having serios problem diagnosing 2.5

[vostok]

I'm having a HELL of a time figuring out this 2007 Altima 2.5 and would really appreciate some ideas on where to look next..


So the main issue is the car WILL NOT run properly. It seems to flood intself out constantly. I bought the car and got scammed with a covered up hack job car. looks like it had a front end impact at some point in its life.

So basically I am stuck with it until I can get it running again, even then I wouldn't want to dump it off on someone so ill end up just running it as a second car till the wheels fall off.

SO when I bought the car it WAS running fairly good. No real issues.

I go to change out the spark plugs, and I notice a bit of oil in the #1 spark plug well. So I cancel the plug change and put the coil pack back in figuring I need to get a valve cover before I bother changing plugs. I go to start the car again and drive home and at first it runs good and fine, then about a block or 2 it starts to do a misfire.. less at first, then progressively gets worse and worse. Trying to get the POS home, I run it while misfiring. Now the car wont even restart.

I get it to a safe location, and start digging into it with the help of a friend.

I cant get the thing to stop flooding itself. cleared cylinders, replaced plugs still misfire. Coils seems to be functioning. Do a compression check, while not the greates, its not bad at 155-150-130-155.. the 130 is suspect, but its not that bad, plus the cylinder walls are major washed down so I don't think its a head gasket issue.

Checked the timing, the upper timing gears seem to be at their marks, and the cams seem to be in the right position. haven't checked the crank gear, but I have no real evidence its off at all. chain seems taught, the tensioner seems fairly in spec, the plunger has a quarter inch travel marking discoloration, but I would assume its normal. WHat further tells me the timing is OK is that once in a whole Ill get the car to fire up and when throttled hard it will wake up and rev pretty good up around 2500-3k rpm.. it seems to have a moment of clarity like it really wants to run, but then immediately boggs out and floods.

Fuel system seems fine, had another car with its fuel system hooked up to the Altima motor, does the same thing.

injectors seem to be pulsing fine via snap on computer readout.

no sign of HG problems.

THE SPARK PLUGS KEEP CRACKING, AND ARCING. its even arced and burned a couple holes through the coil pack boots. I think this is due to the car flooding itself out. all sensors seem to be working, MAF, knock etc.. they are all communicating and seem to be within spec.

I had a breakthrough witht he MAF sensor though. Tested the maf with a known working maf, no change. but when I remove the maf all together the car will actually run and idle. It runs like a bag or s***, but it will run and I can actually put it into drive to move the car in and out of the shop. and when you rev it right up it actually revs up in the 3k range and doesn't seem to miss or anything when rpm is way high. Plug the maf back in and it wont even rev, wont idle, and wont even barely start at all.

starting to possibly think its some sort of problem with the fuse box behind the battery or possible computer/wire harness issue from the accident it was in.

Any ideas would be greatly appreciated, ways to narrow things down further. I am gonna get a fuse box and see if it helps next week, I noticed the fuse box had a burned out circuit which was very strange, but is a circuit to something trivial that has nothing to do with the engine operation.

I don't think the cats have nothing to do with this as the cats pretty much melted them selfs and blew out the broken exhaust from being run whle flooded so much. literally nothing inside the precat, the flex pipe melted and disconnected itself so you can see up the precat, and its empty, the guts of the precat basically ozzed out on the floor. I don't think it ate the precat guts because compression check and all that was done after it blew out the cat. no evidence that it sucked in the cat.


so now the car is at the point where sensors seem to all check out aside from maf, new maf doesn't change anything, old maf seems to work, but wont run with a maf. car will hold a s*** idle without maf, compression is good, still.... floods itself out.

[vostok]

Oh also, the car throws no real codes at all, aside from random misfire.

[vostok]

so we have been noticing a lot of bad ground wires throughout the car. been fixing them as we have been diagnosing.


at the point where the car will run, not good but it will run. and it seems to run best with the maf installed once again.. (hmm bad grounds?)


I have a theory, that the grounds were the original problem. now they are fixed the car runs but right now, it has no cat anymore, running with just the exhaust manifold with no backpressure, there is burned pinholes in the coil boots... the bosch plugs that we threw in because they were cheap have been through hell and back. did I mention bosch plugs? yes.... gonna try ngks now that the grounds were fixed. I have a feeling that the original problem with the car was some bad burned out grounds, then ripping it apart created more problems (cat, coils arcing, using bosch cheapo plugs)

only used bosch because the original replacement ngks got roasted int he big misfire debacle

WIsh me luck, going to attempt to put it all back together.

don't want to spend much money on this thing, gonna get ngks, jerry rig the coils and cover the burn holes, maybe clean all the black soot fromt he intake and give it a whirl....