So, how does the motor "feel" to you? Think it's missing? Did you try the mid hill thing again?

 

Yeah tried the up mid hill thing and it did it again, a little less, oh and checked something that was bugging me, and the vacuum line from the intake to the part on the end of the fuel rail (sorry no clue what it's called lol) turns out that it was plugged, cleared it out and it still does a little so not much change. After talking to my mom she said it seemed fine when she test drove it. Since wasn't sure if it was acting normal or not. But just dumped some sea foam in the oil and then some in the gas. Granted half a can in each. So gonna try it again in 20. Probably will do a little more of a test like a few miles down the road, and up a couple semi big hills nearby. Will let ya know how it turns out, and if ya can maybe think of something else please let me know.

 

I'm working on it. If you would, check the intake manifold bolts for tightness on the #6 side (passenger side). 28 ft/lbs, no more than that and from the front to the back of the manifold.

The thing on the end of the fuel rail is called the Fuel Pressure Regulator, it's vacuum controlled. At low rpm (vacuum is highest) it pulls in the diaphragm off it's seat (open) and allows excess fuel to run back to fuel tank. At high rpm (vacuum is lowest) the diaphragm is left on it's seat (closed) and lets no fuel go back to fuel tank. Keeps the fuel pressure high to meet the demand of the injectors.

You said it was clogged, what was it clogged with? Are you sure it's open? If it wasn't even working then it was always closed. Really curious.

 

Oh it was clogged, cause replaced it with a spare piece of hose I had, but apparently it had a lil piece of plastic in it. Pulled that out before test run a few min ago. Will check the bolts on Monday, but on the drive it seemed at first okay but then at stops it would low idle and stutter. Up hills didn't seem to be a issue at first then seemed like the rig was struggling a little. Also when the stuttering at stops started there was a rythmic thumping, at first it was just thump thump thump, then 3 quick thumps, then back to the 3 slow thumps then 3 fast again. Also got new data off the code it threw on the test drive, unfortunately still the same not helpful codes that it has thrown a few times, but the data is a bit different now. Here it is and I do hope that it will help somehow


DTC for which Freeze Frame was stored P1316
Fuel System 1 Status Closed Loop
Fuel System 2 Status Closed Loop
Calculated Load Value 26.27 %
Engine Coolant Temperature 150.8 °F
Short Term Fuel Trim - Bank 1 -7.03 %
Long Term Fuel Trim - Bank 1 -5.47 %
Short Term Fuel Trim - Bank 2 -8.59 %
Long Term Fuel Trim - Bank 2 -5.47 %
Engine RPM 718 rpm
Vehicle Speed Sensor 0 mph

 

Freeze frame is not showing #6 - P0306, just the excessive emissions. What grade of fuel are you using? Regular or Premium?

 

Are you using the AC when you hear the thumping?

 

Yeah I did think it was a little odd there was no freeze frame for the #6 code, will be re-running the scan tomorrow, and just use regular as far as fuel cause the 13-15 mpg it gets I can't afford anything more really lol, and no a/c when hearing the thumping. Had everything off, that and it was bout 40F last night when I took that drive :P. Will get back to ya tomorrow with maybe updated results on the scan and after tightening the bolts if they need it.

 

Well today went out and tooled round with it till I started getting super frustrated. Checked the manifold bolts all were good, then I proceded to swap round the coil packs for #6 and it still is on 6 so that's not it, tried the VSS unplug and see if that changes anything and nupe nothing there. Oh the picture is where the thumping is coming from. Not sure if its just cause of the missfire or what. It's the cover for the plenum. Not sure what else to try have checked all the wires and plugs, the coil pack, replaced injectors, checked VSS (via unplug method) all vacuum lines seem to be good, not sure about the PCV valve and even if that would be a issue. Also checked the ECU for rust damage and none there. Am out of ideas, probably will check the O2 sensors even though they are brand new and check for nastyness on them, and replace fuel filter as I was going to anyway. Well back to hours of google search, and with any luck we can come up with something :S

 

Think for a moment, you swapped out the coils and the #6 problem did not move. That tells me the problem isn't with the hardware but the wiring. Injector plug all the way back to the ECU. You've done everything else to eliminate, wiring is the only thing left.

Two other issues you brought up you need to be positive about because they do effect how the engine runs, spark knock, idling. The PCV has a direct effect on idle speed. Check it, clean it if needed. Double check the fuel pressure regulator because I'm not so sure you've nailed that down. No vacuum leakage through the short hose, fittings nor through the diaphragm.

An issue that came up in another thread in the DII section was an individual was receiving misfire codes for cylinders and the O rings where cracked, dry rotted at the cylinders that popped the MIL. Did you check, replace those as well with the fuel rail, injectors?

 

Yeah you have a point, went up a little bit ago cause got restless and wanted my baby workin again so wanting to try to figure it out soon. Checked the pcv (well what goes for a pcv) valve and it was a little dirty so cleaned it off, then got curious and decided to run a compression test.. well low and behold the compression on cyl 6 is between 34-35 (needle was between the two) So after finding out that just put everything away cussed to myself silently and locked er up. Also I know can be head gasket, but there is no coolant leakage and no coolant in the oil. I know that low compression can either be valves, rings, etc etc. But after the new injectors and rail and misc other little parts trying to get it back on the road right.. well it may as well be a new rig (cost wise) I truly do appreciate all the help you have given me.. and thank you again.

Bobby