Pull and inspect plugs, then check a realtime scan of the ignition timing, should be hitting about 45 degrees advanced at max rpm.

Is there any particular part of the powerband where it feels like it's lacking power or is it just missing power across the board? Can you hear any sort of miss at idle? Does it surge rpm at all or hang rpm when letting off the throttle?

 

It's is slow off the line. It revs and gets power fine. It tends to run around 3k rpm driving lessons cal road speeds. When you get on the highway and it tries to go in 5th it will rev very high. Sometimes 4 to ,4500 Rpm to try and do 60 mph. The workaround is to push it in manual and drive it in 4th which I've been doing on all driving above about 40mph. We can check the plugs but this mechanic has done a bunch of these swaps and he is stumped. Ignition timing is 40 to 45 at 5600 rpm

 

There is a ground wire on the front of the engine, on the timing chain cover, right at the center top of the cover. You will see TWO wires landed on bolts next to each other, one of them is the TCM ground, I would disconnect the battery, remove those two bolts, use a wire brush to clean up the lug, the bolt, and the timing chain cover mating surface, apply a very thin layer of electrical anti-oxidation grease and bolt it back on.

Also a larger gauge jumper wire from the right side (passenger) of the timing chain cover that lands on the chassis directly below the coolant reservoir on a 2-hole lug, same thing unbolt, wire brush, deox, bolt back together.

Lastly the negative battery wire itself, clean both ends it's just a short jumper that bolts the battery negative to the chassis on a 2-hole lug.

I'm thinking something with the electrical system has a tiny bit of resistance that's screwing up the TCM causing the high rpm shift.

 

I will run this by him Monday. He is wondering if the catalytic converter could do be the issue or if he need to relearn the throttle bodies. He e was noticing a burning sulphur smell when we drove it around. I should know more monday.

 

Rotten egg smell is 100% a bad catalytic converter. This is what happens when they overheat and cook off, however they can be overheated by too much raw fuel being pumped into them due to poor fuel management, stuck injector, misfiring cylinder, etc.

Borescope the cats to see if they're melted on the element inside.

Pull and inspect plugs because that tells you what the actual conditions are inside the combustion chamber.

Check what short and long term fuel trim is on each bank, that will help diagnose fueling issues.

 

So we did these thing . Trouble accelerating still as if it's in limp mode. Feels like a plugged cat but the cat tested fine and so did the fuel pressure. No vacuum leaks. All grounds cleaned and check good. 02 and exhaust sensors were verified for air flow. Brake pedal grommets have disintegrated. We will replace those tomorrow and run a compression test if the issue persists. Any thoughts? Possible fuel injector issue.?

 

I would remove the cats and go for a drive. Loud AF with open exhaust off the headers and it will throw various O2 sensor codes that will need to be cleared but at least you'll know definitively if the cats are plugged or maybe some OTHER exhaust restriction causing a lot of back pressure.

 

The mechanics next guess was going to be to clean the fuel injectors if the replacing the grommets does not correct this. Have you seen that issue on these in the past, and has it caused similar problems? The car is at 125k miles.

 

Condition hasn't changed. Compression test showed starting with passenger bank cylinder 1 - 98 PSI, cylinder 3 100 PSI, Cylinder 5 150 PSI, Driver side cylinder bank 2 is 110 PSI, cylinder 4 is 125 PSI, cylinder 6 is 140 PSI. Valve covers need replaced. Oil intrusion on passenger bank. Based on measurements motor should be replaced, but when the vehicle was scanned with an AUTEL to erase the codes, we found no ignition coil codes, no mass air flow codes, and other sensors that were unplugged to get access to the ignition coils so we can do a compression test were no found either. The only codes were the throttle body. The Vehicle scan cycles 4 or 5 times and says no response before finally giving codes. It take much longer to scan than it should. 5 minutes at least. We are suspecting this to be a bad computer. Any thoughts? We should have had codes for the coil failures at least.

 

We tried another computer and it's not that either. The mechanic is stumped at the moment. No codes, and it's like it's stuck in limp mode. The clock spring does need replaced, but we can't imagine that would cause this. Any thoughts?

 

Probably need all the major systems recalibrated since things were unplugged. Anytime you unplug stuff like the throttle body you need to recalibrate it. Steps are listed in the FSM section EC - Engine Controls at the start of the document under "basic service procedures".

As for those compression numbers... yeah that engine sounds like it's cooked, MASSIVE difference in compression between the highest and lowest cylinders.

Here's a link to the FSM for the recalibrations.

https://www.nicoclub.com/infiniti-service-manuals

 

hey I have a question my Tcm went out on my 2006 g35 base model and I bought one off of eBay a refurbished RE5R05A for it but does it need to be reprogrammed I was calling around to different shops and one shop said only 2008+ need to be reprogrammed and I called another shop and they said it needs to be reprogrammed so who do I belive becuase the guy that said only 2008+ need reprogrammed is charging 400 the other shop that said it does need to be reprogrammed is charging $750