miss fire no code
 

i have a 97 silverado with a 5.7 in it with 215,000+ miles

i am getting a bad hesitation/misfire? when going from a stop. i am not getting a check engine light or anything. i got this truck not to long ago and wires cap look new i pulled a spark plug and looks new also.

i dont want to just start throwing money at it.

any suggestion?

i didnt find a vacuum leak.

Re: miss fire no code
 

Do you have Access to a scanner You could see if it Has A miss Fire counter And it Will tell you what Cyl is miss firing, might even be a Injector

You mean "no CEL"
 

I have this problem all the time. 9 times out of 10 it's the cap and rotor. Don't ask me why it never gives a CEL. I haven't figured it out.

What I do know in my case was the vents in the replacement aluminum distributor got clogged and it killed caps and rotors in just 300 miles. Not kidding.


GM released a service bulletin in the late 90's to remove the vent screens in the OEM distributor.

First place to start is look at your cap and rotor.

Just an FYI. I had a good cap go bad and replaced it with 3 different AC Delco caps before I got a good one. RIGHT OUT OF THE BOX.

Re: miss fire no code
 

:agree:

Re: miss fire no code
 

I get a intermittent misfire on #6. Get the CEL. Changed cap ,rotor , wires and plugs and still happens. Going to check if still has vent and will remove if there. 1997 Silverado I think 5.0 engine?

Re: miss fire no code
 

The vent is not your problem. The vent will cause a very fast corrosion on the cap and rotor not an immediate problem. It's not the cause of your problem.

Remember it takes 3 things to light off a cylinder.

Spark
fuel
compression (some say air)

The next logical thing if you have spark is fuel. Or should I say lack there of.
If you had access to a good scanner, you could try shutting off the injector and turning it back on to see the change in idle.

If you haven't used injector cleaner on a regular basis. I highly suggest putting 8 ounces in every tank for a few months.