royce777

iTrader: (29)

We will have to look into it. Thanks for the info!

Cobalt_noob

PMed you man.

Hey btw, I wanted to throw this out there, I put a couple of clamps on the hose going from the evap canister to the throttle body..... The whole time before I've done that, my wideband was reading between 14 and 14.9 (bouncing between that) and then I'd would go super rich really quick and then back to the 14 to 14.9 again.
So I put the clamps on that hose, and now, I'm running lean at about 15.6 and 16.2 fluctuates
Any thoughts on that one?!?!

royce777

iTrader: (29)

Who did you SC install? Is it a ZZP kit? When we meet up I will look over everything. Im not really a M62 guy so I can only give so much advice but I do know how to work on anything

Cobalt_noob

I installed everything... like 4-5 times now lol! but i did it mostly by myself with a bit of help from some close friends. This is just been an on going issue with the misfires. Yeah definitely take a look. And yes its a ZZP kit.

klotzy_550

iTrader: (1)

Im not sure I am following, did you end up disconnecting the EVAP system or connect it?

If evap is disconnected your injectors will reduce their injected quantity when the ECU is commanding a PURGE event. The idea is that the fuel vapor volume that is injected will make up for the reduction in injected quantity. However, I wouldn't think that the ecu is commanding a constant purge signal at idle. When I had the blower on my car it wasn't a huge fan of idle transients initially. When EVAP or the AC clutch with kick in or out the AFR would swing lean to rich to stoich. This is where you can start to tell that HPTuners and other aftermarket tuning programs do not have the same control as ETAS INCA with the ecu's A2L file. But you have to work with what you got.

Cobalt_noob

Yes, i have the evap connected, i just added some clamps to further secure the hose better.

Because i bought the phenolic spacer for the intake manifold, my belt could no longer stretch around the AC pulley, there was just no way of making that happen without getting a bigger belt DEFINITELY! So as of now, i have no AC at all.... could that potentially have something to do with misfires then??

klotzy_550

iTrader: (1)

The only times it happens is when the AC clutch would engage / disengage since it either is a large inrush of current (alternator load) or unloading also the torque required to compress the refrigerant. This is where drag torques / RL prediction terms come into play. On an OEM setup / calibration A/C enabling is pretty seamless because the ECU can accurately predict how much air / fuel to provide to account for the extra loading from the AC clutch and compressor.

jdbaugh1

iTrader: (1)

I may be misunderstanding here but how the heck do you have your belt routed if it doesn't g around the AC?

Cobalt_noob

Thank you for the cogent response to that, I have learned something new! Would a higher output alternator make up from some of that draw, or is this the nature of the beast?

I can tell someone has been/is going for some form of engineering! Im going to take a wild shot and guess Mechanical Engineering??




well.... depending on how you (you specifically) install your belt, i always slip it over the S/C pulley last. It just works out that way. Starting from the S/C pulley and working down, the belt goes underneath (smooth side of belt) under the idler pulley, then just a short reach to the alternator pulley and then below that it would then loop right over the AC wheel.
Since the phenolic spacer is installed (and its just a slight squeeze to get the belt on with out the phenolic spacer) the phenolic spacer extends the S/C out by maybe an inch or so. So instead of looping from the alternator to the AC wheel, it just shoots all the way to the Crank Pulley.

Cobalt_noob

Um, so yeah, pulled all of my spark plugs and they have oil all around the threads!!!

I didn't notice any around the electrode though, just the threads of the plugs. Anybody know what that means????

Cobalt_noob

Alright, not going to beat a dead horse here. Just going to leave it on this note, any input would be awesome.
The oil on the plugs could mean just a bad valve cover gasket. Got it. But with what's going on im inclined to lean on other possibilities, just will not know that for sure until a leak down test.
After doing the compression check and reading 150 psi on all the cylinders, obviously rings are worn and/or engine as well. Which is BS on different levels. In conjunction to that, I believe there is something going on with the valves, valve seats, guides and seals... Just a hunch. Again, leak down test will turn something up.
As it stands now until I do a leak down, I'm thinking its time for a new engine altogether. 2006 or 07 for the forged internals. Does anybody have a site they could recommend that has a good reputation on selling used engines?

Also, after soldering the coil wires, at idle there are overall less misfires. But now, I'm getting the flashing CEL if I lean in to the gas a bit. In other words, f**k this damn car! I'm sure the tune. Anyways, ill update.

klotzy_550

iTrader: (1)

Higher alternator would still exhibit it might be worse might be better. Think of the alternator as a loading source, the stronger the alternator the more torque it can absorb. So it may load the engine harder during current transients but for not as a long as a weaker alternator.

Studied mechanical engineering for undergrad, controls engineering for grad, and currently work as a powertrain calibration engineer for an OEM powersports company.

royce777

iTrader: (29)

This still makes me think there is a electronic gremlin going on. I would thoroughly inspect over the engine harness. Also how did you extend your wires for the MAF?

Cobalt_noob

Its an extension harness provided by ZZP. Came with the kit....

I am right there with you on the possibility of a electric gremlin somewhere. At the moment, describing this issue is like a web diagram. The central topic, Misfires. Everything that branches from that main issue has got me all over the place.

But that is highly a possibility and have looked in to purchasing a whole new engine harness or as we discussed, a pull-a-part.

If this weather clears up, you still ok for the CKP relearn today or we can take a rain check?

royce777

iTrader: (29)

I will shoot you a text, I should be good for today but it may be a little later.

Cobalt_noob

I'm starting to wonder if I've got a bad ECM.

I just got a P0171 thrown up.

Before that, it was P0300 and P0455... Then they go away, one time on their own even.

Royce777 and I attempted to do a crank relearn but we think to no avail.

How fast do the fuel pumps go bad on these?

klotzy_550

iTrader: (1)

You may have answered this but do you have a wideband? Could be truly running lean, would result in lean misfires.

Cobalt_noob

Leakdown Test kit ordered and should be here Friday! Really curious what I might find doing this test, im half expecting something wrong with the brand new rebuilt head, but will find out.

To re-cap on the symptoms:
1.) Car has a constant misfire, occurring at idle and WOT mostly.
2.) Idle bounces and sometimes stalls. Will bounce from as low as ~400 rpm then bounce to 900. Will repeat.
It does not happen first thing in the morning when I start it, only when I put load on it does the process start. (It does however misfire in the early morning, but no bouncing idle like its going to die)
3.) Error codes are random and so far have been in this order: P0300, P0302 w/ P0455, P0300 x2, P0455 x2, and now the latest P0171.
4.) Bucks/Cuts out when WOT.
5.) Stalls when idling.

Here is what I have done diagnose what is the issue:
1.) Checked Spark Plugs x2 (Second time there was oil around the threads)
2.) Checked Coil packs (All basically brand new)
3.) Soldered wires on Harness for better connection
4.) Sprayed Starting/Carb fluid for Vacuum leaks (None noted)
5.) Triple checked for vacuum leaks on any part of the car
6.) Compression check on all cylinders (150 psi across all cylinders. Only few psi increase when Wet Test on
Cylinders 2 and 3)
7.) *** Soon To be Accomplished *** Leak Down test
8.) I did a fuel pressure check a while ago (last year some time) and it checked out good to the best of my
knowledge

What parts have been replaced in hopes to cure issue:
1.) Fuel Filter
2.) Coil packs
3.) 4 sets of Spark Plugs (all tried at different Gaps.... a bit excessive, but covered those grounds for sure)
4.) All brand new gaskets
5.) Thermostat and Temp Sensor
6.) EVERYTHING w/ ZZP Kit (*note: all of the parts were BRAND new, never used.. from what ZZP told me.... now i know theyre not selling new parts with the kits now, but they did when i purchased them)
7.) Both O2 sensors

So now, the only thing remains to be changed is the Fuel Pump. I just purchased one AEM High Flow. Possibly a dying fuel pump???

Oh and Royce777 and I attempted to do a CASE relearn (Crank Relearn?) as it is not the original engine, and i have installed new crank sensor and cam sensors since. Never had a code come up for it, but we are not sure if we successfully accomplished the CASE relearn as the directions were vague, and we're not sure if my car is cutting out on its own, etc.. etc...

I'll update what the leakdown test reveals (if anything) and go from there. Any input at all is appreciated so please, drop some ideas!

Ive read countless of other forums on different vehicles and every similar case had something off the wall that was causing those peoples cars to behave exactly how mine is (or vice versa)... So im just completely tapped.

Cobalt_noob

I do, and it seems to be fine if im cruising.. like its in the 14.1 to 14.9 range if im cruising. It does however bounce around a bit, but it returns back to this range. I can tell its compensating for something (whatever the issue is) as to how all over the place it is.

If i do step on it WOT, it goes way rich at 10.0 which is good i guess, but im still having that bucking issue.

Oh and at idle its partially lean.. 15.4 ish ... but if im coasting to a stop out of gear, it is completely lean. like off the chart lean. Dont know if thats normal though or what exactly???

klotzy_550

iTrader: (1)

14.1 - 14.9 oscillation is normal, it is designed to run that way to promote higher catalyst efficiency. If it is holding 15.4:1 AFR at idle without really moving that could cause a misfire(s). At WOT 10:1 is too rich for this application, usually a pretty safe number is around the 0.8 lambda (11.76:1 AFR) for peak power / conservative calibration. For the OEM Turbo applications I have worked on, 12.5:1 has been our target (0.85 Lambda), however, every engine is different so take that in to account too. I know my car would buck when it got to the upper 15's:1. So when you state that it is misfiring at idle and WOT, I could potentially see it as with what your AFR feedback is. 42lb injectors? With the 60lb'ers I had to idle slightly rich of stoich which I am not a fan of due to cylinder washing and oil dilution, but it worked.

As for going to free air lean while coasting, that is completely normal. Its a function called deceleration fuel cut off DFCO, does exactly what it sounds like, kills the injectors while coasting. AFR should be pegged lean / free air / off the charts.

Food for thought

Cobalt_noob

Thank you yet again for your cogent response!
The injectors are 60lb. So unless this whole issue is based off the incredibly horrible ZZP tune, which everyone is saying.... I just don't see them tuning something that will cause misfires? I mean I'm not saying the tune is dead on (of course not) but what I am saying is why would they tune that terrible to cause horrible misfires???? I'm not buying it.. I have read of people getting some terrible tunes from them, and anything is possible, but it just doesn't make sense that it would be THIS bad!

I've got the leak down kit today, ive got to figure out a good time to go knock that out. But until then I've got the AEM 35lph fuel pump.... Could a dying fuel pump cause this issue??

klotzy_550

iTrader: (1)

The canned tune they designed is what it is, canned. The reason that GM can get away with it is because the hardware is locked, i.e. engine components. For example, do you run aftermarket, exhaust, down pipe, header, and / or cold air intake? When ZZP made their canned tune it was setup for a specific scenario then the fueling was botched to "try" and make it more suited to differences to engine hardware (conservative/just throw fuel at it, hence richer than 10:1).There is only so much variation that the software will allow for adjusting to the hardware, after the threshold has been maxed out the tune is what it is.

Cobalt_noob

Thanks for your input Klotzy, i appreciate it.


Does anybody know if on our cars if the fuel pressure regulator is built in to the fuel pump itself, or is it a separate piece?

Ive got the AEM high flow fuel pump, but i would like to know where the heck is the fuel pressure regulator??

klotzy_550

iTrader: (1)

If I am not mistaken, the LE5, at least my cobalt used a dead head fuel system, meaning the fuel pressure regulator is either in the sending unit, or somewhere along the way to the fuel rail. But I am willing to bet it is in the sending unit due to less fuel hose required.

I'll put it this way, of all the times I have had my cobalt on the lift I have never seen a fuel pressure regulator and I have gone through the process of swapping a motor.

Cobalt_noob

Okay, so I have finally got time to do a leakdown test on the ol yellow demon.

Basically, the test was inconclusive. I am going to go out on a whim and say that maybe i didn't do it right SO i will do another one.

I will say though, on Cylinder 1, there was abnormally low low pressure. I was putting 90 psi at the gauge and only pulling 30 psi at the cylinder?! Any thoughts?!?

AND FINALLY.... HERE IS THE MYSTERY OF ALL TIME>>>> The misfires are gone! What the F**k!?!?! Gone! 0 misfires at a constant. HOWEVER, it is still spuddering on acceleration and chasing idle.... any thoughts now???