transmission related to stalling...

[gniknave]

It just gets weirder and weirder with my Q. A month ago I was about ready to junk it or sell it for $500, even was about to part it out. Yet little by little it's bringing itself back to life again and now is running better than it has in the 6 months I've had it.

On to the question. Some may know I've had stalling problems before, as well as a slipping transmission. Well after replacing the fuel pump, FPCU, and MAF, the stalling went from consistent to intermittent. Though it went to intermittent, I could always create the problem by just coming to a sudden stop -- that's when it would always stall. It would also do so in the mornings when cold (it would studder first).

Well two days ago I had a transmission pan drop done and a filter replacement done hoping to get the car to at least shift better. Well I got more than that. The car no longer stalls -- not even intermittently, I can't create the problem no matter how hard I try.

OKOK, the question: Is there something in the transmission that would have caused the car to stall? Like a sensor or something that may have been dirty due to dirty fluid? I'm trying to figure this one out for future reference.

The transmission now shifts beautifly, no stalling, no rough idle, no buzzing from the trunk, Bose works, car has plenty of power, power steering works great (belt was loose), all this solved in the past 1.5 months....after I almost junked the thing. I guess it wants to live???

[maxnix]

Expert TLC is necessary for used cars, especially high performance luxury cars. Moreso for abused cars (deferred maintenance), which all used cars are. It is just the matter of degree of neglect that distinguishes them.

Efforts of true car care are well rewarded.

[3rd Q]

Evan,Sounds weird but I too had a "surging idle kinda wants to stall on a cold start-up " thing happening. Frustrated the **** out of me until I had the trans shop that did my re-build check it out. Found it to be a partially blocked trans cooler line in the radiator. Put on an external Tru-Cool trans cooler and the problem totally disappeared .

[96Qowner]

This post got me thinking. There are a number of people with unresolved issues that would seem to be caused by fuel delivery/regulation problems. Wes's recent idle problem, for instance, as well as several others I remember from searching archives - things that appeared just to go unsolved. But this post reminded me of some of Dennis's posts, discussing transmission temperature and the way TCU/ECUs react to it.

Is it possbile that high transmission temps cause dramatic changes in engine tuning through the TCU and ECU? See what I'm getting at? Could it be every bit as dramatic as sensor readings from the MAF, for instance? Maybe a surging transmission temp from a blocked cooler or clogged filter makes the engine all flaky.

Here's an old thread I found:

http://nicoclub.com/zerothread?id=28561
Modified by 96Qowner at 8:38 AM 1/17/2006

[gniknave]

This post got me thinking. There are a number of people with unresolved issues that would seem to be caused by fuel delivery/regulation problems. Wes's recent idle problem, for instance, as well as several others I remember from searching archives - things that appeared just to go unsolved. But this post reminded me of some of Dennis's posts, discussing transmission temperature and the way TCU/ECUs react to it.

Is it possbile that high transmission temps cause dramatic changes in engine tuning through the TCU and ECU? See what I'm getting at? Could it be every bit as dramatic as sensor readings from the MAF, for instance? Maybe a surging transmission temp from a blocked cooler or clogged filter makes the engine all flaky.

Here's an old thread I found:

http://nicoclub.com/zerothread?id=28561

I was having similar thoughts. I was VERY surprised when the stalling ended because that wasn't a result I was expecting from a simple pan drop. I too have been thinking this is what Wes' idling problem is since I did it. Maybe it's time to add this to the Q45.org tech help section?

[3rd Q]

What alerted me to the possibility of a trans related problem was a troubleshooting post on infinitihelp.com. I initially suspected a fast idle cam issue, etc.

[autotech43]

We've seen quite a few of the older Q's with the stalling concern, more often when the vehicle is cold or either when braking hard. We have seen the fluid level being low, therefore the torque converter will lock up and stall the engine. Fluid level will rise when reaching operating temperature and that concern goes away. Torque converter has to have fluid pressure to unlock. Some folks dont consider just how much a fluid of any type will rise and fall relating to temperature (degrees).

[gniknave]

We've seen quite a few of the older Q's with the stalling concern, more often when the vehicle is cold or either when braking hard. We have seen the fluid level being low, therefore the torque converter will lock up and stall the engine. Fluid level will rise when reaching operating temperature and that concern goes away. Torque converter has to have fluid pressure to unlock. Some folks dont consider just how much a fluid of any type will rise and fall relating to temperature (degrees).

Damn if that doesn't explain what was going on. When I didn't warm up the car (when in a hurry), the car would stall and studder like crazy. When warmed up, it would stall intermittently. When I did the pan drop and flush, the fluid was definitely low. It's nice to single the problem out now. :::added to my notes section:::

[in_awe_of_Q45's]

this site and Q45.org are such a fun place to spend hours and hours. thanks to all who contribute.

[Ozzie]

I also have this problem... Hope this is the solution! Thanks guys! =)

[brin146]

Same here. Engine stalls when first started after sitting for5 plus hours. Have planned on changing trans. fluid and filter due to mileage (145800) and shifting symtoms and i hope this fixes stalling too. Thanks!!

[prem]

I too have had the stalling issue for a while now and have not been able to take it in due to financial hardship. Yesterday, my 90 q45 (92,000 miles) would not rev over 2000 rpms when in gear. It revs fine in nuetral and park. This is the most relevent thread i have found to my previous issues with stalling and wonder if this a continuation of the same problem or something all together different. I'll keep searching and any input is greatly appriciated.

[squeefoo]

I Yesterday, my 90 q45 (92,000 miles) would not rev over 2000 rpms when in gear. It revs fine in nuetral and park.

Sounds like a bad MAF sensor connector, try wiggling the connector while it's running to see if that's it. You can clean the connector pins (male and female sides) and add a little silicone grease to the pins. Search this forum for maf cleaning for more than you want to know.... It would be a good time to clean out the throttle body too, since it really runs like crap when it's dirty too.

[prem]

i just got back from vacation and did some other research before cleaning the MAF. i cleaned the MAF. with more research i check my fuel pump control unit (see zerothread?id=18148) the standard "E" pin in the picture was fried, but on the blue relay, what looked to a be a seperate black wire was completley melted and had the wire exposed all as far back as i could trace the wire. The funny thing is, without doing the control unit bypass, i took it for a test drive and my car is running better, but i am afraid to drive it too far due to the fuel pump problem. I'm gonna try the bypass tomorrow, but if its running fine despite the fried wire, maybe i should just let it be and order a new fuel pump and control unit after christmas. I didn't try to drive it before i cleaned the MAF so i don't even know if the cleaning helped the problem, or it just wasn't acting up because it sat so long....not really sure what to do....any imput is appriciated