neubie needs help

[nodar37]

:icesangel Any ideas? New to site & have 2 questions. I have a 93Q with117000 miles. At mild acceleration about 40mph i get a shimmy in the transmission. If I accelerate more agressively it stops. If I let up on the gas it stops. Are there sensors adjusting the shifting. This is not a new problems (80m miles)but it seems to be getting a little worse. The dealer can't seem to identify the problem.

Second problem.. When I start the car the blowers of the heater/a-c go on automatically & I can't tuen it off. I've had to pull the fuses. I recently had the valve seals redone & the mechanic may have mis connected. Since I drive all over the country, it's not a question fo taking it back to the dealer.

Sorry this is so long. I love the site and will apreciate any help.

[Q451990]

The fan on the A/C at full blast sounds like a bad amplifier (resistor pack). Call Joe at Infiniti of Scottsdale, or someone here can advise - but that's the symptom I've heard before.

The bucking at 40MPH sounds more like a problem with your knock sensors. Mine did the same thing, and it turned out to be a bad harness. When the ECU detects bad detonation sensors, it goes into a "protect" mode and retards the timing advance as if you're running 87 octane. You can check the ECU codes yourself with the procedure in the service manual - or have someone read the codes. Dirty injectors, plenum, TB, etc. can make the problem even worse...

Heath

[nodar37]

Thank you for the reply. The knock sensors & harness were replaced at 40,000 miles and it was happening before & after.I've seen posts regarding the transmission mount (s). Could this be related to the problem.

[PalmerWMD]

moved to infinit mechanical section

[nodar37]

??????????????

[Q451990]

I've seen posts regarding the transmission mount (s). Could this be related to the problem.

I wouldn't rule them out - but typically they show up more like a vibration under your seat (that's where the crossmember bolts on). How long since your last injector flush? An underpowered engine (partially clogged injectors) can cause all sorts of problems. Actually, I had my injectors flushed and knock sensor harness replaced at the same time, so who knows which one fixed it.

Also, I wouldn't assume that something that was replaced 77,000 miles ago (or even 40,000) is still working. One minor overheat and the sensors can crack. I think checking the ECU codes and getting a power balance test will tell you a lot.

Heath

[Q45tech]

Depending on the exact angles [different cars are different] the rear transmission mount may be stressed faster.........have seen them sag again after a year or so...........failure to reposition the dive shaft center bushing [number of washers]and bad motor mounts.

[nodar37]

TO:Q451990. NO VIBE UDER SEAT. STP INJECTOR CLEANING EVERY 4-6 MONTHS. THE LAST TIME I NEEDED THE SENSORS & HARNESS REPLACED, THE CAR EXHAUST SMOKED BLACK UNDER ACCELERATION & EVENTUALLY WOULDN'T START AT ALL. NO INDICATIONS OF THIS. THANKS FOR THE SUGGESTIONS.

TO:Q45TECH. YOU AND Q451990 BOTH SUGGEST THE MOUNTS MY BE OR MIGHT BE THE OR PART OF THE PROBLEM.i'LL HAVE THEM CHECKED & LET YOU KNOW. THANKS DITTO

[Q451990]

STP injector cleaner isn't the same as a pressurized rail flush! Nothing you add to the tank will take care of injector deposits like a true flush. The symptoms you describe (black exhaust under acceleration and no-start) isn't typical for knock sensors. That sounds more like the mass air flow sensor. In any case I wouldn't rule out the sensors because you don't have black smoke!

If the transmission mount hasn't been replaced there's no need to check - just have it replaced, it's sagging by now!

Heath

[maxnix]

nodar37,

Might try a search on the "caps key". There are some good posts on how to unhook it.

[Q451990]

Is this the one you're talking about



Heath