code 25 93 4runner
11-19-2016, 05:48 AM
#1
Registered User
Thread Starter
Join Date: Nov 2016
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
code 25 93 4runner
New guy on the site. I'm trying to diagnose a no start issue. Searched a bunch of threads and cant quite find a similar issue. Any help[ would be greatly appreciated.
Picked up a 93 4runner a couple months ago. Previous owner said it ran a little rough. I replaced plugs, distributor rotor, fuel filter and air filter. Still runs a little rough. Here's the issue that has me stumped. I can go out in the morning and start it, drive it some where, i.e. supermarket, come back to the vehicle and it won't start. I can wait about 20 min. or so, try again, and it will start. Pulled code 25 this morning "mixture control continuously lean". Not sure where to go from here.
Thanks in advance for your help.
Shawn
Picked up a 93 4runner a couple months ago. Previous owner said it ran a little rough. I replaced plugs, distributor rotor, fuel filter and air filter. Still runs a little rough. Here's the issue that has me stumped. I can go out in the morning and start it, drive it some where, i.e. supermarket, come back to the vehicle and it won't start. I can wait about 20 min. or so, try again, and it will start. Pulled code 25 this morning "mixture control continuously lean". Not sure where to go from here.
Thanks in advance for your help.
Shawn
11-19-2016, 06:16 AM
#2
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,252
Likes: 0
Received 820 Likes
on
648 Posts
Code 25 is a stored code, so it may help to occasionally reset it by removing the EFI fuse for 30 seconds (you can disconnect the battery, but then you lose the radio presets, the learned fuel trim, the clock, ...)
"run a little rough" and code 25 point to a vacuum leak. Look carefully at the induction plumbing from the air cleaner to throttle body, and make sure all the small vacuum hoses go somewhere (you didn't say which engine you have, but the advice is the same). Many have success using an unlit propane torch; the idle will rise when closer to the vacuum leak.
There is a fuel pressure-up system to counter-act vapor lock, and a problem with that system could lead to problems with hot starts. But if you have a code, I'd start there first.
"run a little rough" and code 25 point to a vacuum leak. Look carefully at the induction plumbing from the air cleaner to throttle body, and make sure all the small vacuum hoses go somewhere (you didn't say which engine you have, but the advice is the same). Many have success using an unlit propane torch; the idle will rise when closer to the vacuum leak.
There is a fuel pressure-up system to counter-act vapor lock, and a problem with that system could lead to problems with hot starts. But if you have a code, I'd start there first.
11-20-2016, 08:33 AM
#3
Registered User
Thread Starter
Join Date: Nov 2016
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
I had pulled the efi previously, so this is the first code to come up. One of the possible causes listed with this code was "H02S" heated oxygen sensor. I put a meter to it and it tested at 12.4 ohms. Outside the parameters. While trying to replace it, the remaining mounting bolt sheared. One was already broken. Now I have to figure out how to remove the exhaust pipe (more rusted bolts) and install the new 02 sensor. I'm thinking new pipe.
