2000 LX 470 cranks but will NOT fire (3 Viewers)

[arbetrader]

Ok Boys & Girls, brief history........

I've been working on all sorts of cars & trucks for 40 years. Learned THREE things,

1) Look at the basics first

2) Look at the basics AGAIN

3) You will keep learning

POP QUIZ TIME.......

Look carefully at the fuse shown in the attached two pictures

Q. Is the fuse shown in the picture GOOD or BAD?

HINT...It looks GOOD and it checks out for continuity.

Do you have your answer yet?

I have been battling this problem for 5-6 hours and have been told to CHANGE THE FUSE. Did I change the fuse? NO, I eyeballed it twice, cleaned the socket in to which it fits once AND confirmed continuity with my OHM meter.

Have however just CHANGED THE FUSE and, guess what....Problem solved.

Thank you to everyone on this one but SPECIAL kudos to ARBETRADER & TRAVIS 351. 20 cent fix!!!!!!

I'm glad that worked for you. I was also thinking it really sounds quite redundant that something seemingly so ambiguous would make the difference. So chalk it up to 3 rigs (that we know of so far) that this has been the answer to. Happy Wheeling (or mall cruising)

 

[cboyd]

Well thanks for posting. From now on, I'll just remember, change the fuse first! Even if it looks good... Cheap insurance.

 

[barneyhyphen]

absolutely incredible. Not only did it LOOK good, it also carried a current and tested good with the OHM meter???

Still don't really believe it n waiting for the other shoe to drop.

Hasn't happened since the fuse change! Go figure.

BH

 

[paflytyer]

Great stuff. Good to hear it was a nice simple fix. I'm storing this one away for reference

Same! An amazing wealth of knowledge is available from the members of this site.

 

[paflytyer]

absolutely incredible. Not only did it LOOK good, it also carried a current and tested good with the OHM meter???

Still don't really believe it n waiting for the other shoe to drop.

Hasn't happened since the fuse change! Go figure.

BH

It looks good and tests good....
Can anyone tell me why it's no good? For being such a simple fix, It sure has me confused.

 

[APKhaos]

It looks good and tests good....
Can anyone tell me why it's no good? For being such a simple fix, It sure has me confused.

Its possible that the fuse metal stamping is cracked. It tests OK at low voltage but the crack/fault opens when its carrying rated current. Rare, but known failing mode for these stamped fuse links.

 

[pwcummings]

Ok Boys & Girls, brief history........

I've been working on all sorts of cars & trucks for 40 years. Learned THREE things,

1) Look at the basics first

2) Look at the basics AGAIN

3) You will keep learning

POP QUIZ TIME.......

Look carefully at the fuse shown in the attached two pictures

Q. Is the fuse shown in the picture GOOD or BAD?

HINT...It looks GOOD and it checks out for continuity.

Do you have your answer yet?

I have been battling this problem for 5-6 hours and have been told to CHANGE THE FUSE. Did I change the fuse? NO, I eyeballed it twice, cleaned the socket in to which it fits once AND confirmed continuity with my OHM meter.

Have however just CHANGED THE FUSE and, guess what....Problem solved.

Thank you to everyone on this one but SPECIAL kudos to ARBETRADER & TRAVIS 351. 20 cent fix!!!!!!

DUDE YOU GUYS ROCK, exact same problem, swapped out the efi 20a fuse w the stereo fuse (I didn't have a spare) and BAM! Fired right up. Props to everyone!

Sent from my iPhone using IH8MUD

 

[pwcummings]

Alright, so the above fix has worked for me, however, 2 times since then it has done the same thing where she cranks, but won't start. When it's happening the immobilizer light remains flashing throughout the cranking. I swap out the fuse and she disengages the immobilizer and fires right up. I am now back to the original fuse (which I kept). She's running fine now but just waiting for it to happen again... ANY IDEAS? I have an extended warranty but this kind of ghost problem is pretty difficult for them to diagnose I would think.... Could this have anything to do with the starter contacts? She cranks fine... I wouldn't think the starter contacts wouldn't effect the immobilizer right??

I am thinking of tearing into the fuse box and thoroughly cleaning in there, has anybody done that yet? Any input would be greatly appreciated. I consider my hundy very reliable but with all the time I spend up at the mountain, I can't afford to get stranded up there hooks she give up the ghost for good....

Sent from my iPhone using IH8MUD

 

[Bombdefuzer]

I worked part time for a really good Toyota guru and his advice was:

1. It was probably something you did.
2. Start with the cheapest part first.
3. Don't worry the last bolt will snap.
4. Don't drink beer when working on your car.

 

[rhino8005]

cleaning fuse/relay box

I have had this problem a half dozen times over the past year. For me, the problem seems worse when it's warm out. Do you guys remove the relay box to clean it?

From reading on the 80's forum, seems there are a couple items that cause the efi fuse to blow. A short in the O2 sensors or a short in the fuel pump. I realize ours our not blowing, but when it starts happening regularly I feel there must be another issue. Since both of mine are original equipment I wonder if replacing either or both would help? I am going to start with cleaning the fuse/relay box, but i am brainstorming if that does not work. I am at 195k on the clock.

Thanks in advance for any advice,
Ryan

 

[LCtygrys]

Great thread. My '02 died at work and after being towed to the dealer, replacing the battery and that EFI fuse (all $362) it ran fine until two days later (today) when it wouldn't start again. Cranks but not starting. Called the dealer and the tech said put in a 30 amp fuse instead of the 20 amp. It fired right up. The 20 amp fuse tested fine for continuity.
So herein lies the questions...

1) What is physically wrong with these fuses that test fine but stop working?
2) What am I going to fry by using a 30 amp fuse instead?
3} I have been running on very low fuel levels lately. Could my fuel pump be overheating and tripping out? The car only won'y start after sitting for all day though and is cold.

BTW I looked underneath to see if the wire bundle was rubbing on the driveshaft as suggested from another thread but mine isn't built that way.

I should also mention that last week I went through a series of huge puddles ~24" deep (what a blast) in case that has anything to do with it. I drove it 7 hours back from NY without a hiccup though and these problems started several days later.

thank you you wonderful helpful people

 

[BOB F]

Well after searching the site I found this thread ad I will be the third user who swapped out the 20a EFI fuse and it started right up. One of the legs of the fuse was black with something so I will get in there and clean the contacts.

Hopefully this will help others as well.

 

[El Cid]

cleaning fuse/relay box

I have had this problem a half dozen times over the past year. For me, the problem seems worse when it's warm out. Do you guys remove the relay box to clean it?

From reading on the 80's forum, seems there are a couple items that cause the efi fuse to blow. A short in the O2 sensors or a short in the fuel pump. I realize ours our not blowing, but when it starts happening regularly I feel there must be another issue. Since both of mine are original equipment I wonder if replacing either or both would help? I am going to start with cleaning the fuse/relay box, but i am brainstorming if that does not work. I am at 195k on the clock.

Thanks in advance for any advice,
Ryan

I don't know if the fuel pump can short per se, but this EFI fuse continually blowing isn't an isolated issue. Not ironic either that we're both in Texas...I've just replaced an 02 sensor, but I may just punt and do the pump too..

 

[El Cid]

From reading on the 80's forum, seems there are a couple items that cause the efi fuse to blow. A short in the O2 sensors or a short in the fuel pump. I realize ours our not blowing, but when it starts happening regularly I feel there must be another issue.
Ryan

In my case, someone had wired the 02 sensor incorrrectly. This caused a short. It's running well now that it's replaced...but damn, what an unholy beat down.

 

[carsdad]

I am simply blown away by the potential complexity and list of answers to this problem. It happened to my wife while at a Starbucks near Disneyland. We live in Phoenix so needless to say I was very bummed at the prospect of retrieving the car. After about 15 minutes with the key in the ignition it fired up while I was on the phone with her. Elated screaming over she made it home. I found the EFI fuse theory and pulled i. It was chalky but looked ok after cleaning. Did not have a problem for exactly another month (that being today). Reading previous posts in this thread I decided what the heck. I'll go buy a stupid fuse. Replaced 20 amp EFI fuse and immobilizer light shut off with key inserted and car fired right up. Obviously there is some bizarre link between the EFI and immobilizer. I am dumbfounded that this worked even though I cleaned the old fuse and inserted and removed multiple times to insure good contact. Next up, I need another key. We are down to one remote/ master. If that disappears I will be bummed. However Locksmith Charlie is in Phoenix and i have spoken to him twice now about keys. He apparently has the ability to reprogram the ECU if necessary even without a master key present. So there is hope these days. Anyway I just had to post my experience for the future frustrated.

2001 LX470

 

[blatant]

This old jewel. Glad she's home safe and sound.

100 series cranks but won't turn over / start

 

[DubYoda]

I hope someone sees this thread resurrection post. I have a 99 that I swapped out my original engine that had a cylinder failure and a top end rebuild was 3x a junkyard one with less than half the 330,000 miles. After we got it done for 1 week it drove about 10 miles per day to work for me and ran great but started stalling randomly then stopped starting altogether.

I also have a 2001 so I put them side by side and started swapping all the above fuses and relays to see if anything would change. Nothing did . I replaced the timing belt and water pump when I put the new engine in. After this issue I swapped the TBS and CPS for new ones and the non-starting issue persists.

The fuel pump works great and the filter is new I shot about 5 oz. of gas all over before I could get my helper to stop cranking when I had the line unplugged on the post filter to test. I don't know if all of the injectors could be clogged at once but if that's possible I'll reluctantly address that if so.

Is there any chance my immobilizer locked me out? I heard that the valet mode only allows 50 miles before shutting it down. Is there some possibility the new engine needed to be programmed to the ECU? I don't have the ECU from the junkyard LC. My keys shut off the light when cranking and are master keys, they still lock and unlock the doors as well.

Any insight in the immobilizer shut out would be appreciated. If that is it does it require a shop to reset it or is there some procedure I can do in my garage?

TIA

 

[Mauser]

I hope someone sees this thread resurrection post. I have a 99 that I swapped out my original engine that had a cylinder failure and a top end rebuild was 3x a junkyard one with less than half the 330,000 miles. After we got it done for 1 week it drove about 10 miles per day to work for me and ran great but started stalling randomly then stopped starting altogether.

I also have a 2001 so I put them side by side and started swapping all the above fuses and relays to see if anything would change. Nothing did . I replaced the timing belt and water pump when I put the new engine in. After this issue I swapped the TBS and CPS for new ones and the non-starting issue persists.

The fuel pump works great and the filter is new I shot about 5 oz. of gas all over before I could get my helper to stop cranking when I had the line unplugged on the post filter to test. I don't know if all of the injectors could be clogged at once but if that's possible I'll reluctantly address that if so.

Is there any chance my immobilizer locked me out? I heard that the valet mode only allows 50 miles before shutting it down. Is there some possibility the new engine needed to be programmed to the ECU? I don't have the ECU from the junkyard LC. My keys shut off the light when cranking and are master keys, they still lock and unlock the doors as well.

Any insight in the immobilizer shut out would be appreciated. If that is it does it require a shop to reset it or is there some procedure I can do in my garage?

TIA

Since your security light os going out when you put your key in the ignition it is being recognized by the ecu as the proper key. I have never heard of "valet mode"?

 

[DubYoda]

Since your security light os going out when you put your key in the ignition it is being recognized by the ecu as the proper key. I have never heard of "valet mode"?

I once read that a valet key also limited driving to 50 miles then immobilized the car, I obviously can't find that now

Maybe that manual that I keep seeing in my dreams after having all these issues?

 

[NickSonoma]

I had the same issue today, 04/19/2020. After realizing I didn’t hear the fuel pump whirl with key in, I checked the fuse. It looked used but functional. I replaced the 20A with an available 30A and it fired right up immediately.

I can imagine a ton of things that could cause a fuse to blow, but I can’t think of anything that would cause them to fail without blowing. Unless this fuse is attached to the trigger pin on a relay. I could imagine the fuse could eventually not have enough continuity to engage the electric magnet/coil in the relay. If that circuit does feed directly into a relay, it would be interesting to see if replacing the relay and not the fuse would also work. If that’s the case it would answer a lot of questions.