97 Disco Fuel/Other Issue

N

npvos

Member
Apr 6, 2016
16
0
Birmingham, AL
Howdy,

My 97 disco was giving me issues around this time last year. Replaced the fuel filter...no issue for the entire year. Around May it started struggling (misfires, hard to start, loss of power) and then a few weeks later I was driving and it just died. Got it started. Drove it to the grocery store...dead. Would crank, but not start. Usually, if I let it sit for 30ish minutes it would start right back up and drive fine. No dice. Got it towed. Let it sit overnight. Got in the next morning. Boom. Started. Drove to work (less than 10 minutes) and it died before getting there. Crank, crank, crank, start...about 5 minutes after dying. Same story on the way home. Now I have it in the driveway. I can start it. Move it around. Park it. Shut it off. And then I will try and start it after...no start. Cranks but no start.

I'm not getting any error codes, so I don't have anything to go off of. My suspicion is a fuel pump...but I have not put a gauge on the rail to check PSI. Not sure what might be happening. Any suggestions?

Cheers,

Nate
 
E

ezzzzzzz

Well-known member
Apr 22, 2010
604
7
SE Va
The first thing to check is the fuel pressure before going any further. You can make a quick check though. Let it sit until it starts and drive until it quits on you. Don't try to restart! Just turn the key off and pop the hood. Using a catch rag and not facing it directly, push in the schrader valve on the fuel rail. It should momentarily 'spray' fuel under pressure and immediately stop because the pump is off. If it just dribbles or nothing comes out you probably have a failed pump or..... the wiring harness at the fuel pump is failing (a known problem with some D1's).
 
N

npvos

Member
Apr 6, 2016
16
0
Birmingham, AL
Good to know! Is there a way to check the wiring harness? This is probably an important factoid...my fuel gauge works...occasionally. Had an alternator go out about 2 years ago and it started giving me grief then. Just says I'm empty until a little less than 1/4 of a tank. No idea if these are related. My assumption...yes. But you know what they say about assuming....
 
p m

p m

Administrator
Staff member
Apr 19, 2004
15,630
863
58
La Jolla, CA
www.3rj.org
There's Schrader valve on the passenger side of the fuel rail. Buy or borrow or rent a fuel pressure tester, and measure what the pump cranks out.
I don't remember the exact numbers, but if it shows less than 30 psi when the engine is running, less than 35 psi a couple of seconds after ignition being turned on (remember that you need someone else to turn the ignition on - the pump will only stay on for a few seconds if the engine is not started), and drops rapidly when the ignition is off, you need to look at either the pump or leaky injectors.

Next step in checking the pump is presence of 12V across the pump terminals.
There's a round cover in the cargo area, under carpet and under-padding. Take it off and you'll have access to the pump.
The area where the connectors live (your truck is likely Advanced Evap, so you also have a connector for tank pressure sensor) is prone to accumulate wet dirt, so connectors may corrode. I don't remember if a 97's pump would have an additional connector somewhere near the fuel filter area (should be visible from rear passenger wheelwell) - if yes, it is also prone to corrosion.
 
X

XCELLER8

Well-known member
Sep 21, 2009
249
12
also, the fuel pump and fuel gauge are fed by a short ( why did they do THIS) harness that is accessible from over the rear driver's side wheel well..its laying on top of the frame and tank, if that's corroded or otherwise afu...the gauge can read or not, and the power to the pump can be interupted.....personal experience..
 
N

npvos

Member
Apr 6, 2016
16
0
Birmingham, AL
Thanks for the info every one! I haven't had any time to work on my truck recently...working on updating a kitchen. I will let you know as soon as I get to the bottom of it/come up with more questions!
 
N

npvos

Member
Apr 6, 2016
16
0
Birmingham, AL
Howdy every one! Replaced just the fuel pump and all is right in the world...for now! I just used an ACDelco EP241 pump for the rebuild (plus strainer and fuel line). I've been driving on this for about a week now and all seems good. Trying to put it under as much stress as possible too. Steep hills, hot temps, high RPMs, etc. So...for the time being...Nigel isn't being a punk. Fuel filter was replaced recently, FYI (those original metal weather caps are butt to get off though...the clamps are the way to go!).
:bigok:
 
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