2000 3.0 has vibration/lugging between 1200-1500 RPM in gear and out of gear

[bills4065]

My truck has air being introduced into right valve cover off intake air manifold. Pcv valve on right side manifold on my truck and pcv tubing routing back to intake air manifold for reburning of any crankcase vapours. sure you would have similar set up.

 

[fij]

you think this dent in the harmonic balancer is enough to throw off the balance? I changed wires and no change. I ordered a Cam Synchro(I figured it was probably due for it anyways). I'm really leaning to harmonic balancer. None of the parts i've thrown at spark system(fuel filter, coil, wires) has changed the RPM range of concern at all. If I rev up quickly I don't get any hesitation. I would think if the bearing/bushing were going that a quick stomp on throttle would cause some type of hesitation or exacerbate the issue.

 

[alwaysFlOoReD]

The harmonic balancer is the cast iron portion. The stamped steel is a belt pulley. I really doubt that dent would cause your issue.

 

[fij]

Well i've done some more work but not much futher in the fight. I changed cam synchro and harmonic balancer. it did seem to lessen the issue but its definatly still there(1300RPM at stop) I did some more detailed driving analysis. It does appear to be more of a load issue. it is occuring at lower rpm and higher load. I thought previously it was purely and RPM issue. I did replace one leaking injector. I just realized that I possibly bought a non flex injector and put it in a flex truck with regular gas heads. haha. I"m going to get another injector tomorrow I can do some troubleshooting with. I did hook up the forscan and saw some graphs for live data. I did see some misfires occuring in the target RPM. I'm having trouble finding a screen that will show individual cylinder misfire though. I had to get dinner rolling so had somewhat limited time. i'll do some more forscan tomorrow. I did notice on the live data that bank 1 long term fuel trim was consistently high 10% and got up to 17%. Unfortunatly that is the bank that I need to check on the fuel injector to make sure its the right flow rates. I really hope this whole thing wasn't because I clicked on the wrong part for the fuel injector. so next is injectors. maybe pull plugs agian and see if anything looks weird. Maybe a fuel pressure tester. i'm fine buying a tool now and again but geez this is getting to be an issue. Cam synchro didn't look bad at all but maybe i'll reset position with acutal top dead center. I just replaces in same position.

 

[fij]

injector was correct injector. I bought another one to do some testing. swapped in, now two, brand new injectors. I'm going to do all the injectors in the next week or so. injectors I pulled the screens look pretty clogged. I checked for vacuum leaks. i'm reading 19 inches vacuum. I think thats fairly normal. when I hit gas it goes down to 0 pretty much but jumps right back up. I checked long term fuel trim and bank1 is still sitting at +10. I reset the preprogrammed values in the PCM with the forscan tool. Started up normally. watched long term fuel trim slowly build back up to +10 on bank 1. bank 2 just stayed about the same. This is a damn mystery. I guess I can get a fuel pressure guage and check fuel pressure and see if its acting funny. I checked the fuel rail diaphram. pulled vacuum hose to it and smelled it. fuel pressure guage will tell me if its actually doing its job. hoping for any input from folks.

 

[fij]

well.... it was the fuel injectors. that or I knocked something clear in the upper intake removing and replacing it. runs great through trouble rpm. took it on the road and low rpm driving is a dream now. I do have some cold idle roughness still. I don't think that was tied to the lugging. on to the next piece of the project.