Couple of problems with the Q

[KillerAngel]

Hey guys, got a couple of problems with my Q, just wanted you alls input. Its a 95 Q45T with TC and Wes's ECU (which I love). Only has 104k miles on it, but its started to have problems. Alternator went bad a few months ago, fixed it, no big. I also lent it to my friend a while back who managed to fill it with 86 and drive it for 4 highway hrs, and "forget" to tell me when he realized what he did. No noticeable problems resulted though... so far...

What I need help with are common problems resulting in a high cold idle (1.5-1.25k at start, 750 at operating temp). It also seems to be slightly struggling to start lately. Might just be the cold weather, but the high idle has been happening for a while now. I looked around but couldn't find anything that might be causing it.

My other, more important, question has to do with the transmission. It has had a slight hard shift problem from 1-2 for a long while now, but nothing major or very noticeable. Well its definitely getting pretty noticeable now, as well as some late shift problems. I also do a lot of highway driving (3hrs from school to home), and every once in a while I can feel the car vibrate and jerk (happens for maybe 5 seconds, and occurs maybe 2-3 times per 3hr trip). This happened once at a street light, the car was very noticeably vibrating. Stuck it in neutral, it went away. Put it back in drive and it was fine again. The vibrating all started maybe 2 weeks ago. Anyone experienced something like this? I cant tell if maybe its a bad torque converter or the whole transmission going bad, or what... I dont know much about Q internals, so any help is appreciated.

Thanks...

[96Qowner]

This vibrating/jerking - could it be described as "bucking"? On your long drives, does it quietly vibrate, or does it jerk once or twice and quit?

If it's sharp and short, like the engine missed a beat or two, it's probably your MAF.

Otherwise, I'd do a transmission flush and see what happens. When was your last flush?

[pito11213]

Your cold start rpm's sound normal actually. Idles briefly at about 1500 then drops down as the car gets to proper operating temp.

As far as the gas goes, if you arent getting engine knock then be happy. These cars can run on cheap gas, just not well.

What color is the transmission fluid on the dipstick?? It should look pink. Does it smell burnt? Is it bubbly?

Vibrating in the car could go back to your gasoline mishap. I would go with a full tank of 93 plus a bottle of techron for now, if they problem persist, go with a BG44k bottle and take if from there.

[Haitian_King]

I just got over a transmission scare with my Q. Most of the time it shoots off the line like rocket since I put my TCU in and got the trans flushed. But sometimes it doesn't go "as fast". Quick enough, but slow enough for me to feel it. I thought that my whole trans was bad and I was scared/depressed for a couple of weeks. Now, i've gotten the problem down to something more bearable and easier to deal with.

As far as the rough idle/vibrating at a red light goes, check your injectors. I had a bad injector and the car idled really rough. Like a serious up and down idle. Replaced the injector and now it idles super smooth. I occasionally get a slight "purr" or rough spot, but I think that can be solved with a can of BG 44K.

Keep us posted.

[1990QOwner]

The rough idle is probably a result from the lower octane fuel and will most likely go away with some sort of fuel treatment or some sort of injector cleaner.

[Q45man1]

I had the same problem few days ago. The idle speed is high during cold start.I throughly cleaned out my TB, replaced my MAF with my last spare. I might have to buy a new MAF since I'll be keeping this car for a long time. You also have to look into the idle air control valve (IAC), dirt accumulates in there. If requires cleaning you have to disassemble the part.

Good luck.

[KillerAngel]

Thanks guys, big help so far...

Just had the redlight vibration happen again tonight, not a fun feeling.

Haitian King: I dont think it would be a bad injector because it doesnt happen all the time. Only about every hundred miles I guess (getting more frequent I think)... Am I wrong in assuming this?

Pito: The high idle sounds normal? Its never happened to me before until just a few weeks ago... Also, I always fill it with 93, and the second I called him to double check what gas he put in, I went and filled it up and kept filling it after every 1/2 tank.

96QOwner: its kinda both. Short jerks on the highway, hard vibration at stop. Is there a way I can test my MAF performance?

Tomorrow, if I get a chance, i'll check the transmission fluid. Come to think about, I havnt flushed it in a while. How often do you guys usually flush these things?And over TG break i'll stop by the old Auto Repair shop I used to work at and get a BG kit and maybe flush the transmission... Hopefully it makes it home :P

Thanks again for the help guys. Keep it coming if possible...

[maxnix]

Tomorrow, if I get a chance, i'll check the transmission fluid. Come to think about, I havnt flushed it in a while. How often do you guys usually flush these things?

And over TG break i'll stop by the old Auto Repair shop I used to work at and get a BG kit and maybe flush the transmission... Hopefully it makes it home :P

About every 15K - 25K.

A BG ATF exchange machine is about $5K. Far better to pay the $100 and let them do it for you.

[Haitian_King]

I hope you figure it out.

Have the flush done. I had one done this past weekend and I'm a believer now. So are all of the people I dusted.

Have you tried the BG 44K in the gas tank?

Just to be sure, ohm the injectors. It's better to find out that they're not the cause of the problem early, rather than finding out later.

[pito11213]

Maybe I'm wrong, but as it gets colder outside, the start up idle goes up higher than it would if it was warm outside. I would go ahead and do the MAF clean anyway, it wont hurt unless done wrong.

Check your fluids asap and do the smell test.

[elwesso]

Just to clarify some things

1250 idle at cold is NORMAL... Dont worry about it.

hard start could be a fuel filter (when was the last time it was replaced?) or the fuel pump itself. Can you hear a buzzing sound behind the back seat?

I think you're starting to see the first signs of a bad fuel pump, check fuel pressure...

[KillerAngel]

Well I have noticed an intermittent buzzing sound at startup, but it was like.... months ago. Hasnt happened recently. My first thought was fuel pump, but it sounded like it was coming out of the speakers behind the back seat and it only lasted a few min... I just played it off to bad wiring thats plagued the car since my dad first bought it... Elwesso, now you have me worried... Never checked fuel pressure before in a EFI car. Point me in the right direction?

Never have personally replaced the fuel filter, but ive only had it for about 3 years now (30k miles-ish). I dunno about my dad but he was always spot on about maintenence. Its been about 20-25k since the last transmission flush so thats due anyway...

Haitian: I'll get the BG done when I get home this weekend... No time till then...If I may ask, whats the standard resistance of the fuel injectors?

[Haitian_King]

Proper ohm resistance is 10-14 ohms. There's a picture floating around the board that Mike made detailing the injector plug and the pins that should be tested. I think anything below 10 and above 14 = time for a new injector.

[1990QOwner]

Well I have noticed an intermittent buzzing sound at startup, but it was like.... months ago. Hasnt happened recently. My first thought was fuel pump, but it sounded like it was coming out of the speakers behind the back seat and it only lasted a few min... I just played it off to bad wiring thats plagued the car since my dad first bought it... Elwesso, now you have me worried... Never checked fuel pressure before in a EFI car. Point me in the right direction?

Never have personally replaced the fuel filter, but ive only had it for about 3 years now (30k miles-ish).

The fuel pump is located behind the back seat right under the back speakers. It it is or was buzzing than I would get it checked out.

The fuel filter is under the hood on the passenger side.

I think you can get a new fuel filter for less than $20 and it is easy to change.

There are several threads on checking the fuel pressure. Just go to your local auto parts store and get a pressure gauge and hook it up to the fuel line AFTER the fuel filter. When I did mine after I replaced the fuel pump than it was at 60 PSI.

[maxnix]

1.) I just played it off to bad wiring thats plagued the car since my dad first bought it...

2.) Never have personally replaced the fuel filter, but ive only had it for about 3 years now (30k miles-ish).

1.) Can't recall an Infiniti on this board that ever had "bad wiring" for m the factory.

2.) Fuel and air filters should be cahnged annually. You, sir, are abusing your automobile.

RTFSM, then all the posts by Q45tech, or kiss you car goodbye.

[KillerAngel]

Maxnix: Now you can... my dad had to take it in to the dealership at least 3 times to get bits of the electrical squared away... And those are the times I remember. It was mostly sound system stuff, hence the thought: bad rear speakers.And yes I guess I am abusing it... Cute subject line btw... I like it

Thanks again for all the help guys... I'll get this thing squared away ASAP...

I think subconsciously I'm trying to kill my car so I have an excuse to take out the VH45 and put it in something smaller ...... You all hate me now im sure

[maxnix]

No user or 3rd party "modifications"? That is when G50 electronics go bad.

The VH45DE even today is still an advanced engine with few peers when it comes to overdesign and qulaity of build. So many young newbies just don't understand waht they have at a bargain price. Ferrari would have killed for this engine twenty years ago.

[KillerAngel]

No user or 3rd party mods. Its the factory Bose system and has never been touched by me. Only mod to the car is Elwesso's ECU.

And I know exactly how amazing the VH45 is... Which is why I want to put it into something... smaller...

[KillerAngel]

Got a fuel pump on the way... Its definitly getting loud, I can hear it now from the driver's seat. Readin on the site, people say to replace the fuel pump control module as well because a bad pump can hurt the module, and a hurt module will kill the new pump. I can open it up and re-solder the "melted" connections if there are any, I'd just like some advice from you guys before I go and melt a new fuel pump. My old one isnt dead, but its defininitly not doing well. Ive also done the bad of running below the 1/4 tank line quite frequently. Car killer I am...

Also gettin the transmission flushed soon too.

I was gona clean the MAF anyway, so I read the how to article. It said to spray the electrical cleaner on either side of the sensor, but not on the sensor itself... "Allow the spray of the aerosol can to clean the device, but never touch the sensor itself."How is it cleaning it if its not touching it? I dont get it. (Please forgive a carb guy in the world of voodoo electronics)

[Haitian_King]

From what I know about MAF cleaning is that the aerosol cleaner spray can contact the sensor. But don't concentrate the spray on the sensor to the point it starts to puddle/drip. You can't. Don't touch it with a finger, Q-Tip, nothing.

[elwesso]

Yeah, just shoot it with cleaner, dont touch the element.

[Haitian_King]

Haha! I'm on a roll!

[KillerAngel]

haha okay... thats what I thought, i was just checkin...

Any advice on the FPCM?

[maxnix]

haha okay... thats what I thought, i was just checkin...

Any advice on the FPCM?

MAF cleaning is highly overrated and usuallly not necesaryu unless the unit has been abused by aftermarket filters or not changing the stock filter often enough. MAF connectors prior to the final configuration started in late 1994 can be problematic and a much more likely culprit for rough running.

FPCM needs to be examined, repaired if necessary, then monitored. Some faults are virtually undetectable, even by Q45tech. Always have a believed known good spare.

[Haitian_King]

I couldn't begin to tell you.

I spent a couple of hours poring through Fuel Pump threads and reading tangalora's memoirs about her FP experiences. I came out extremely paranoid. I thought the sound of the fuel pump (priming?) before I started the car was a signal of imminent doom. That's not the case is it? If the pump is audile while the engine is on, that's when it's bad?

I turned my radio off and listened while driving but I couldn't hear anything. I'm hoping that I don't have to worry about that particular problem for a while.

[jmorasch]

I noticed severe idle changes as winter weather comes with our first Q....Im here in k.c.k. and the weather changes from one extream to the next in a matter of 24hrs. Both Qs do this now...when the temp. drops Far as the transmission goes I was real close to getting another transmission for the first Q until I got the total estimate needless to say the trannys are tempermental so to speak,least thats the way I see it.this is my opinion through the years of owning the Q. I never changed the transmission in the first one,and the 2nd Q shifts the same way but not at the exact same rpms. theres no vibration though. the first Q,the misses Q had about 140k on it when we got it,its at 193k now and still going strong.thank the lord for the guys here at NICO,theyve never given me a bad suggestion and now Ive learned not to race W/ a large quanity of weed in the console too

[Haitian_King]

My idle temps have been good.

What I've been noticing is, when it gets colder, my trans does strange things.

I don't drive hard until the car is warmed up, but sometimes, the trans acts perfect. Like tonight, the trans was perfectly mated to the accelerator. I felt like I could accelerate forever.

Then, there are times when the trans will not harness all of the power, and then "kick" in and make the car jerk.

It's a real pain, these two situations happened today. I went to the airport and it wasn't shifting perfectly. This was at 6 PM. Then, I went out again at 11. The trans was so excellent. I wanted to just floor it.

I hope Keith can fix it.

Jmorasch, how's the heat problem in your wife's Q? Is it resolved?