| Slant Six Forum https://slantsix.org/forum/ |
|
| Need help diagnosing a "miss" https://slantsix.org/forum/viewtopic.php?t=19234 |
Page 1 of 1 |
| Author: | Slanted Opinion [ Thu Aug 17, 2006 5:11 pm ] |
| Post subject: | Need help diagnosing a "miss" |
Hi folks, I pulled my slant to replace a cracked exhaust manifold, clean and degrease the block, and replace oil pan and valve cover gaskets. I replaced the intake-exhaust gasket (Napa) using the directions posted by Doug Dutra. On fire-up I have a pronounced miss, seems to be quite regular, like one cylinder misfiring. I'm guessing that I may have a vac leak on the intake. How do I check this? Seems to me that carb cleaner sprayed around the intake ports was an old trick. I suppose I could pull all the plugs and look for one that is different in color. Any thoughts? Additionally, I'm afraid I may have cracked into the coolant passage on the rearmost exhaust stud. A small leak showed up there. I sealed the leak around the stud... but will this cause trouble? One final note... just before this engine pull I had a significant overheat... steam everywhere. Perhaps I cracked a head or blew a head gasket? The engine doesn't overheat at this point, but I've only had it idling so far. Thanks as always for your help. -Mac |
|
| Author: | DusterIdiot [ Thu Aug 17, 2006 7:45 pm ] |
| Post subject: | A few things to ponder... |
One way is using the carb cleaner and listening for the idle to speed up.... If it's ignition oriented you can use a test probe to "short out" your plug wires one at a time until you find the one that causes the miss...(the one that doesn't cause a change in the idle). If you swapped out the exhaust manifold, then you might have a mismatch between the runners on the intake and exhaust...if combining stacks you may want to have them planed...if on some kind of budget you can spend a little extra $$$ and get the Mr. Gasket #320G "thick" gasket...it helps out a lot... Depending on how the mixture is you may not notice the "lean" cylinder when checking plugs( it may be as tan as the other ones, but lean enough to make that "puff" sound). Then again if it is fouled, cleaning the plugs may help. -D.Idiot |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|