Hello, I am a first time user of this sight so please forgive me if I am using the wrong forum. I bought the Blazer with a bad knock but the engine did run. I put in a new engine 4.3 and now it turns over and cranks but has no fire out of the coil. I am not very good with electrical so please be specific. I have put in a new cap, rotor, coil, and crank sensor. I verified the distributor was in correctly at the number six mark on the distributor which is at the #1 firing point. The wiring which goes into the ignition module- pink fuse output has power as does the wht/blk ignition coil driver. The two small wires which come out of the coil have power but there is no spark coiming out of the coil tower. I am at a loss. Please Help! Also does anyone have a schematic for the ignition system. Thanks

 

Walk through the steps in 98+ No-Start - Engine Cranks OK and if you still have the problem, report back in this thread.

 

Sorry, it took me so long to reply it has been a busy week and I spent all day yesterday in he garage with a budy from work trying to figure out this Blazer. Still has no spark I have went threw all 30 some steps twice and nothing. The small wire going to the coil has power but does not have a break in the power. Does the security system in the Blazer shut off fuel to the truck or just power? I am at a loss again any ideas would be appreciated. I also put a new ignition swith in the thing and nothing.

 

Just so everyone knows still in the garage with no spark. Newest part is a new computer which has been flashed for the blazer. I also put in a new ditributor. I have checked the wires in the wiring harness and still cannot get the blazer to start. I am ready to part the thing out. It is a nice Blazer and I hate to see it end like this but I am at a loss and do not know what to try next.

 

i may be wrong but did you make sure to install the ground strap to the rear of the passenger side head, i think the coil uses the engine for a ground supply through the mounting bolts and bracket, hope this helps if i'm right!!!

 

Thanks for the suggestion but I already checked. I also have a 98 Blazer and have been running between the two checking different things. The ignition coil driver wire (the white/black wire) does not flash just stays solidly lit. When I check the 98 Blazer the wire causes my light to flash. The wire has power I just dont know what makes the thing flash. Any thoughts?

 

I plugged the Blazer up and got a new code P0336. I did change the engine and while doing so changed the crankshaft reluctor wheel from the bad engine to the good engine. I did buy an aftermarket cover because the cover said to put a new one on when replacing. I switched the CKP sensor out with the 98 Blazer to make sure they both worked and the 98 runs just fine so I do not think it is the sensor. I did read about a CKP System Variation Learn Procedure but the link I found posted by someone else on the forum would not come up. From what I have read it looks like I need to take the thing to the dealer and have a leval II tech scan the Blazer. Is this true or is there something else I can do besides pay the dealer.

 

This may be a dum question but have you tried putting the the coil & ICM (Ignition control module) in the vehicle that is going to rule this out.

Got this of chilton, hope it helps.

DTC P0336 Crankshaft Position (CKP) Sensor Performance


NOTE Applicable vehicles:

• Blazer, Bravada, Envoy, Jimmy, S10 Pickup, Sonoma (VIN S/T)

DTC P0336 Crankshaft Position (CKP) Sensor Performance
Refer to Ignition Controls .
Circuit Description
The electronic ignition control module (ICM) sends a reference signal to the powertrain control module (PCM) seven times per crankshaft revolution (7X reference) in order to indicate the crankshaft position and the RPM so that the PCM can determine when to pulse the ignition coils and control the ignition timing. The ICM applies 5 volts through the 7X reference circuit to the PCM. The PCM switches this circuit to ground for a very short period of time. The seventh pulse is the sync pulse and is used for crankshaft position reference.
Conditions For Running The DTC

• The engine is running.
• DTC P0340 or P0341 is not set.

Conditions for Setting the DTC
The CKP resync counter exceeds 15 within 4 minutes and 15 seconds.
Action Taken When the DTC Sets

• The malfunction indicator lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the malfunction present
• The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers.
• A history DTC stores.

Conditions for Clearing the MIL/DTC

• The MIL will turn OFF after 3 consecutive ignition cycles in which the diagnostic runs without a fault.
• A history DTC will clear after 40 consecutive warm up cycles without a fault.
• The DTC can be cleared by using the scan tool.

Diagnostic Aids

• Inspect the CKP sensor harness in order to ensure that it is not routed too close to any non-engine related electronic component or harness.
• Inspect the wiring harness for damage. If the harness appears to be OK, observe the medium resolution resync counter on the scan tool while moving connectors and wiring harnesses related to the CKP sensor. If the medium resolution resync counter still does not count, then while still observing the scan tool, operate any non-engine related electrical components on the vehicle. A change in display will indicate the location of the malfunction.
• A rubbed through wire insulation or a poor connection may cause an intermittent problem.
• A defective reluctor wheel or a cracked or damaged CKP sensor can result in an intermittent. Remove the crankshaft sensor and inspect for any damage. With the CKP sensor removed you can also inspect the reluctor wheel through the hole. Check the porosity and condition of the wheel. The reluctor edges must be square. Look for nicked or damaged reluctor wheel.

Test Description
The numbers below refer to the step numbers on the diagnostic table:

1. When a medium resolution resync occurs, engine stumble should also occur. If a components connection or wire is malfunctioning, an engine stumble or a medium resolution resync may be induced by wiggling the circuit and/or connector.

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