engine performance

[studabaker]

I have an elmscan 5 to connect to the obd port however I am not sure what software will improve on the elm327 bluetooth i have on my phone. I am having low voltage on both banks and I have been replacing coil packs and improving the ride in many ways. the moog sway bar linkages have made an incredible difference. I also tightened down the frame bushings which was free and made a significant difference. I finally repaired my airlift bags inside the springs which has helped. I did the head gaskets which has made a significant difference and now I am able to notice some other issues now that I have eliminated most of the other vibrations. The engine has a murmur kind of issue and I have the obd thing for my ohone and it shows low voltage intermitently but I dont know how to identify which coils are the issue and when I replace one it helps but bank 2 are all new and I am still getting a low voltage reading on that bank?

What program should I get that can do more advanced stuff?

How could I identify a short, could there be a intermitent short somewhere and how could if find that?

How can I get the engine to run smooth?

I am pretty happy to be where Im at with it running and everything being resolved in my suspension. Now I notice the engine clearly vibrating through the whole vehicle when there is low voltage. At least I can tell that I have low voltage once on each side. Just keep at the coil packs. They short to the block I guess...

Thanks

 

[1955moose]

Where the heckel you've been? Thought you died, or fell into a well! Do like our new friend Toby says and try disconnecting the coil wires one at a time, fire it up and see what happens. I don't think your problems coils, if your changing that cylinder and hopefully the boot with the coil, and still throwing the code. Your next step is the injectors individually, especially #3, and check the harness going to each injector. Lastly, check or have someone check the back pressure on the 4 cats. Some of the troublesome misfires have been traced to a cat or 2. If memory serves, didn't you change the cat's last year? Good to have you back.

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[studabaker]

I replaced my pcv hose elbow because i was getting O2 reading of 0.8 and sinusodal graph on my phone. The trick was knowing that the O2 sensor should be steady at 0.5 or near to it. Once I checd that graph using the elm327 and torque app on my android phone I was able to conclude that I had a vacuum leak. I got the valve cover gaskets and as I was removing my passenger side there was one bolt not tightened from when I did my head gaskets. I is also importat to know that my passeneger side was the one reading 0.8 right away and they are required to warm up to be able to have a voltage. I think i may still need to do the valve cover gaskets but that is exactly what i was going to do today and really expected to find boots shorting to the block. I feel like i hear it arcing to the dash board some.times. I still may have that going on too but I am gradually eliminating problems and it really is a pleasure to drive it is so smooth when it is running good.

Thank you toby

 

[1955moose]

It's always a good bet to change all the boots around 100-125k, not so much the coils unless they get wet. Plugs of course. You've got your hands full. Did you ever get rid of the vibration from last year?

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[studabaker]

I have been replacing coils and spark plugs and i had a leaky head gasket and low compression in at least one. I had fuel in my coolant and a gunky build up on pistons so that was worth the effort and certainly a learning experience. I had damage from the wrong sized rotor bolt holes 14mm on 12mm bolts which damaged pretty much every part of suspension and by the time i repaired one thing the other damage would damage the new parts so once identified and resolved the rotor cause i had to replace cv axles rebuild front diff balance drive lines but it is like new at this point. The moog sway bar links fit the holes in the sway bar and are awesome and i had to order the valve to the air lift bags which took some time but i am smooth sailing with some minor engine issues. I got a set of injectors for 80 bucks which turned out worse than before. 2 did not function at all. Well see. I of course want to resolve running issues one the new gaskets and suspension to not damage that. That you for the reply. I have been working hard at it this whole time. The passenger valve cover was such a pain until i discovered the hose and wiring bolted onto the back. I actually damaged the pipe off the water pump going back to the back of the engine, in the process of removing it. It was slightly bent and leaked when i installed it. Luckily they had one at the dealership. That heater core hose makes the valve cover annoying to replace. I have the understanding to lift up on the wires and reroute them while i stalling the valve cover on that side. I also remove the pcv hose all together. That thing has came loose a few times. Thats my go to first check in rough idle.

I would still like to be able to look at individual cylinders on my computer to id low voltage, like the dealership. I had put rtv on my coil connectors when they broke the retaining clip. This creates an issue to just unplug one at a time when there were maybe 4 like that. I have the pigtails and heat shrink to reapir that. I think they mostly stay..... so im gonna do that. After i get vacuum leaks resolved which this appears to be.

Thank you for the reply.

 

[1955moose]

That's whats happens with heat on plastic. Anyway glad your back. You've got a ton of real life fix it experience, don't be afraid to jump in. We get some one off items that can use your experience on those issues. You've worked on your SUV, stem to stern! And now you've come out on the other end.

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[studabaker]

Do you guys use any programs to monitor your engine? I am having a kind of misfire. I am not sure which cylinder. The dealership was able to tell which cylinder had low voltage. I can read the o2 sensors and they are wonky on bank one. This suggests a vacuum leak. I did my valve cover gasket again and maybe slight improvement. I plan on replacing sections of vacuum hose. There are a couple pieces that look old. I need to do that pressure smoke test maybe. I will get some injectors but i just did the o2 sensors and that semed to have slight improvement but the misfire feeling persists. The dealership showed low voltage to nunber 2 and 3 but it is just low. Not a complete misfire. My #1 and 3 have the pigtails broken, just the retaining clip. I have replacement pig tails. The are pretty snug on there and dont move... I will focus on vacuum leaks tomorrow.

 

[Ulver]

Hello Studa. If you can study fuel trim live data, you will without a shadow of a doubt have way more diagnostic capabilities. I'm not an expert by any means, but I feel like I've been able to go figure out a couple things (including vacuum leaks), just by knowing how to read the data.

 

[studabaker]

I am not sure what exactly a rich bank 1 means. I can do a vacuum test maybe to confirm but another meaning is that I have a bad injector, or some other kind of misfire? If I could isolate the cylinder that is the problem and replace everything. I am planning on doing the injectors on bank 1 next week. The top graphs are bank 1 o2 sensors. the bottom graphs are bank 2 prior to beng warmed up. bank 2 goes up to .5 once it warms up. Bank 2 has some minor jumps but mostly steady at .5...

 

[TobyU]

I don't worry too much about o2 numbers. Fuel trim are good for vacuum leaks but misses will show up in misfire counts in scanner results.