96' 5.7L misfire on cyl. 3&5 HELP!!! - Chevrolet Forum - Chevy Enthusiasts Forums

96' 5.7L misfire on cyl. 3&5 HELP!!!


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Join Date: May 2009
Posts: 5
N. Charleston, SC

May 4th, 2009, 6:09 PM   #1  
CF Beginner
96' 5.7L misfire on cyl. 3&5 HELP!!!

I have a 96 Chevy 1500 w/5.7L. Truck cost me little to nothing and I found a great project truck. It is missing on cyl.'s 3&5. Code P1345 is the only thing logging in the ECM.(Crankshaft position sensor/camshaft position sensor correlation) I have replaced Ign. control mod., coil pack, plug wires, plugs, crank pos. sensor, dist. w/camshaft sensor, rotor butt. and dist. cap. I have checked the Ohm loads on the wires(good) plugs gapped correctly, Tested coil pack and Ign. control mod.(good). I know it's these specific cyl. I checked them the old fashioned way, pull the plug wire and check w/finger!! Is there something I'm missing?? Is it possible that something simple is throwing the wrong code?? ANY HELP would save me a few dollars on Aleve!! The headaches are starting to take a toll!!!!

 
Join Date: Jan 2009
Posts: 338
No. Md

May 5th, 2009, 9:16 AM   #2  
Banned
Are you using the correct plugs? For example, if you put platinum plugs in a saturn it will misfire.

Second make sure the ground wire is not corroded and is firmly attached. Check the connectors for the coil and the ICM to make sure they are not corroded. Did you use dielectric grease?

 
Join Date: Apr 2009
Posts: 139

May 5th, 2009, 9:30 AM   #3  
CF Active Member
Is it the plugs not giving sparks?
Or is it the cilinder not getting any gas?

 
Join Date: May 2009
Posts: 5
N. Charleston, SC

May 5th, 2009, 4:57 PM   #4  
CF Beginner
The cylinder is getting plenty of gas it's just not getting fire from the distributor. I checked the plugs and they are the factory replacements from Chevy. Ground wire is in great condition and everything plugged into the ICM properly and secure. Yes I used dielectric grease. The only thing I can see is the ears on the distributor that the dist. cap screws into are cracked. Looks like I may have over tightened a bit. Could that be causing the code?? It's odd to have misfire only on one bank of the dist. It has me confused!!

 
Join Date: Mar 2009
Posts: 1,659
Michigan

May 5th, 2009, 6:39 PM   #5  
Super Moderator
sounds like timing to me when you put the timing back to factory specs? And when you timed it did you unplug the timing bypass plug under your glovebox?

 
Join Date: May 2009
Posts: 5
N. Charleston, SC

May 6th, 2009, 5:49 PM   #6  
CF Beginner
I didn't know there was a timing bypass plug. I guess I'll try that next!!

 
Join Date: Mar 2009
Posts: 1,659
Michigan

May 6th, 2009, 6:10 PM   #7  
Super Moderator
yes the timing is automaticly controlled and if you move it with the bypass still connected you are doing nothing with the truck unplug this wire start it and move timing to factory specs tighten distributor then shut truck off and unplug battery to clear codes with battery still unplugged plug bypass back in, connect battery and start the truck should run better im pretty sure this is your problem.

 
Join Date: Jan 2009
Posts: 338
No. Md

May 7th, 2009, 7:37 AM   #8  
Banned
Using dielectric grease is not a smart idea. I have seen nothign but problems from that. From melting coils to misfires. That could be exactly what is causing your issue.

 
Join Date: Mar 2009
Posts: 1,659
Michigan

May 7th, 2009, 5:12 PM   #9  
Super Moderator
yeah it prevents things from melting how could it cause things to melt????

 
Join Date: Nov 2008
Posts: 2,955
Bowie, MD

May 11th, 2009, 7:47 AM   #10  
Super Moderator
Professional Mechanic
Have you had the distributor out? p1345 ususally occurs when it is not properly timmed. Timming must be set while looking at cmp retard # in the data of a scan tool. The spec should be 0 + or - 2. Anything higher will set the code. You can not time this engine with a light. There is no distributor plug on this truck, only on previous years

 
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