By ZPukajlo on Wednesday, June 20, 2001 - 09:55 am: Edit

Just the other day I made a short trip with my D1. About one mile. Anyway, when I came back to start it nothing happened. All you heard was the starter trying to crank over.
I didn't smell any gas nor did I hear any other sounds. The electronics all seemed fine. Also, there wasn't any extra lights lit up on the dash. I didn't have time to mess with it and left it overnight.
13 hours later I was ready to fiddle around with this problem. I was going to push the inertia switch, but decided against it. Good thing because the sucker kicked over. At this point I could smell gas for a little bit. The idle held at 750, but you could tell it was a bit on the rough side.
Any idea's as to what the problem may or may not be? I do some remote, high elevation 4wheeling and don't want this problem recurring or in the back of my head. Thanks for any advice!

Zane

By dave on Wednesday, June 20, 2001 - 11:01 am: Edit

How many miles on the Disco? I had a fuel pump that was going bad that gave me similar problems. It was a bitch to diagnose. The pump would run and test OK but it would just crap out sometimes. Would not start....then it would.

There is a thread here somewhere about the lifespan of disco fuel pumps. If I remember right they tend to start going south after 100K. My Disco has 130K on it but the pump that I pulled out had a manufacture date of '96 (94 Disco) so it had been replaced before.

FYI: A new pump was $219 from British Pacific.

By ZPukajlo on Wednesday, June 20, 2001 - 12:43 pm: Edit

The Disco has almost 40K on it. It had been a leased vehicle until I bought it. Let me add one more thing to this message. I ran it for a mile this afternoon. The idle smoothed out as the engine warmed up, but it was hanging around 550 - 600 Rpm's. When I turn the AC on the Rpm's jump up to 650 - 700. I'm sure that this is a seperate problem, but it can't be normal can it? Anyway, I appreciate any and all advice!

Ps This was the first time that the Disco didn't start up.

By Jarrod on Wednesday, June 20, 2001 - 01:03 pm: Edit

I've had that same problem every once in a while. When I lock and unlock the truck again using the keyless remote, it starts right up. I'm not sure what's the problem or how to fix it, but it works for me. Has anyone else ever noticed this, and does anyone know how to fix it. Its annoying, and it seems to be occuring more and more now.

By dave on Wednesday, June 20, 2001 - 04:27 pm: Edit

40K is too soon for a pump. Well, should be at least.

What year is it?

If it fails to start again, see if you are getting spark when you try to start it.

By ZPukajlo on Thursday, June 21, 2001 - 03:37 am: Edit

It's a '97.

By John on Thursday, June 21, 2001 - 04:17 am: Edit

I had to replace my fuel pump at 35K...it was getting hard to fire up...new fuel pump fixed the problem. You can check your fuel line pressure at the injector manifold to do a quick check.

By ZPukajlo on Thursday, June 21, 2001 - 06:21 pm: Edit

Thanks for the info!

By jcw on Friday, June 22, 2001 - 02:47 am: Edit

This probably isn't your problem, but thought I'd add it to this thread, since has to do with hard-starting. '95 Disco 3.9, runs and starts great...except when turned off hot, then let sit for 30min to 2 hours or so, then it's hard to start. Will crank maybe 6 or 7 sec before starting...but, if pedal is depressed 2/3, then starts pretty quick. Very repeatable.

Have done some trouble-shooting. Fuel pressure builds fine, even when cranking difficulty. Makes no difference to hold the key on, let FP build pressure, then crank. I changed the plugs, and found all looked good except #5...wet. So, I figure that injector is leaking. The fuel pressure holds for awhile when turned off, but finally drops to a low value after about a half hour..about the time when the problem develops.

Next test: After stopping when hot, I use a tire valve wrench to loosen the core of the Schrader valve on the fuel rail, to release the pressure. I leave it loose for, say, an hour. (Leave a note on my seat so I don't forget to close it back up before starting!!) Tighten the valve, and the Disco starts normally, with perhaps just an extra revolution or two of crank.

My theory: the drop in fuel pressure caused by the leaky injector allows the gas in the fuel rail to vaporize in the hot engine compartment...filling the rail with plain vapor under slight pressure. This continued pressure keeps the injector leaking, losing all the gas in the rail. When starting hot, the computer isn't going to open the injectors much, so it takes a lot of cranking to clear the vapor...but pressing the pedal makes the computer open the injectors more, clearing the vapor quickly. Leaving the Schrader valve open bleeds off any vapor as it forms. Since there's no vapor pressure buildup, and no fuel pressure to begin with, very little fuel leaks from the injector, leaving the rail with mostly fuel instead of vapor...and thus an easy start.

As posted in another thread here, I'm getting ready to change the suspect injector. Haven't done those before.

John

By ZPukajlo on Friday, June 22, 2001 - 05:13 am: Edit

Well, it happened again today! The engine was cold this time. Just cranked. Tried jcw's method of depressing the pedal, but it didn't work. For giggles I then locked and unlocked the truck like jarrod does. It turned right over. Am I missing something here! Everything else was the same that I posted in the first message. Two no starts in three days isn't a very good track record! As always any and all info is much appreciated.

Zane

By ZPukajlo on Friday, June 22, 2001 - 07:47 am: Edit

Got to thinking. Do you all think that somehow the security system is causing this? The Landy did turn over after it was locked and unlocked. What do you all think?

By Jarrod on Friday, June 22, 2001 - 10:59 am: Edit

I though so. I've been thinking its caused by the security system as well, but I can't figure out what causes it. The only thing that I can come up with is the fact that the security system turns off the fuel pump when the alarm is activate, and somehow, somewhere along that line a switch or something doesn't operate correctly and sometimes shuts off when its not supposed to. Locking and unlocking the alarm resets it - its got to be some relay or something that also associated with the alarm system.

By Zpukajlo on Friday, June 22, 2001 - 02:54 pm: Edit

My guess is that it is the security system itself. I lock my truck 95% of the time. It maybe assuming that the vehicle is locked and then shut off the pump. Only arming and then disarming will everything be reset to normal. Of course, this is a guess and it could be a switch or relay.

By Jarrod on Sunday, June 24, 2001 - 05:57 am: Edit

Well, I've left my truck unlocked before - I have a garage. And even though it was simply shut off and unlocked, there have been times where it hasn't started up - only turned over. I think somehow - a switch or relay is inadvertently turned off when the truck is turned off - something its not suppose to do, and sometimes when you lock the truck it masks the problem because when you unlock it - everything is reset. I saw somewhere about an ECM (?) that controls the fuel pump by the security system. I wonder if that has anything to do with it.

By ZPukajlo on Sunday, June 24, 2001 - 03:23 pm: Edit

Anything is possible! At least we managed to narrow down as to what the problem may be. Looking over an electrical scheme may help in determining if there is a seperate relay or switch. If not, then it may be the ECM or the security system itself. Time to do some research.

By jman on Monday, June 25, 2001 - 05:16 am: Edit

FWIW..I have gotten in my truck, using the keyless, tried to turn the thing over, and nothing. I lock the doors with teh remote (sitting in drivers seat) and unlock them, and it always turns over. happens liek once every 4 months or so...I just deal with it