Random misfires

Tiny
RIFLEMAN
  • MEMBER
  • 1999 CHEVROLET VENTURE
  • 3.4L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 107 MILES
Code p0300
I have been working on this for three years. I have tested coils 5.75 ohms on secondary and 1 ohms on primary coils. I have new plugs and wires. New intake gaskets, IAC, TPS, AIC. Map is good. Vacuum holding at 25 psi. Timing light shows cylinders one and five random misfiring. It also has a new cam sensor. Could a bad knock sensor be causing this. I tapped on the engine and no change in rpm's. Can you help thanks.
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Saturday, September 10th, 2016 AT 10:47 AM

7 Replies

Tiny
HMAC300
  • EXPERT
Best thing here is to have a mechanic look at it he can freeze frame to see if a sensor is bad as they can cause the problem as well as injectors or a basic engine problem. These are very hard to find and having a mechanic do it actually will save money because you are not spending on parts that are probably good.
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Sunday, September 11th, 2016 AT 8:20 AM
Tiny
RIFLEMAN
  • MEMBER
Thanks. I was already contemplating on that. Most likely that is what I am going to have to do.
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Sunday, September 11th, 2016 AT 9:43 AM
Tiny
KEN
  • ADMIN
Please let us know what you find so it will help others.

Best, Ken
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Wednesday, September 14th, 2016 AT 7:54 PM
Tiny
RIFLEMAN
  • MEMBER
Will do as soon as my work load changes. I have a few more things I'm going to test before I take it to the shop. I'll keep you informed. Thanks
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Wednesday, September 14th, 2016 AT 7:59 PM
Tiny
KEN
  • ADMIN
Hey,

Did you ever get the problem fixed?

Best, Ken
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Wednesday, December 21st, 2016 AT 1:41 PM
Tiny
RIFLEMAN
  • MEMBER
I did a few more test with the timing light. I found out as the van warms up coils 1 /5 starts randomly missing. I believe that I'm losing the secondary on the packs. I haven't had much time to mess with it. Soon as the weather breaks I'm going to replace all the packs with new ones. I tried ones from a junk yard but it ran worse. I'll let you know once I change them out. Thanks for asking.
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Wednesday, December 21st, 2016 AT 4:27 PM
Tiny
KEN
  • ADMIN
Please use 2CarPros anytime, we are here to help and tell a friend.

Best, Ken
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Thursday, December 22nd, 2016 AT 12:50 PM

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