No Start! Fuel Pump? Immobilizer?

[dr335i]

So tonight I got a hell of a surprise, the LX470 let me down! I drove it to the gas station and when I hopped back in it just wouldn't start. Just sits there spinning and spinning but doesn't catch. As it was 11 at night I was somewhat limited in what I could do but heres what all I checked:

Disconnected the battery to reset the computers... no dice

Then, I checked the EFI Fuse. It did look a little burnt on the left side, and I've read on a few threads here that there is a flaw in the fusebox on that specific pin. The fuse was not blown though, and I put a 30 AMP in there at the advice of one thread here, still no start.

I pulled the EFI relay which looks good, I didn't see any signs of it not working. Then I tried to jump the bottom right terminal with the positive lead on the battery (Coming from this thread: My immobilizer fix - Terminal D in the picture). This is what suprised me because many people in that thread did the same thing with positive results. It sparked instantly. Couldn't even attempt to do that test. I did have the fuse in place when I tried it and the fuse didn't blow.

Next I pulled off the intake hose to the engine and sprayed a little starter fluid in there. It did seem like it wanted to crank but wouldn't run.

It's definitely some kind of fuel issue. The signs are pointing to a fuel pump but it's just hard for me to believe that because the truck has been running flawlessly. Not once was there any indication of a fuel pump going out. Plenty of power, no misfires, no whining. Truck ran perfect and then five minutes later wouldn't crank. I'm not ruling out an immobilizer issue. I'll have it towed to a shop Monday if I can't make it run tomorrow but I'd really appreciate anyones suggestions. Thanks!

 

[medtro]

I pulled the EFI relay which looks good, I didn't see any signs of it not working. Then I tried to jump the bottom right terminal with the positive lead on the battery (Coming from this thread: My immobilizer fix - Terminal D in the picture). This is what suprised me because many people in that thread did the same thing with positive results. It sparked instantly. Couldn't even attempt to do that test. I did have the fuse in place when I tried it and the fuse didn't blow.

Try connecting the positive lead to terminal F, not D.

 

[2001LC]

You could also see if you've fuel pressure by disconnecting fuel line coming out fuel filter. Typically the way to do this is by cutting power to the pump and then cranking engine to relieve pressure in fuel line. Then remove line from fuel filter. Connect a hose from filter to a catch can and crank engine.

This won't tell you why no fuel, just confirms no fuel is issue.

 

[Greenbean]

@dr335i You figure this out?

 

[FJ60newb]

Was this ever figured out? My wife’s is doing the same thing...

 

[dr335i]

Was this ever figured out? My wife’s is doing the same thing...

Yes it was actually. It was the immobilizer issue. I’m on my phone now so I don’t have the posts to link but essentially it would just crank forever, the check engine light was not coming on when you turned the ignition on. This is apparently a thing, if the CEL isn’t coming on don’t even bother turning the key.

There’s a solution here in a thread somewhere. More or less you need to bypass the EFI relay. Since my car was in a gas station parking lot I did this by pulling the relay out and jamming a piece of wire between two of the contacts the relay plugs into (if you search you’ll probably find the thread where he says which two)

The only real fix is to replace the fuse block. Like $450. I declined. In the same thread that details this problem, he offers to sell a little kit that relocates the relay. I ended up just going to Home Depot, buying the wire and contacts, and making one because I needed the truck the next day, but if I had a day or two to wait I would of much rather bought his because it was much cleaner! Hope this helps, if you haven’t found that thread by the time I’m home I’ll dig around for it and send it to you

 

[Greenbean]

I never really figured mine out, it was SO sporadic when it did it and would restart if you waited about 30-45 seconds. I ended up just replacing the fuel filter, fuel pump w/pre-strainer, plugs and Denso (new) coil packs. Mostly for PM thoughts, I just turned over 450K and she runs so strong and doesn’t burn any oil. Got an excellent report card from BlackStone Labs to boot!

I also have a Crank Position Sensor (Denso) and Cam Position Sensor (OEM) I’m going to replace when I return home from vacation.

I intend to purchase the EFI “kit” and keep it in my glove box for future use if needed but the second time the rig stalled I was driving it and I confirmed 100% then, NO CEL and NO Immobilizer light flashing, so “Technically” it’s not that.


We are driving this 100 into the ground! Lol... Lord willing.

 

[FJ60newb]

@dr335i thank you for getting back to me, I have figured mine out. It wasn’t an immobilizer issue. Mine happened to be a fuel pump and strainer issue.

@Greenbean thats awesome to hear! Mine currently has 332,436 and still rolling I also intend on keeping ours forever.

 

[blatant]

Link to lots of related theads. Including @medtro fix.

100 series cranks but won't turn over / start

I just had this problem tonight, 1st time, ever. 2001 lc. 205k. Wouldn't start but cranked strong as could be. Tried it a couple time and it started fine and good to go. Really stunk though. Meant awful situation being stuck! So I've searched and read all the threads I could find. In...

forum.ih8mud.com

 

[Greenbean]

@dr335i thank you for getting back to me, I have figured mine out. It wasn’t an immobilizer issue. Mine happened to be a fuel pump and strainer issue.

Can you tell me how you diagnosed it or found out that was the issue?

Thanks,
GB

 

[900exdriver]

I’m stuggling to find a solution to my hard to no-start issue. New battery, fuel pump, fuel filter, fuel pressure regulator, fuel damper, injectors, EFI Relay and fuse, spark plugs, MAF, Crankshaft position sensor, and some new rubber hoses.

I replaced a few coils thinking the discolored ones weren’t running properly and for whatever reason weren’t throwing codes. I’ll be replacing the last four when they become back in stock.

Prior to getting my trans rebuilt the truck showed no signs of no-start issues. I’m starting to think maybe they bumped something. I have zero codes. Once it starts it runs great. Drive it around, park it, come back and starts right up. Sit over night and it’s tough to start it. Once it gets going it runs rough for 10-15 seconds. Immobilizer light goes out when key is inserted.

The other day I found the positive terminal connector was split. Thought it was the issue and replaced it. No luck.

Ran techstream this am. When it does run rough for that first 10-15 seconds I was thinking it was the MAF. But it’s brand new. Looking at the O2FT B1 S1 it’s at 99.15%. Is that number too high for idle? 02 sensor?

 

[Greenbean]

Brother I commend you for diving in like a pro!

I hate issues like this! Just takes some of your confidence away in a vehicle.

I hope you get it sorted out soon man.


Does it just turn over and not want to fire? Then fires up and runs rough for a bit?

Did anything get better along the way with the components and parts you replaced?

 

[gatormark91]

When you get the no start issue, and you've cranked it for a bit, pull one of the plugs and see if it's wet with fuel. If it is wet, you don't have a fuel issue. If that's the case, check all the grounds, I'd bet you have a bad ground wire somewhere.

 

[Greenbean]

Good call on a possible ground issue,

Pay special attention to ground locations around or on the transmission and such. You said it was work3d on recently right?

My money is on a ground not secured tightly.

 

[900exdriver]

Thanks guys. I’m certainly getting close to my wit’s end. Especially, since I’ve thrown almost everything but the kitchen sink at it. Or a big f’in hammer

Definitely a good call on a ground. I’ll check the FSM to find the vehicle grounds locations. The shop that did the tranny rebuild may bumped something.

When I replaced the CPS it seemed to start up fairly quick but hasn’t cured it. I see the camshaft position sensor is under the SFI system. I may as well give that a shot after looking at the grounds.

When it does start (usually 2-3 attempts) it runs rough for 10 seconds or so then it’s purrs beautifully.

 

[2001LC]

Have you inspected the O2 sensors to make sure all sensors and wires housing blocks sung.

 

[900exdriver]

Have you inspected the O2 sensors to make sure all sensors and wires housing blocks sung.

Definitely something I’ll put on the list to check. When it starts it smells rich. Making me think it could be the O2. But thank you. I’ll be taking a look

 

[sacman]

Did the OP ever figure out what the problem was?