Diag time... Average manifold temp? (little long bare with)
02-01-2009, 03:48 PM
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Diag time... Average manifold temp? (little long bare with) It's time to bring her back... My 'Z' has been sitting for the past few months and I finally have the financial backing to try and get her back on the road. The problem occurred shortly after a full motor rebuild/refresh and a six speed swap. Threw in some higher compression forged pistons, new rings, bearings, decked heads, re-cut the valves, new gaskets all the way around, pcm from MadZ28, and a few other small things here and there.
The car was running strong and was fine for a couple months. Soon after, developed a slight miss-fire. Ran multiple tests (injector-drop test, fuel pressure check, Tech 2 diag, compression test) and pretty much came down to a couple possible problems. Carbon tracing in the opti, small vacuum leak, and the o2 sensors being a little off. Decided to start off doing the usual checks for the vacuum leak, I decided to replace the PCV valve and tubing.
This is where everything went to ****. During the valve/tubing replacement, I didn't tuck the fuel lines back up well enough. They ended up falling on the header and less than 3 miles up the road the car started sputtering and breaking up. Luckily the fuel lines didn't burn through, only the conduit around it. Thought that maybe the fuel had boiled or something, but multiple sources said the fuel travels through too fast and cool, and that the plastic tubing would have melted sooner than it having time to boil. Fuel pressure was only down a couple pounds from suggested stock amount, but nothing that would cause such severe low rpm miss-firing. And compression was building just fine.
After that, I was forced to park it due to money problems and started drivin the 'beater'. Now I'm trying to get back on track. Ran an infrared thermometer on it and the temps were in the 500-560 range on the driver's side, and 620-700 on the passenger's side. Not even sure what the average temp should be, so was hoping somebody who has actually done this and remembers their readings could chime in...
I am also going to do a leak-down test when she cools off and will let you guys know what I find. Any accurate suggestions with possible problems would be awesome.
The car was running strong and was fine for a couple months. Soon after, developed a slight miss-fire. Ran multiple tests (injector-drop test, fuel pressure check, Tech 2 diag, compression test) and pretty much came down to a couple possible problems. Carbon tracing in the opti, small vacuum leak, and the o2 sensors being a little off. Decided to start off doing the usual checks for the vacuum leak, I decided to replace the PCV valve and tubing.
This is where everything went to ****. During the valve/tubing replacement, I didn't tuck the fuel lines back up well enough. They ended up falling on the header and less than 3 miles up the road the car started sputtering and breaking up. Luckily the fuel lines didn't burn through, only the conduit around it. Thought that maybe the fuel had boiled or something, but multiple sources said the fuel travels through too fast and cool, and that the plastic tubing would have melted sooner than it having time to boil. Fuel pressure was only down a couple pounds from suggested stock amount, but nothing that would cause such severe low rpm miss-firing. And compression was building just fine.
After that, I was forced to park it due to money problems and started drivin the 'beater'. Now I'm trying to get back on track. Ran an infrared thermometer on it and the temps were in the 500-560 range on the driver's side, and 620-700 on the passenger's side. Not even sure what the average temp should be, so was hoping somebody who has actually done this and remembers their readings could chime in...
I am also going to do a leak-down test when she cools off and will let you guys know what I find. Any accurate suggestions with possible problems would be awesome.
Last edited by projekt70chevelle; 02-01-2009 at 05:32 PM.
