97 Z71 misfires

Page 1 of 2  
Hi, I have a 1997 z71 with 5.7l. It started missing bad. Replaced cap, button, wires plugs and it still does this. I have it at the local shop and he is scratching his head. Scope shows misfires on 5 and 6.
With a good coil and 125 psi compression what else could it be?? I have been reading here so please if you have helpfull suggestions PLEASE post them. If your intent is to childishly bicker and criticize others then move on. Thanks in advance!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@aol.com wrote:

Check for intake leak.
Alan
--


NHRA POWERADE CHAMPIONSHIP 2007
THE MOST EXCITING SPORT THERE IS..
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Doesn't this year of Vortec have individual coils per cylinder like the newer ones? Have you tried switching coils around and see if the miss changes?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Augustus wrote:

Nope, I got one myself. Distributor, 8 wires etc.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article
snipped-for-privacy@aol.com wrote:

Plugged injectors. Exhaust valves not opening.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 25 Feb 2007 12:51:55 -0800, snipped-for-privacy@aol.com wrote:

Is that 125 on all cylinders or just those two as it is a bit low. Also have you done a wet and dry compression check on them? (with oil squirted in cylinder for wet test) Might check crank posotion sensor as it provides a timing referance and also the magnet pickup coil in distributor (they call it a cam position sensor now but it is still basically the same thing but the new name sounds more hightech). Might do a fuel pressure check to see if it is fuel starving a bit too and change fuel filter if it has not been done yet. ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

For what seems like the 4000th time, it is not the same thing and has nothing to do with the function that the previously used distributor pick-up coils did. Cylinder identification only so the injectors can be fired in sequence (or 'sequins' in your book).
You must get your rocks off sending people on wild goose chases.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 26 Feb 2007 14:39:08 GMT, aarcuda69062

I guess you cannot follow the posters request huh, you are a real troll!. BTW, you can call it a CPS till cows come home if it makes you happy but you need to focus more on helping and less on being a arse and getting you ducks in a row too. ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

BTW, if you knew half of what you claim you would know that while the CPS does not normally cause timing problems it does provide a 1 X signal to VCM (crank position sensor provides a 4x signal on V8's and 3x on V6's) that is used some for misfire diagnois by VCM and DTC code generation related to misfire so it is not out of the loop as you claim. ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Actually the CMP is a .5 (1/2) X signal, if you follow GM convention of pulses per CRANK revolution.
VCM = Vehicle Computer Module, correct?
Toyota MDT in MO
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

You owe me a keyboard!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Snofraud, he already knows that it is misfiring on cylinders 5 and 6 (IOWs, the cam position sensor is doing its job). So, other than some overwhelming desire to be exceedingly obtuse, what's your point?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Read what I wrote Snobozo.
I never said the cam position sensor was "out of the loop." I merely refuted your assertion that it functions and performs the same as an HEI pick-up coil. It doesn't, no matter how much you want to believe it does.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm under no obligation.

Correcting your errors does not make me a troll.

Would "getting my ducks in a row" mean correctly identifying a component and its function in the system?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 26 Feb 2007 14:39:08 GMT, aarcuda69062

You should know because you quack or honk more than anyone ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What kindergartner gave you that one?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

It is reflective of his highest level of education.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

And Trolls sometimes travel in groups too. ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Nah, when it comes to dealing with you I sorta think of myself as a proctologist.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.