'95 D1 3.9L. Engine dies, cools down, runs, dies....

skrufy

Well-known member
Nov 26, 2004
53
0
Hi Gearheads-

Haven't posted for a long time as my '95 D1 runs like a top. Owned since new, have had my fair share is issues familiar to many here. 165k miles. Amsoil everywhere. Have over the years replaced battery, fuel pump, temp sensors, MAF sensor, plug wires, et al, as well as the usual tune up stuff.... have the factory shop/electrics manuals, parts manuals on microfische ( you youngsters google it - that's the way it was done in ancient times, before the iPad...) have always worked on my own vehicles, am pretty confidant with a wrench, but not a professional- could be though.....

So- no codes, no lights- Check engine. etc, battery fairly new, good connections, good spark, good fuel pressure at the rail, good residual fuel pressure per manual, recent plug wires/plugs- all fuses good- interior/engine bay. Live in the mountains of Arizona, so no real rust/corrosion problems anywhere....

Ran thru 9 pages/425 postings in this forum under the search 'engine quits' - so if I missed the obvious solution in someones post, sorry I missed it. hate wasting everyones time, but am a little stumped and seek the wisdom of the Forum and those a lot smarter than me.

Over the last few days, the D1 started to stumble- intermittant surging if you will on the engine- then dies. You let it cool for sometimes as little as 5 minutes, then it cranks/runs per normal- then may run for an hour- then dies again. Have done static runs in the driveway in the morning- cranks/ runs, then dies after 4-5 minutes.

I initially though it was fuel pressure- then got out my fuel injection tester- don't believe fuel is an issue here. i do have a new fuel filter i have not installed yet. Runs at 35-40psi, 30 psi residual after shutdown/quits. I don't have my best pressure gage on the rail- so the actual numbers may be a bit better- or worse.... On start w/o ignition, the fuel pump kicks right to 30 psi.....

I do have a Mallory distributor on the D1- immediately suspected the optical pickup module (Mallory 6100M or Accel 2005)- tested the coil voltages and module- all appears to be ok w/in Mallory specs. Have a Mallory surge filter in line to protect the module- by passed that, problems still exist, so the filter appears to be a-ok. Have a new pick-up module on order- maybe get it tomorrow....

So, ideas on what is telling the ignition to quit or other ideas here I am missing. Any inputs will be greatly appreciated. Hopefully something simple, and obvious.... Otherwise the D1 has been great- and nothing out there rides better in the forest.

Thank you-

Tim
Alpine, Az.
 

robertf

Well-known member
Jan 22, 2006
4,781
356
-
I saw this on another 95 Disco, its been a few years so I don't remember all the details but I remember all the basic checks passed, fuel spark compression, blinking injector noid light. Taking the underhood fuse box completely apart and cleaning it, putting it back together seemed to have fixed it after many hours of rechecking the components and even throwing a few parts at it. I'm still not sure what was going on there, but it can't hurt to unplug the connectors under the box and clean them up then reinstall.

your fuel pressure should be around 37 psi minus engine vacuum, so either 0 rpm or wide open throttle that should be the reading, and it'll dip down to around 27-30 when idling when the manifold vacuum lowers the pressure through the regulator.

get a rovergauge cable and check it on a laptop to see if you are maintaining communication with the ecm. you can also trigger the fuel pump on while the engine is off to check steady state fuel pressure.
 

jims95

Well-known member
Apr 20, 2004
203
1
Upland, California
Have you ever changed the fuel injection relays, in the right front kick panel? Your truck is 22 years old. My 1995 RRC had these symptoms and a Land Rover mechanic I know, told me to replace them. Afterwards there was no more stumble-intermittent surging.
 

skrufy

Well-known member
Nov 26, 2004
53
0
Thanks Robert and Jim-

Where to get the Rovergauge cable? haven't heard of it before, and do I need software- like Textbook- for my Mac laptop?

-Will put the new fuel filter in in the morning to see if the pressure goes up- I suppose there could be a momentary glitch that shuts the injectors down, but doesn't show on the gage. Will break out the adapters and try and connect my bigger, better Bosch fuel pressure gauge to the fuel rail...

Will attack all all the electrical connectors you have mentioned with Elec. contact cleaner, and I usually put dielectric grease on everything as well, freshen up contacts with a wire brush on my Dremel....

Jim- will pull out those relays- freshen the contacts, and I think I have a new spare relay anyway...

Will keep you/Forum informed.

Many thanks-

tim
 

robertf

Well-known member
Jan 22, 2006
4,781
356
-
rovergauge cable is kind of homebrew. theres been some people selling them, maybe you can find one on google

its a ftdi usb serial ttl cable with a resistor soldered in place to drop the 12v to 5, and the lucas TTS female plugs in a 5 way connector

the pins are availabe here: http://3waycomponents.co.uk/Lucas-R...le-Receptacle-Terminal-0.65mm-1.00mm-51102699

you need 3, buy extra since they take a few days to get here.

the connector shells are NLA, you have to find one from a part out rover or 3d print one. I think theres a model on thingiverse.com Ive got one I designed that works great but haven't uploaded it anywhere. If you get in a pinch and that thingiverse one is a bust I can probably put a working one out there.
https://www.thingiverse.com/thing:139136

info on rovergauge. I hear it works on mac os, never tried it. Work fine for me on windows 7 through 10. You do have to configure the cable with FTDI software that is only available for linux or windows. Its a one time setup.
http://alum.wpi.edu/~colinb/14cux-serial-interface.html
http://alum.wpi.edu/~colinb/14cux-software.html
http://www.ftdichip.com/Support/Utilities.htm#FT_PROG

and that relay is special to the fuel pump and I think ECU. It has 2 87 NO terminals, unlike a standard relay that has a NO 87 and NC 87a

https://www.delcity.net/store/Norma...MI9a-r2bmh1gIVFAeGCh04fAwbEAQYAyABEgJ3N_D_BwE
 
  • Like
Reactions: DiscoClay

Grenade

Well-known member
Oct 8, 2015
111
6
Vegas
I have a 95 as well, and have TS quite a few issues.

I would check double check, and triple check the fuel pump, connections and wires.

Then I would check your fuel pump relay. (Located on passenger side kick panel) Your's should have the metal bodied relay. If so make sure your replacement is metal, they're online mostly, but if you go somewhere online they will supersed to another part number that may work.

Do you have any fault codes?

If you look at my post history you'll see an issue I had where I was dealing with a weird relay click that would cause my 95 to shut off. I trouble shot the problem to the ECU loosing its ability to hold a ground signal on the Fuel Relay. I found this by attaching an LED to the ground side of the coil so that when it would loose the signal, the led would light up.

You do have this schematic / electrical troubleshooting pdf correct?
 

skrufy

Well-known member
Nov 26, 2004
53
0
Hi guys-

Have been away a bit and not much time to fool with the Disco.... what I have done:

-Replaced fuel pump- old one as the bottom of the in spec operating range, but replaced it anyway.
new pump operates at 33-35 psi, holds pressure at 35+ psi after shut off, and gradually bleeds off....

-new fuel filter

-new optical pick up module in the Mallory distributor

-cleaned/wire brushed, then dielectric greased all fuses in the engine bay. this is an Arizona disco- not much corrosion or
moisture. Haven't done the connects to the fuse box- don't expect much dirt corrosion.

Have a spark indicator bulb on #1 plug. The engine runs anywhere from 1-5 minutes, then quits. Fuel pressure gage off the injection rail indicates normal expected fuel pressure. Once the engine quits, it shows no spark while attempted re-starts. Am going to test the coil, which is a matching Mallory for the distributor so a resistance wire is not necessary. Good voltage to the + of the coil when the ignition is turned on and after the engine dies. What I don't know yet is if than white/green hot wire to the coil + is directly from the ignition switch, or comes from the ECM. I smell the fuel while attempting re-starts.

Am stumped at the moment. What other input is telling the engine to run/not run? Don't think this is a fuel issue at all.

Grenade- I do have the above diagram in my "Electrics Manual' . don't have any OBD codes or any other idiot lights on.

Robertf- haven't had time to fool with a rovergage cable yet.

Need to get the Disco rolling!

thanks to all-

Tim
 

aliastel

Well-known member
Sep 27, 2009
942
0
Champaign, IL
When replacing the fuel pump, you should replace the fuel pump lead and plug as well. These burn out eventually. I had a 1996 that would intermittently cut out due to this. Replaced the lead and no more problems.
 

AbnMike

Well-known member
Apr 6, 2016
1,218
117
Western Slope, CO
Does that distributor have a condenser?

If so it's going bad. When going bad they get hot and stop. Cool down and they work again.

If it doesn't have a condenser on it (I'm unfamiliar with that set up) then I got nothing.
 

skrufy

Well-known member
Nov 26, 2004
53
0
Hi All...

In from another frustrating afternoon.... Aliastel- I will check the electrical connector - don't think I have an issue there- but will check it anyway...

AbnMike- the Mallory does not have a condenser, and to the best of my limited knowledge, does not need the ignition amplifier bolted behind the shield near the coil and power steering reservoir.....

Got it to run intermittently for a minute or so- by am not sure why... I cleaned up all the connections to the coil + and - with a dremel, made sure no loose connections. Mallory recommends their coil with their distributor, negating the need for a resistance wire. The primary and secondary circuits of the Mallory test ok resistance wise. When the engine quits- and no spark in my spark indicator on #1- the hot 12v lead from the ignition/key lock switch stays hot at batt. voltage. Turn it over, and no spark from the coil to the block in a test.... was beginning to suspect the key/ignition switch not keeping the wire to the coil hot at 12v- not sure though... It took me a long time to even find the key/ignition switch in the LR factory "Electrics Manual"- and in the depiction I found, it doesn't show all the wires. Will fool with that tomorrow....

I did hook up my old LR issued Bosch coil- got it to run for 5 minutes or so. it was not bolted it- is a coil supposed to get hot while it's working? one might not notice as the metal mounting strap to the forward frame is a big heat sink. Free standing, that coil got pretty warm, and if it continued to run, I suspect it might have gotten too hot to handle...

Since I don't know if the bosch coil provides the same resistance needed by the distributor, I wonder if I smoked my new pickup module? will find out tomorrow when I do that test again....

Have decided to drink some rum and contemplate the best place to tie the boat anchor rope....

thanks to all-

Tim
 

waymore

New member
Jun 24, 2012
1
0
Bham
Sounds like a issue I had when I bought mine...

My issue was the distributor plastic was cracked, and as the truck generates heat it's enough to cause the crack to separate and the rotor to ground out and kill the truck. When you pull the cap off look for any cracks in the plastic that sits below the rotor. If it's cracked it's your culprit. I think I bought a 50 kit from Rovers North to rebuild it but only changed the plastic and it has run fine ever since. Good luck.
 

edthediscoman

Well-known member
Nov 4, 2005
1,377
0
53
Rivertucky, Ca
Perhaps due to heat the inertia switch is triggering for some reason?

I have been fighting a similar problem (replaced wires, plugs, cap, rotor, coil, checked grounds, battery, alternator connections etc etc), turned out to be fuel pump!

I have no idea if its supposed to be on or off during normal operation, but try pressing it again when its hot and see if it helps, or replace with used one.