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- #21
When it comes on, it comes on straight away, it doesn't keep flashing and it doesn't throw any codes.
80 series gear heads plz help! 93 LC80 engine cranks but doesn't fire up, when it firs its shuts off
- Thread starter Jibreezy82
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Thinking it might be intermitent or causing the truck to crank but not stay running thats all.
I thought they were like every other mass air flow sensor and that you could just pull it out and clean it. Sorry, I don't remember what the CEL was doing unfortunately.
Does the engine fire up after a day of sitting? Double check your fuel system.
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- #25
Yes it does, and it remains working. I just drive it this morning, fired from the first click and drove perfect. It's just suddenly and most inconveniently I had my kids with me in the car, the engine dies, CEL stops illuminating when key on "on position" therefore engine cranks but doesn't fire up. Every time that happens I let it set and go through everything I mentioned above then it works again. But that didn't solve the core problem. Something is cutting the current from my EFI fuse between the fusible link and my EFI fuse and I don't know what it is, because every time is lose my CEL, my V- meter reads no current at the EFI fuse, when the CEL comes back on, it ready +12. So frustrating
alia176
SILVER Star
Yes it does, and it remains working. I just drive it this morning, fired from the first click and drove perfect. It's just suddenly and most inconveniently I had my kids with me in the car, the engine dies, CEL stops illuminating when key on "on position" therefore engine cranks but doesn't fire up. Every time that happens I let it set and go through everything I mentioned above then it works again. But that didn't solve the core problem. Something is cutting the current from my EFI fuse between the fusible link and my EFI fuse and I don't know what it is, because every time is lose my CEL, my V- meter reads no current at the EFI fuse, when the CEL comes back on, it ready +12. So frustrating
Don't worry, we'll figure this out. There is a lot of wisdom on this board. We need the FSM pages for the EFI area. Does anyone have a color copy to upload into this thread?
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- #27
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When the CEL isn't lit with the key to run, engine off, the ECU isn't getting power, no ECU power no run.
Connection problem between those two points? Your harness configuration likely differs from ours, but, there looks to be a factory splice in the white wire feeding the EFI fuse? Is the connection good where the white wire connects to the fuse box?
- Thread starter
- #29
Hi. Yes, I unbolted the black fuse box and looked underneath it, really tight space so had to remove the canister first, there is a factory splice, and the connection where the white wire connects to the EFI fuse is good , while the CEL is on I tested with the v-meter while wiggling it.
2 things I've noticed:
1-I turned the AC for 1/2 hour, then engine shut off and the CEL went off, seconds later CEL came back on, started the engine and again, then AC on caused it to shut off immediately.
2- There is a wire I traced, its in the same splice as the harness feeding the black fuse box towards the fire wall pass the igniter, this wire felt really hot, its clipped to an unlabeled square part( tired fining it on the FSM), and whenever I disconnect it's clip, the engine stays running for couple of seconds then it shuts off and wont start unless i connect it again. I've attached pics.
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- #30
I think this is the EFI diagram.
Thats the fuel pump resistor.
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- #32
Thanks, madisonr34. for some reason I couldn't find it on the fsm diagram and i assumes the fuel pump resistor is the black cylinder shape next to the fuel pump relay. Ill have it tested and will check where its connected to on the wiring diagram. But any reason why or is it normal for the wire connected to it to be hot?
This is the wiring for the fuel pump resistor on 1997 lx450.
I know the resistor controls and regulates the electrical current to the fuel pump. The FSM says it should test aprox 0.73 ohms.
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- #35
Thanks!. This is definitely worth checking. Makes scene if its a reason to shut the fuel pump. I need to check if it would cause the CEL to stop illuminating. Another thing I've noticed which my eye completely didn't catch, the Head light R/L fuse connecting wires has been pulled from the black box (where a trace of burned HL 15A fuses), and directly connected to two 20A fuses. now the HL wires share the same loom as the MAIN fusible link>black box> igniter> fuel pump rely and resistor, also the HL loom connects back to the ECU if I understood the diagram correctly. So im guessing what caused the HL fuses to burn could have caused weirs to burn in the loom?
semlin
curmudgeon
just a comment on this. i had very similar symptoms to you in my 94. if it is the same issue you have badly corroded or damaged wire somewhere in the fuel pump system.
it turned out i had a damaged fuel pump wiring harness under the driver's side rear door of my 94. eventually the + wire to the pump totally parted. until that happened it would randomly stall the car out while driving. there was no rhyme nor reason to it. i was able to do a couple of 100 mile+ trips after the problem first showed up, yet sometimes i couldn't make it 5 minutes home. sometimes the car would restart right away, and/or might stall repeatedly, and sometimes it needed a couple of hours and then it started.
i never had (or noticed) the cel light behave weirdly, but i did get a cel 26 and i did have the entire dash blank out on me when trying to start it. i still don't know why that last symptom happened. i suspect you are throwing a cel code like i did, but then you are losing power to the ecu which is erasing the code.
here's the thread.
code 26 and stalls
it turned out i had a damaged fuel pump wiring harness under the driver's side rear door of my 94. eventually the + wire to the pump totally parted. until that happened it would randomly stall the car out while driving. there was no rhyme nor reason to it. i was able to do a couple of 100 mile+ trips after the problem first showed up, yet sometimes i couldn't make it 5 minutes home. sometimes the car would restart right away, and/or might stall repeatedly, and sometimes it needed a couple of hours and then it started.
i never had (or noticed) the cel light behave weirdly, but i did get a cel 26 and i did have the entire dash blank out on me when trying to start it. i still don't know why that last symptom happened. i suspect you are throwing a cel code like i did, but then you are losing power to the ecu which is erasing the code.
here's the thread.
code 26 and stalls
semlin
curmudgeon
- Thread starter
- #38
Hi semlin. Thanks for the tip. I did in fact had my car stall(prior to crank no start issue) reason why I changed the fuel pump, I left the garage for an hour came back and saw the intelligent mechanics had lowered my tank instead of lefting the mid seat and do it from top. That didn't solve the problem
Hi semlin. Thanks for the tip. I did in fact had my car stall(prior to crank no start issue) reason why I changed the fuel pump, I left the garage for an hour came back and saw the intelligent mechanics had lowered my tank instead of lefting the mid seat. Replacing pump didn't solve the stall problem. Anyways, few months later (crank no start) issue. So maybe they yanked something while doing the fuel pump job. I'll try to trace it. Saying that, since I wrote this thread, the car has been starting/ driving with AC on, no problem but by work of magic. Which now makes me more paranoid to drive it because I know the problem hasn't been solved. I managed to get a 2nd hand harness part the one includes the black box . I'll replace that because mine had few burned fuse traces where the HL fuses are. I'll inspect the wire diagram from anything from battery/ignition/fuel/ECU next. One more thing. I sometimes hear noise while driving from the glove where the ECU lives and bunch of other ECUs, it sounds like rebooting. It doesn't happen frequently but unfortunately while driving so haven't been able to allocate it properly. But if it's the ECU, then I don't know what the means.
inkpot
SILVER Star
Check the connector for EB1 in the first diagram, post #27. It is mounted to the intake manifold next to the power steering reservoir. My rig died with symptoms very much like yours. Tools and I tore thru everything, in a rainstorm, and he finally figured it out. The connector had corroded and there were only a few strands of wire holding the harness together. You can test this idea by running a long jumper wire from the Positive post of the battery to the B+ pin on your diagnostic socket, if you have that on your rig. John
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- #40
Great! EB1 connector is part of the harness I bought and planning to install. I have the B+ pin, in mine pin B+ is number 8. I read in other rigs its number 12. Good tip on the direct connection.
Thanks GOLD!
