TPS/Trans issues SOLVED!

[elwesso]

If you dont know what im talking about, heres a background

zerothread?id=159658

I decided to post it here in the Q45 forum since everyone needs to take note of it!

So as a background, i bought a used TPS from PopPop hoping that would fix my issues. as it turns out that TPS was bad, however thats not the real issue. In the end, the original TPS is now on the car (the one i thought was bad) and the car is running better than it has in a while...

After going through about 4 TPS', 3 of which were bad (2 were completely shorted out, the other one the idle switch was not working) sometimes the good TPS would not work correctly, which is why i had a hard time diagnoising this...

The day before the BIG meet i was planning on attending in Nashville TN, i randomly decided to put another TPS on the car and see what would happen..... +Didnt end up taking it for a test drive since I was so angry at the car.....

The day of the meet I decided to take it for a drive, and it drives PERFECT now! What a PITA!!!

So the problem that I blame it on: Bad connection at the ECU. How is this possible? Is my harness fubarred? No, its in perfect condition. is my ECU messed up? nope, all is perfect..... This is why its important! THIS APPLIES TO ANYONE, NO MATTER IF YOU HAVE MODIFICATIONS THAT WILL ULTIMATELY KILL YOUR CAR OR IF YOU PREFER TO LEAVE YOUR CAR AS THE ENGINEERS THOUGHT IT WAS BEST.

sometimes, the edges of the harness on the ECU has a hard time seating properly.. It just so happens, the TPS is right on the edge of the harness connector, so it was likely not getting good connections.....

So as a tip: When R/R the ECU harness connector, ALWAYS make sure it goes on straight... While tigtening it, place fingers on the edges so it goes on perfectly straight as you tighten it on.

[szh]

Good recommendation, for sure!!

Z

[DrewQ45]

Wow Wes!

Can't believe that's what it turned out to be. Maybe you have a crack somewhere in plastic of your harness causing a weakness which affects seating at the ends? Have you examined it closely? You may have over-torqued it in the past.

..Drew...

[elwesso]

Wow Wes!

Can't believe that's what it turned out to be. Maybe you have a crack somewhere in plastic of your harness causing a weakness which affects seating at the ends? Have you examined it closely? You may have over-torqued it in the past.

..Drew...

I think that is very posisble. The ECU harness on my car has been removed probbaly 3-4times as many times as other ECU harness.. From checking codes, swapping ECUs and so forth...

There arent any cracks like that, but the harness doesnt seat really well on mine... i've bene using lube when i go to install...

[Meaux]

Seems I had the same poblem...Months ago,

« Re: (DAEDALUS) 2:50 PM 9/14/2005

--------------------------------------------------------------------------------

Well I went this morning and couldn't get the problem to show up, so I thought before I get into ohming all these dang wires, I'll give it the old wiggle test. I wiggled everything under the hood. No cigar. When I wiggled the harness to the ECM the problem came back. Checked the code and got a 21. Took the harness off and found a crack in the female side near the bolt. Superglued the crack shut, reinstalled and wiggle wiggle, the problem didn't come back. Got the 5-5 code and put the ECM back in it's place. Been fine for the last few hours.

I do hear an exhaust leak right under the drivers door, just to make my day...

Puttin on the ornament covers, and drive it...If I don't have a problem in the next month...I reckon that was it...

Thanks......

Hey Wes, Did your high idle problem go away? Mine did...

--------------------------------------------------------------------------------

94 Q45, 92 Porsche 968, 72 Porsche 911, 98 Honda Civic, 89 Maxima SE, 85 F150 w/ 95 5.0Lazy Bum who lives off his wife........

[rsiwicki]

I had the same problem also....car would start up fine and run fine for the first 5 minutes and then all of a sudden as soon as you came to a stop or let the rpms drop below 1,500rpms the car would instantly shut off. I thought I had some how blown the engine or it was something to do with Robert's ECU. Turns out that while I had thought that I fully tightened the ECU connector bolt, I had not and needed 1 more full revolution and then it was on there and would not tighten anymore. I could not believe that while I thought the ECU was on there good and snug, it still needed the one more full turn to make everything work correctly. I still can't believe it was that sensitive to only 1 full turn of the bolt.

[96Qowner]

Maybe a good spot for some Stabilant 22 also, as per texasoil?

https://www.micro-tools.com/store/mainframe2.aspx

(Under Deoxidiser & Contact Cleaners)

[elwesso]

thatd be good too, itd take however to do all 96 pins on the ECU though... id prefer of osmething thats more of a "spray on" ..

About everything is good if it can be sprayed on, except tans.

[maxnix]

So connectors cannot be connected crookedly or seated improperly and be expected to function? I'll remember that!

[sijoko]

One thing that I do when disconnecting the ECU is to first remove it from its location and then disconnect the harness. It takes a bit more time but it does minimize potential problems with the connector.

Otherwise, you will end up removing and installing the connector at a severe angle.

I don't know how you removed the connector, Wes. I am just putting this out as a FYI.

[elwesso]

One thing that I do when disconnecting the ECU is to first remove it from its location and then disconnect the harness. It takes a bit more time but it does minimize potential problems with the connector.

Otherwise, you will end up removing and installing the connector at a severe angle.

I don't know how you removed the connector, Wes. I am just putting this out as a FYI.

I was never able to remove the ECU without removing the connector? care to share?

[texasoil]

I STONGLY recomend 'Stabilant 22' for all critical electrical connections on Infiniti's. It is MAGIC.

Even 'brand new' connector conductivity is improved.

[Meaux]

OK, I'll bite...

Where can I get this "magic" stuff?

[elwesso]

OK, I'll bite...

Where can I get this "magic" stuff?

Maybe a good spot for some Stabilant 22 also, as per texasoil?

https://www.micro-tools.com/store/mainframe2.aspx

(Under Deoxidiser & Contact Cleaners)

OK, I'll bite...

Where can I get this "magic" stuff?

[Meaux]

Jeeze Wes, I'm more blind than I thought!

Holy Crap! They are sure proud of that stuff!

Maybe I'll just use the DeOxit I have in a spray can...

[elwesso]

Im going to send keith an email, he said something about a group buy

[Meaux]

Cool, I'm interested...

[ddrumman]

Im going to send keith an email, he said something about a group buy

I would be interested as well.

D.

[BlackBirdVQ]

I think my OE TPS sensor might be taking a dump now also.... I havent changed that durring my engine rebuild, but I have a new MAF, 02s, Knocks, etc....

Last nite the car hesitated off the line really bad- felt like it didn't respond to my throttle input for a second till I let off actually and reapplied the gas pedal.

Its eighter the TPS or MAF connector- which I wiggled but nothing really changed. Trans shifts weird at times and its always slow to respond to my gas pedal applications- aka downshifts. After bout 30 min of driving the check engine light comes on but I am missing the EGR temp sensor still (guy who polished my intake manifold lost it), so I am not sure if the EGR sensor is causing that or there is something else stored in the ECU. Hooking the consult up to the car with the light OFF (goes off after you restart the car) doesn't show up any codes.

It kinda pisses me off as the transmission doesn't wanna respond well untill I lay down on the hammer and even then under wide open throttle it doesn't seem to pull as hard as when I let off the gas a lil bit- to like 75% throttle and it moves better....

I have been driving the car for approx 500 miles since I got the engine togheter to make sure I do not have any oil leaks or coolant burning issues. I switched to Mobil 1 and my rear main seal started to leak

BTW can someone measure their DIP STICK and tell me how long the stocker is ? I need to make a new dipstick out of something cause my stocker is missing.....