1990 Q45 turns off while driving and back on

[breda43]

My 90 Q45 starts fine but will turn off and start running again.Sometimes I'll have to turn the ignition to start.It has been doing this for a while and I've ruled out the fuel pump.Is this the ignition switch possibly? 216,000mi.

[squeefoo]

Bad solder joint in the FPCU ... didn't you ask this already ??

[DrewQ45]

Bad solder joint in the FPCU ... didn't you ask this already ??

Breda,

Hate to sound like a merchant but.... I'm your man again if you need this. Got a module out of a 92' Q45. Will work with a 90'.

$60 + Ship but since I'm already shipping you a radio, I'll just throw it in the box too if you want it. Installation requires back seat and rear deck removal. Not too hard, I can explain it all if you need me to.



...Drew....

[elwesso]

or you can zip-tie it out of the way like I did for a whlie...

[DrewQ45]

Proper grounding Wes! Don't tell em all your dirty lil secrets.

[breda43]

Wouldn't a bad solder joint in the FPCU just completly shut it down?

[squeefoo]

Wouldn't a bad solder joint in the FPCU just completly shut it down?

I had (I'm sure) the exact problem almost 8 years ago.

It would die at the damnedest times in the summer and when I let it cool off by opening the trunk it would start after about 10 - 30 mins. A couple times not at all, which cost alot since I didn't have towing on the ins. then

I looked at the FPCU connector and found a burned pin which led to the board inside, a few minutes with the solder gun fixed it.

As I found out later here at NICO the ground overheats on a bad fuel pump. If your pump is making noise it will need to be replaced since it will draw more current than the pin/solder joint can handle and melts the solder. The joint melts together when it arcs and then melts apart when it is under load (sometimes).

If you do a search under Tangalora and fuel pump in the Infiniti Mechanics section you'll find a nice write up, it might be in the articles section on top too.

[breda43]

Hey thanks ! That was a more definitve look at what is going on with my car.I'll replace the fuel pump and I did check the connections at the pins as well as taking the cover off the FPCU and looking inside for burns of any kind (none found).

[squeefoo]

...I did check the connections at the pins as well as taking the cover off the FPCU and looking inside for burns of any kind (none found).

The connector isn't always burned -I just lucked out. In the search above there is a picture of the exact pin/board connection to check. It isn't always as easy as it was for me.