installed headers. cars missing.. please help!!
Thread Starter
Teching In
Joined: Mar 2008
Posts: 2
Likes: 0
From: Cumberland MD
installed headers. cars missing.. please help!! ok so i just installed a new set of pacestter headers and y pipe on my best friends car yesterday.. its a 2000 z28. with 60k miles. the car already has an slp exhaust on it and an intake. no other mods tho. the install went great! easy install. we also put new plugs and msd wires on while we had it apart. hooked everything back up and all the hoses all the wires o2s everything! started the car sounded awesome ran great until we got on the main rd and mashed on it.. the car ran strong in 1st and 2nd gear but in third we could hear it was missing at full throttle.. but only at like 80% throttle or more... it doesnt miss unless the engines under a load. i looked at it more 2day made sure that all the vacuum lines were on good and all the wires were on all the way everything checked out good but its still missin when we mash on it.. i dont understand why tho.. ive never had this problem on a car before.. im going to pull the plugs tomorrow to see what shpae there in..
the car has not been tuned. could that be the problem?
could running too lean make it miss?
also the car has no cats and no mufflers now could back pressure be the issue?
anyone wh has gone through this or anything similar any input would be helpful!! we need to get this beast runnin 100% again!!! thanks, sean!
the car has not been tuned. could that be the problem?
could running too lean make it miss?
also the car has no cats and no mufflers now could back pressure be the issue?
anyone wh has gone through this or anything similar any input would be helpful!! we need to get this beast runnin 100% again!!! thanks, sean!
My car did the same thing this week after the lt install..turned out to be a plug that had a hairline crack in the porcelain..check all the plugs and make sure there ok..also test the wires using a ohm meter set at 20k the stock wires will run ~.36 and aftermarket wires~.03 resistence....and run the ses codes or wait for them to pop up
well as im not sure of your problem i can contribute this info i did a h/c swap and headers keep in mind the headers are open no exhaust no back pressure but it ran awesome expecially full throttle the only problem i have is it sufficates below 2k rpm till i get it tuned not being tuned could be your problem but i doubt it is leaned up that much i would start with the plugs see what they look like also check to make sure they have the right gap also your problem reminds me of this product it could help http://www.lmperformance.com/2578/1.html
