t start. The light turns on but it won’t crank up or nothing. Help please

This happened with my 89 4.3, and it just happened with my 95 vortex. When I made it home, I went online, and I couldn't believe some of the guesses. In my case, it was random, occasional, and after letting it cool, or poking around checking electrical values, it would restart until the next event. One member stated that he cleaned the dielectric grease on the module, put new grease down, and that restored the ground to the module, and it started. The purpose of the grease in this case is to transfer heat, to cool the module down, so it dosen't fry itself as it works. Dielectric grease is also used to prevent corrosion between electrical connections. In my case, it was a pickup problem. Chevy always had the best designed, easiest to service distributors made dating back to the 55 small block and the blue flame 6 cylinder. I digress. With this distributor, someone put a shield over the pickup at the bottom of the distributor. Then the supplier of that cover did not properly plate it for corrosion resistance. When I pulled the distributor and opened it up.... Damn! The magnetic pickup was covered in rust from you guessed it, the cover placed over it, which wiped out the magnetic field it was supposed to generate. The truck had about 150k on it, and I chose to replace the distributor because of upper shaft bushing wear which was my fault. I never serviced the upper bushing grease reservoir, and wear occurred. Another member suggested a bad connection at a distributor plug connection, and I am going to check that first, after I first try cranking it tomorrow when I recover it. I hope this points you in the right direction. The respondent that replied it was a cracked head was a hoot. P.S. the icm, the module, grounds thru the retainer hex head screws. They are lightly torgued, to an inch pound value, maybe 4? inch pounds, not much. Happy hunting, and good luck.

I have a 1997 S10, has the 4.3 vortec automatic 2wd. It’s getting no spark, cranks over fine but won’t fire up replaced the distributor cap and rotor button, took the coil wire off to see if it would shock my finger. Nope still don’t have spark. What could be the issue?