# 1996 1500 Chevy NO SPARK!!!



## D2ka4

Okay here is a little backround on the truck..
I have replaced the original vortec 5.7 With a Ramjet 350 Crate motor from GM. I have spent many hours under the hood of the truck and it was running great. 2 days ago it died and never started back up. So i replaced the fuel pump and the fuel pump relay to regain my loss of fuel. Still no fire. SO i have recently put a new Accel Distributor with new cap and rotor, new accel coil, accel wires, new AC Delco plugs, New ICM, New crank sensor, and still no fire!!
I get power from the conector to both coil and ICM, and i even get the pop from the coil powering up when u turn the key on, but still no spark when cranking comming from the coil. I have tested the coil and it ohms out perfect, and i have had the new ICM tested and it is good. I am stumped I have spent alot of money in 2 days and still have gotten no where. Any help would be great!
Thanks
Dan


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## Raylo

Does this thing have a crank position sensor?


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## D2ka4

Yes it does and i has been replaced. Ive dont all the tests to make sure it gets power and functions properly


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## octaneman

Hi D2kA4

Have the cam sensor tested, the cam sensor provides the computer the information of when to give the signal to spark at the coil(s). Re-check your distributor timing to see if it's pointing at number 1 cylinder when the piston at cylinder number 1 is at TDC. If everything checks out ok and still no spark, hook up a test light to the module signal wire (check your wiring diagram ) and then by cranking the engine check for the ignition module switching. With the test light hooked up, when you crank the engine the test light should flash confirming signal pathway, if no signal is present then the module is bad.




post back your findings.


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## D2ka4

Ok, the cam sensor has been tested, its good, The timing w/ distributor is right on, now when i hooked up a signal light to the modual wire(with out ICM hooked up) i get no pulse. I know the ICM is good its new, and i had it tested before i left orileys. so with no signal present does that mean bad ECM or o wire shorted out?


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## octaneman

No. The computer only controls the spark advance in the ignition system, and if there is a fault the ECM will register an engine code. The ignition control module has to be connected to do the test I mentioned in my previous post, it is the module that acts as a switch for signal return NOT by disconnecting the ICM harness and doing the test from the ignition key. With everything hooked up including your test light, the ignition key is turned in the on position (engine off) the test light should be off. It is only when you crank the engine you will see if the module will be switching on/off, (test light flashing) when the key is in the off position the test light should go on. If nothing is going through, then you will need to verify with DVOM if there is 12 volts ( on some models 11.56v +/-) going to the module. If the voltage is not present then you will need to do a continuity test on the wires. 


Note: It is equally important that you repeat the test on the negative side of the module to see if there is a bad ground. 


post back your findings.


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## D2ka4

Ok, I did the test as u said to in the 2nd post with everything hooked up. I dont get anything from the test light, but i do have power to the module. When i hook up my volt meter to the signal wire and the key gets turned on it shows 13v ac, and while cranking it jups to 17-18, dont know if that helps or not but i figured id include it. I ran the ICM up to orileys again and had them double check it and it passes. Im not getting anything from the computer as far as an engine code. I have EFI Live for the truck and it has helped me alot with the conversion from vortec to the ram jet.

PS. Ive checked both the grounds at the ecm and at the ICM


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## octaneman

To help you better we'll need a little more information on your truck:


1) What model is your truck is it a C1500 or K1500 ? 

2) Is the Ignition system HEI ? (High Energy Ignition) this means that all components like the coil, magnetic pick-up, and module are present inside the distributor. 

3) Is the ignition coil external with 4 pins ? 



The information you provide on the type of ignition system will help us narrow down where the problem is. For example: If the ignition module has 4 pins and is inside the distributor connected to a magnetic pick-up coil, we can provide information on how you can test a module and other ignition components to determine if it's bad, even though the place where you had it tested says its good.


So far from the information you provided in your test analysis is that there are no codes and the crank sensor is good, this just leaves the question of the ignition module and the coil. The ignition pulse should be there because you said the module has been tested and passed, IMHO the ignition module is not functioning because it is clearly not switching. Remember, the ignition module acts ONLY as a switch so it either works or it doesn't.


post back your findings.


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## D2ka4

It Is a K1500 and it is not hei... The ram-jet came with an HEI system but i had converted that to a Standered ignition system that works with all the vortec ignition componets. So i have the distribitor, which i have just replaced with an accel, a coil that i just replaced(accel) new crank sensor and a $130 ICM from orileys. The cam sensor is apart of the disritbutor on this aplication, built in. Is there a way to bypass the ICM temporarly to make the system operate to indeed prove it is my ICM with the problem? I get power to all these systems as said before. Grounds are all good. And the Wht/blk wire that connects the coil to the ICM ohms out, so it makes the connection.


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## octaneman

This changes everything, the entire diagnostic procedure has to be modified to the accel distributor system. If I understand correctly, the accel distributor system was a direct conversion from the original HEI system to the accel simply by inserting plugs from one distributor to another. So the accel distributor you installed is producing a dual signal one for the crank sensor, and the other the cam sensor, instead of a single signal that came from the original HEI. 


Since the distributor is producing both cam and crank signals, you cannot bypass anything because the computer needs the input from both sensors to tell it when the piston is at TDC (crank sensor) and the exact time when to fire the spark (cam sensor) at the proper cylinder. So now everything has to be focused on the computer and the distributor including it's signal pathways. I am also assuming that your distributor is equiped with an LED ... Is this correct ? If not is there a point gap ?

Note: Is the coil external ?



Please post back the readings you get from your meter on both cam and crank sensor voltages from ignition on ( engine off) to cranking the engine.



post back your findings.


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## D2ka4

The Accel Distributor is an OEM replacement for the distributor that was on the vortec. The coil is external and so is the ICM. There acutully both mounted on the same plate. I have not altered the votec ignition system in any way. I chose to use the vortec ignition system rather than the HEI that came with the motor, just to make things eiser. Now with that being said i did have to use a computer from an LS1 setup to work. It cam out of a 3500 Van. But i used EFI live to make all the changes and re wired the the whole setup. I have chased every wire to ensure that one hasn't come loose or become grounded out. As far as the disrtubitor, i dont see an LED light on it, so im not sure where that puts us. I will get the volt readings later this afternoon. I have alot to do this morning..
Thanks again for all this help so far


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## octaneman

No problem. 

I'm guessing that your coil is the external type, so in order to facillitate quick testing of other critical ignition components so nothing has to be repeated, here is the testing proceedure for your external coil with 4 pin connector with diagram attached.: 



Externally Mounted Ignition Coil (Sealed Module Connector
Distributor)
Remove coil connectors and secondary coil wire. In test "A",
use high ohmmeter scale. See Fig. 7. If continuity is present, replace
coil. In test "B", use low ohmmeter scale. Reading should be very low
or near zero. If not, replace coil. In test "C", use high ohmmeter
scale. If there is no continuity, replace coil.


Please post back the results of your ignition coil test.


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## D2ka4

Yes the coil is external.... I performed the tests as shown and everything checks out on the coil. Its looks good
Ok whats the next step.


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## octaneman

Ok, I made some inquiries and here is step-by-step trouble shooter procedure for a 5.7 L 350 vortec ignition system OBDII. 


1) Perform Power train On-Board (OBD) System Check

2) Check spark plug wires for open circuits, cracks or improper seating of terminals at the spark plugs, distributor and ignition coil before preceding with test. Check spark plug with J-26792 spark tester or equivalent while cranking.(If there is no spark on one wire, check a second wire.) A few sparks then nothing is considered no spark. If adequate spark is present, go to HARD START diagnosis. If adequate spark is not present, go to step 3).

3) Remove coil from distributor cap. Insert J-26792 spark tester into the coil wire and clamp the tester to ground. Crank engine. If adequate spark is present go to step 13). If adequate spark is not present go to step 4).

4) Measure coil wire resistance using a DVOM. The resistance should be approximately 1000/inch. If resistance is within specified value go to step 5) If resistance is not within specified value, go to step 32).

5) Disconnect ignition coil harness connector. Probe ignition coil connector C with a test lamp connected to battery positive terminal. Crank engine. If lamp is flashing while cranking engine go to step 7) If test lamp is not flashing while cranking engine, go to step 6).

6) Turn off ignition. Probe ignition coil harness terminal C with a test lamp connected to battery positive terminal. If test light is illuminated, go to step 28) if not, go to step 9)

7) Probe ignition coil harness connector terminal B with a test lamp connected to battery positive. If test test lamp is illuminates go to step 29) If not go to step 8).

8) Ignition On, engine Off. Measure terminal A with a DVOM connected to a ground. If DVOM measures above 10V, go to step 21) IF not go to step 18).

9) Turn Off ignition. Disconnect ignition control module harness connector. Check for an open circuit between ignition coil harness connector terminal C and ignition control module harness connector terminal D. If circuit is open, go to step 27) If circuit is not open go to next step.

10) Disconnect ignition control module harness connector. Ignition On, engine Off. Measure voltage on terminal A at ignition control module harness connector with DVOM connected to ground. If DVOM measures above 10V, go to next step, If not, go to step 19).

11) Probe ignition control module harness connector terminal C with a test lamp connected to battery positive terminal. If test lamp is illuminated, go to next step, If not go to step 23).

12) Disconnect ignition control module harness connector. Probe ignition control module harness connector terminal B with DVOM is set to AC scale connected to ground. Crank engine. Observe voltage while cranking engine. Voltage should be between 1-4VAC. If voltage is as specified go to step 20) IF voltage is not as specified go to step 15)

13) Remove distributor cap. Check caps for cracks, moisture, carbon tracts , or physical damage. If any of these conditions are present, go to step 34) If cap is ok go to next step.

14) Crank engine. Observe distributor rotor while engine is being cranked. If rotor did not turn, refer to appropriate Removal/Installation/ overhaul article. If rotor did turn, go to step 33).

15) Turn Off ignition. Disconnect VCM C3 connector. Check ignition timing signal circuit for an open between VCM C3 harness connector and ignition control module harness connector terminal B. If circuit is open go to step 24). If circuit is okay, go to next step.

16) Probe ignition control (IC) circuit at VCM C3 connector with a test lamp connected to battery positive terminal. If test lamp is illuminated, go to step 25) If not, go to next step.

17) Ignition On, engine Off. Probe ignition control (IC) circuit at VCM C3 connector with test lamp connected to ground. If test lamp is illuminated, go to step 26). If not, go to step 22).

18 Check for an open or shorted to ground ignition positive voltage circuit terminal A of ignition oil. Repair as necessary go to step 37).

19) Check for an open or shorted to ground ignition positive voltage circuit at terminal A of the ignition control module. Repair as necessary go to step 37).

20) Check for poor ignition control module connection. If problem was found go to step 30). If problem was not found go to step 35).

21) Check for poor coil connection. If problem was found go to step 30) If problem was not found, go to step 31).

22) Check for poor VCM connection. If problem was found go to step 30) If problem was not found, go to step 36).

23) Repair open ignition ignition control module ground circuit. Go to step 37).

24) Repair open IC circuit between VCM and ignition control module. Go to step 37).

25) Repair grounded IC circuit between VCM and ignition control module. Go to step 37).

26) Repair short to voltage in the IC circuit between the VCM and the ignition control module. Go to step 37).

27) Repair open in tachometer signal circuit between ignition coil and ignition control module. Go to step 37).

28) Repair short to ground in tachometer signal circuit between ignition coil and ignition control module. Go to step 37).

29) Repair short to ground in tachometer input circuit between ignition coil and instrument cluster. Go to step 37).

30) Repair circuit as necessary. Go to step 37).

31) Replace ignition coil. Refer to appropriate Removal/install/overhaul article. Goto step 37).

32) Replace coil wire. Go to step 37).

33) Replace distributor rotor. Go to step 37).

34) Replace distributor cap. Go to step 37).

35) Replace ignition control module. Refer to appropriate removal/Installation/Overhaul article. Go to step 37).

36) Replace VCM. Go to step 37).

37) Operate vehicle within conditions under which original symptom was noted. If system is not functioning properly repeat testing from step 1).



Please post back your results after going through the trouble shooter.


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## 97'sonoma

hmmm your distributer shaft could be 180 degrees off put no. 1 TDC and pull the shaft up slightly and turn it 1 slot at a time till its exact opposite from original spot. this is a common mistake because there is TDC for both intake and exhaust stroke and when first installing a distributer you're either 180 degrees off or dead on. and being 180 off wont trip any codes because every ting is working properly just your firing at the exact opposite time that you should be and a timing light will still show your timing to be exact.
just trying to help hope it works.


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## 97'sonoma

97'sonoma said:


> hmmm your distributer shaft could be 180 degrees off put no. 1 TDC and pull the shaft up slightly and turn it 1 slot at a time till its exact opposite from original spot. this is a common mistake because there is TDC for both intake and exhaust stroke and when first installing a distributer you're either 180 degrees off or dead on. and being 180 off wont trip any codes because every ting is working properly just your firing at the exact opposite time that you should be and a timing light will still show your timing to be exact.
> just trying to help hope it works.


note: this only works if you're geting fire to the plugs use a screw driver and shove it in the ind of a spark plug wire and hold it close to a piece of bare metal thats grounded. I dont mean to make either of us to seem like idiots but just incase this hasnt been done


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## D2ka4

97'sonoma said:


> hmmm your distributer shaft could be 180 degrees off put no. 1 TDC and pull the shaft up slightly and turn it 1 slot at a time till its exact opposite from original spot. this is a common mistake because there is TDC for both intake and exhaust stroke and when first installing a distributer you're either 180 degrees off or dead on. and being 180 off wont trip any codes because every ting is working properly just your firing at the exact opposite time that you should be and a timing light will still show your timing to be exact.
> just trying to help hope it works.


Its Dead on... Turst me Oct. Already went through this with me.. i made sure i was on the compresion stroke when i set the TDC and then set the distributor. Thanks though..
OCT. I still havent made it through all the steps you posted... The weather has been really cold and crappy... Im hoping tomarrow i can go through them
Thanks again


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## Baitbucket

I'm have this exact issue an are wonder if the culprit was ever found?


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## royce gibbs

Scanner reflect engine being cranked ? should see rpm w/cranking if crank sensor is ok.


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## Baitbucket

Thanks for replying. So I'm going to assume that his crankshaft position sensor was bad?!


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## royce gibbs

Negative, like you, donno what, if anything, fixed the prob. what I suggested was a good place to start in a "no spark" prob w/ob2 system. Did not see if that was ever done with original testing.


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## Baitbucket

Well I guess I'll keep hammering at it. Thanks.


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## royce gibbs

don't know what happened to the truck in posts...just saying scanning will tell you if ecm sees c.p.s. input....it will show cranking rpm...will show cam signal as 'yes' or 'no'
hope not too late to help.


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## Carlphelps04

I'm having a problem with my 1990 Chevy c1500. It started about two weeks ago. It stumbles on start up. The check engine light came on, and it said o2 sensor. I replaced that. It stopped for about 3 days and now it's back. It's even worse when I try to start the truck with the a/c turned on. If I sit there and give it gas it'll work it's way out in about 5 minutes. Can someone please help me with what to do. It's driving me crazy. And it's my company's truck so I need it running right. Idk what's going on with it.


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