Is this my turn to pop a fuel pump?

A Q45 forum / Cima forum for the President of Infiniti's lineup. Brought to you by Infiniti Parts USA, your OEM source for Q45 parts!
tmak26b
Posts: 101
Joined: Mon Jun 23, 2008 6:23 pm
Car: 95 Q Boat

Post

I was driving to get two new tires installed. today. On the way to the store on the highway, I noticed a slight hesitation whenever I pulled uphill. When I pulled off the highway, I can feel the car was down on power and it would occasionally backfire. NO matter how hard I hit the gas, the car seems to run around 3000RPM. I proceeded to drive all the way to the store. I didn't think much of it and just went into the store (It happened once when I lend the car to my friend). When I came back out, the car simply refused to start. At the beginning, the car would TRY to run. Yet whenever I hit the gas, the car would just die. If I just turn it on and leave it running, it will struggle to run about 1 minute before it dies. After doing that for 10 minutes, I decided to call for help. Before the help arrived, I tried to crank it once more. Now the car doesn't even want to turn over and I honestly don't hear or smell any fuel, I assume the pump is done?

tx


User avatar
Infinitiguy19
Posts: 7787
Joined: Sat Dec 22, 2007 4:58 pm
Car: 1993 Infiniti Q45 188580 Miles
1994 Infiniti Q45a 240000 Miles

Post

I think so, As may be the Fuel Pump Control Unit AKA FPCU. I have one just need to see if it works or not. (haven't installed it so it wasn't grounded but I will ground it and let you know if your interested)

tmak26b
Posts: 101
Joined: Mon Jun 23, 2008 6:23 pm
Car: 95 Q Boat

Post

By the way, no noise from the pump before. What is the best way to see if it is the computer or the pump? Jump a fuse to bypass the computer?

How much is that thing anyway? THanks

User avatar
Infinitiguy19
Posts: 7787
Joined: Sat Dec 22, 2007 4:58 pm
Car: 1993 Infiniti Q45 188580 Miles
1994 Infiniti Q45a 240000 Miles

Post

If you had no noise then look elsewhere.

But if you thought the buzzing was normal then it must be it.

Just ground it by doing this:

And brand new is $700 I think but make an offer or I would say $80 shipped is fair.

tmak26b
Posts: 101
Joined: Mon Jun 23, 2008 6:23 pm
Car: 95 Q Boat

Post

In the picture, there is no ground to that clip? I assume I just clip the other side to some panels?

Thanks for the tip, I will just ground the thing first and see if the car starts. If it is, then I know the pump is okay and the computer isnt

User avatar
Infinitiguy19
Posts: 7787
Joined: Sat Dec 22, 2007 4:58 pm
Car: 1993 Infiniti Q45 188580 Miles
1994 Infiniti Q45a 240000 Miles

Post

Exactly, Good luck

maxnix
Posts: 22627
Joined: Mon Jul 22, 2002 8:11 pm
Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45

Post

ppastos wrote:If you had no noise then look elsewhere.
Not true! Pumps have failed while still quiet.

One must always check the fuel pressure at idle and WOT.

User avatar
Infinitiguy19
Posts: 7787
Joined: Sat Dec 22, 2007 4:58 pm
Car: 1993 Infiniti Q45 188580 Miles
1994 Infiniti Q45a 240000 Miles

Post

Wow Well I didn't know that, That's scary.

maxnix
Posts: 22627
Joined: Mon Jul 22, 2002 8:11 pm
Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45

Post

Few and far between fail that way, but it has occurred.

And no way to standardize on "noisey" between members on the internet, most of whom have never met.

User avatar
slybydesignq45t
Posts: 356
Joined: Wed Jun 04, 2008 9:27 am
Car: City Bus

Post

I just wanted to throw this out there. I had the same problem when I first purchased my car. It would not give me power then it just died on idle. It did this several times. So I let the car sit for about 3 days till I had time to look at the problem. I took apart the MAF unit, and cleaned the heck out of it. After cleaning the MAF and connectors I then started the car, for about three days of driving the car seemed to improve. Now it starts right up and has a lot of power to throw around. I know the FP is a demon to our cars, but cleaning the MAF is something I would consider as well. Because from what I have learned they MAF/FP shear the same symptoms.

jimbyjimb
Posts: 492
Joined: Thu Apr 03, 2008 8:57 pm
Car: 1992 Infiniti Q45

Post

Use the K.I.S.S. principal. Start small and work to bigger things. Clean MAF and CAS connections with special care paid to the wires going into the MAF connection. The wires come loose and fall out the back of the connector. Check fuel pressure, filter. If you still don't have answers time for spark tests and injector ohmage. Since it won't start it's likely a sensor or the pump, but there could be more than one problem. Good luck.

tmak26b
Posts: 101
Joined: Mon Jun 23, 2008 6:23 pm
Car: 95 Q Boat

Post

It turns out to be the fuel pump controller. As expected, the unit blew out and left a nice crater on the circuit board....


Return to “Q45 Forum / Cima Forum”