'97 D90 - No power to fuel pump, why?? - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #1  
Old October 2nd, 2012, 01:41 AM
ember
Status: Offline
ember bane
Member
 
Join Date: Dec 2003
Location: roanoke, va
Posts: 118
'97 D90 - No power to fuel pump, why??

Anyone out there know why power would not be getting to the fuel pump? It's not the inertia switch, fuel pump relay, or fuse. I think the ECM is not be sending power to it due to some sensor(???).
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old October 2nd, 2012, 01:35 PM
1of40's Avatar
1of40
Status: Offline
1of40
NAS 97SW & 83 One Ten Tdi
Member
 
Join Date: Dec 2003
Location: Potomac Falls & Wintergreen, Virginia
Posts: 6,085
Registry
brake sensor?
Reply With Quote
  #3  
Old October 2nd, 2012, 01:44 PM
rijosho's Avatar
rijosho
Status: Offline
Joshua
1995 Black ST - Rhinolined edition
Research Assistant/Eagle Eyes
 
Join Date: Apr 2009
Location: NYC
Posts: 16,557
Registry
rule out ignition switch as well.
__________________
Quote:
I am talking purely from an aesthetics standpoint.
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old October 2nd, 2012, 01:46 PM
ipgregory's Avatar
ipgregory
Status: Offline
Ian Gregory
'97 D90 ST #1008
Member
 
Join Date: Jun 2009
Location: Henderson, NV USA
Posts: 1,083
Registry
There have been a number of discussions recently around these circuits and how they work. Do a search for the longer versions.

Short version:

There is an immobilization Ďcapabilityí built into a 97 but itís not user selectable in a stock truck (no key fobs). In a nutshell the ECU has to receive a signal from a correctly Ďpairedí Alarm ECU in order to provide a ground to the fuel pump relay and activate the fuel pump. Only way you should know it exists is if there is a problem with the sync between the ECUs. This can be a bad ECU or more commonly a bad wire or connector stopping the signal making it through. Seems to happen more on D1s (same set up) than on D90s though and I doubt this is your problem.

There are circuit diagrams and other stuff in the other posts if you want to get more info and help you track it down. How do you know the relay is working for example if you have no power? Does the power come out of the relay but is not present at the pump? That would be wiring between the 2.

Brake switch will not kill the fuel pump. Just the solenoids to stop you getting it out of park, etc.

I would 1st remove all the connectors from the Engine ECU and Master Relay and make sure they are clean and dry and not corroded or bent.
Reply With Quote
  #5  
Old October 2nd, 2012, 01:47 PM
evilfij's Avatar
evilfij
Status: Offline
evilfij
I have never seen a rover in person
Member
 
Join Date: Oct 2003
Location: on the internet
Posts: 14,688
I hate GEMS, but maybe crank sensor too. Do you get the CEL to come on and go off when you first turn the key?
__________________
*not legal advice*
Reply With Quote
  #6  
Old October 2nd, 2012, 02:29 PM
ipgregory's Avatar
ipgregory
Status: Offline
Ian Gregory
'97 D90 ST #1008
Member
 
Join Date: Jun 2009
Location: Henderson, NV USA
Posts: 1,083
Registry
Easy to test the CKPS. Youíll need a helper to run the ignition key and a test lamp or probe.

Set up the test lamp/probe on the fuel pump wires somewhere in the circuit between the relay and pump. Have your helper turn the key to position II but donít try and start it.

1. Does the fuel pump circuit get power (and ground) for a few seconds and then shut off?

If the answer is yes then wait a couple of seconds and turn the key to position III and try and start the truck (donít turn it off 1st).

2. Does the fuel pump power (and ground) turn back on?

If the answer to 1 is yes then you do not have an immobilization issue (You can also verify this if the Check Engine light turns on for a few seconds and then goes off when you turn on the power. No lamp = possible immobilization or blown bulb). If the answer to 1 is no then itís not the CKPS (at least thatís not the initial fault you have). If the answer to 1 is yes and 2 is no then the ECU does not know the engine is turning and the CKPS or its wiring/connectors may be at fault.

If you have power (and ground) in the circuit but no fuel pump then move back until you lose it and the issue is somewhere between the 2. If you have power (and ground) all the way to the fuel pump connector then the issue is likely in the fuel pump itself.

HTH

Ian
Reply With Quote
  #7  
Old October 2nd, 2012, 02:56 PM
leastonce's Avatar
leastonce
Status: Offline
Jason England
D-90 White 95 SW #65
Site Team
 
Join Date: Jul 2009
Location: NYC
Posts: 6,078
Registry
roll over sensor
__________________
Quote:
Soapy water / KY jelly, etc. is is basically a must. Yes, good idea to remove trim panels - only takes 5 more minutes to do so.
Car Camping Collective founding member and Chief Executive Officer
Cat Camping Collective founding member and Chief Executive Officer
Reply With Quote
  #8  
Old October 2nd, 2012, 03:05 PM
evilfij's Avatar
evilfij
Status: Offline
evilfij
I have never seen a rover in person
Member
 
Join Date: Oct 2003
Location: on the internet
Posts: 14,688
Quote:
Originally Posted by leastonce View Post
roll over sensor
He said he checked the ineritia switch already
__________________
*not legal advice*
Reply With Quote
  #9  
Old October 3rd, 2012, 01:07 AM
ember
Status: Offline
ember bane
Member
 
Join Date: Dec 2003
Location: roanoke, va
Posts: 118
thanks so much for the helpful suggestions. As for the power to the pump, I don't get it at all, not even when I first turn the key to position II. If I take a positive lead from the battery and connect it to the pump the engine will start and run (I'm now thinking that this would rule out the ALARM ECU because it cuts the ground to the fuel pump, which means it still wouldn't work with me doing this). What would you test to rule out the ignition switch or would this already rule it out? also, the check engine light remains on while key is in position II, however I plugged up my OBD2 reader and it gives no codes. thanks again for all the advise.

------ Follow up post added October 3rd, 2012 05:14 AM ------

thanks so much for all the advise. A few things that I have checked tonight: I don't get power to the pump ever, not even when I first turn the key to position II. If I run a positive lead from the battery to the pump, it will energize and the engine will start and run (which I think means that I can eliminate the Alarm ECU, being as it cuts the ground connection and the pump still wouldn't work when applying positive juice to the it, Right??). Also, the check engine light stays on while the key is in position II. I plugged up my OBD2 reader and no codes are present. any other ideas? thanks again for all the tips.
Reply With Quote
  #10  
Old October 3rd, 2012, 01:29 AM
ipgregory's Avatar
ipgregory
Status: Offline
Ian Gregory
'97 D90 ST #1008
Member
 
Join Date: Jun 2009
Location: Henderson, NV USA
Posts: 1,083
Registry
The immobilize function affects the ground to the fuel pump relay, not the pump itself. Itís not your issue though as your CEL comes on.

Turn on the key to position II for a few seconds. Then turn it off and listen for a click from the master relay unit a few seconds later as it drops out. If it doesn't then you are probably not getting power to it. It should be OK as you can start the truck if you jumper the pump but worth a check.

Check the ignition switch as Josh suggested. Again not likely as you can start it jumpered.

Try removing the connector from the inertia switch and jumpering it to bypass it? If that works then itís a bad or open switch.

Double check all your fuses (with a meter if you have one) including the ones in the engine bay fuse box. Make sure you have power flowing across them..

Double check your connections at the master relay unit and the engine ECU.

Do a visual check of your wiring between the engine bay fuse box and all the way to the pump itself. Do a continuity test on each wire and check for ground on the power cable to check the section that goes through the chassis.

Do you have the circuit diagram for this? I posted it on one of the other threads if you donít.
Reply With Quote
  #11  
Old October 3rd, 2012, 01:39 AM
ember
Status: Offline
ember bane
Member
 
Join Date: Dec 2003
Location: roanoke, va
Posts: 118
I hear the click when turning off the ignition, so the master relay drops out and is getting power. I tested the wires leading to and coming from the inertia switch and they both have power (I guess this rules this out). I'll check the other suggestions tomorrow. thanks again.
Reply With Quote
  #12  
Old October 3rd, 2012, 02:05 AM
ipgregory's Avatar
ipgregory
Status: Offline
Ian Gregory
'97 D90 ST #1008
Member
 
Join Date: Jun 2009
Location: Henderson, NV USA
Posts: 1,083
Registry
Sounding more and more like a bad wire/connector somewhere between the inertia switch and the pump then if you can measure power downstream of the inertia switch but not at the pump. Good luck with the hunt.

There is a copy of the starting and charging wiring diagram in one of the threads recently. I am not at the computer I have it on or I would post it again for you. May get you going until you can get the rest maybe? You can follow the wiring then and check it in sections.

Edit - Silly thought but I have been caught out by it myself. Remember the fuel pump is only on for a few seconds after you 1st turn the key or are cranking (if it’s working right). If you are checking for power after that you won't see it as the relay is out. You will have to have somebody run your ignition switch and keep turning it on and off every few seconds while you trace or you won't see anything. Better to check for continuity of cables and cross check for continuity to ground where it shouldn't be. That way you can confirm the wires without needing power on them.
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
90, 97, 97 d90, d90, fuel

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
FS D90 EFI fuel pump ECR For Sale - Parts 0 June 27th, 2008 02:46 PM
Rats! Now my D90 won't start. No power to fuel pump jcasteel Defender Technical Discussions 8 March 15th, 2005 09:42 AM
Fuel Pump noise Campbell Defender Technical Discussions 3 December 9th, 2004 10:08 AM
Fuel lines for NAS D90 with 300tdi? Chris Cox Defender Technical Discussions 3 December 5th, 2003 04:20 PM
Fuel Pump / Sender 95 D-90 Nigel Buchan For Sale - Parts 1 November 20th, 2003 11:03 PM


All times are GMT -5. The time now is 02:32 AM.


Copyright