'91 Q45 fuel pump and FCM problems

[blakester3]

Thank God I found this forum...just had work done on the fuel pump..mechanic said pump was OK but needed new ground...where can i find articles etc on how to deal with fuel pump and other problems on this topic?..thanks...Blake

[Jesda]

Q45.org and the search button in the upper right.

New 'ground' I assume means new FPCU? Might have one for sale if thats what you mean.

[96Qowner]

I got this thread on a search for "FPCU wire" in post bodies:

zerothread?id=36948

And there's Q451990's link that doesn't work:

zerothread?id=36156

[Q451990]

The pump will pull too much current as it gets old. Your mechanic probably checked the pump and found that it was getting voltage on one terminal (+) but not ground on the other - bringing on his recommendation of "it needs a new ground"

The difference between your Q and most other cars, is that the fuel pump runs at three different speeds. Low at idle, medium under light acceleration, and high under heavy acceleration. The ECU controls this via the fuel pump control module.

In your case, the pump probably got old (over 80K typically) and pulled too much current. This burned out the controller. The bottom line is that you need a new pump, and new controller.

Did you hear a humming noise from behind the back seat at idle, especially when the tank is 1/2 full or less?

Heath

[blakester3]

Hi Jesda..many thanks for the reply..you are right..i need a relacement Fuel pump control unit...also going to need a new or replacement fuel pump..the car is running now but this is likely to be short lived until i replace these 2 units...how much for the controller?...thanks..Blake

[blakester3]

Many thanks..both these articles were very useful...blake

[blakester3]

You guys are fantastic..many many thanks for the helpful advice..now i need to find a Fuel pump controller and a fuel pump....P.S. I live on the far East Coast of Canada in Halifax, Nova Scotia...this is a beautiful part of the world but only a handful of Q45's exist here...the nearest junkyards with possible Q45 parts is over 1500 miles away...The local Infinity dealer has provided excellent service but his prices are very high, both for labour and parts..The one side benefit is I rarely see another Q45 in my day to day travels...making my car very unique...thanks guys

[Jesda]

Hi Jesda..many thanks for the reply..you are right..i need a relacement Fuel pump control unit...also going to need a new or replacement fuel pump..the car is running now but this is likely to be short lived until i replace these 2 units...how much for the controller?...thanks..Blake

The item was listed here:http://cgi.ebay.com/ebaymotors...34662