Topic: o2 sensor wiring melted to exhaust and fried something

[bluetoy84]

I posted this on pirate, but I thought I would post it here too. I need this fixed tonight.

I just swapped motors in my '89 22RE. I accidentally left the wiring for the o2 sensor too loose and it got on my exhaust and melted one of the wires to the pipe. Last night I was driving up the road and it died like you turned the key off, and now won't start. I checked all the fuses and can't find any that are bad. I thought it would have blowed the 15 amp efi fuse under the hood but it was fine. It was a black wire in the o2 harness about 6" from the o2 sensor that grounded out.

I hate to even post this on here without doing a little more diagnostics, but I'm supposed to lead a club ride tommorow so I need it running tonight. Any chance it could have zapped the ECU, or is there something else I need to check?

Any help would be greatly appreciated. Thanks.

[THK Matt]

ouch... sounds like a fuse to me.

[bluetoy84 [OP]]

I hope that's all it is, but I visually checked all the fuses and swapped out the EFI fuse and it still won't start. I'm just wondering if it could have fried sometning else.

[THK Matt]

i dont think so.
check all those connectors... and replace the O2 sensor.. that o2 connection might be messed up?

[Rockcrawlintoy]

that happened to me while driving down I-5. its frying the EFI fuse. i melted all the wires what i did was clip the O2 sensor wires and drive home. you will be in limp mode but its not goin to hurt anything. i would look for more wires that got melted because there is still something shorting out

[bluetoy84 [OP]]

The problem is that the EFI fuse is not blown, but it still won't start. Any other suggestions?

[Rockcrawlintoy]

is it getting fuel and spark?

[bluetoy84 [OP]]

Haven't had a chance to check. I think it is. Happened late last night, I'm at work today.

My uncle is the manager of the Lexus dealership here in Huntsville, and he just talked to the Lexus techs for me. They said two of the wires on the o2 sensor go straight to the ECU and if one of those shorted out it could have fried the ECU.

This was my thinking all along since it didn't blow any fuses. I'll take the ECU out of my DD when I get home and see if it will run with it.

[BLACKDOG]

I did that not long ago, and it was blowing the EFI fuse on a regular basis until I figured it out.  I fixed the wire, and problem solved.  However, I was melting more than one wire, and they were shorting out against each other, rather than on the truck.  That might be the difference