Topic: HELP! trucks throwing code 12 and 51 at me.

[86turboyota]

1988 Toyota 4x4 pickup 22-re 5spd.  After the truck sat for about week while i was replacing wheel bearings and a cv joint, it started right up and i let it idle until it got up to temperature then i shut it down.  It wouldnt start again after that.  It turns over and sounds like it wants to run but it wont stay going for more than a few seconds.  I checked the diagnostic codes and it gave me a code 12 which the manuel says is RPM signal, and a code 51 which is Switch Signal.  Im not sure what to make of these codes.  I cant help but wonder if the fuel pump is the problem, because i cant here it going like i normaly can, however i replaced the fuel pump in the last year.  PLEASE HELP.
Thanks,
Andy

[CTENG in KS]

Check your AFM...I always am bumping the plug out of the sensor and that's what happens...starts but immediately sputters and dies.  Clumsy elbows, you know...

[86turboyota [OP]]

i just checked the air flow meter plug and it doesnt appear to be the problem.  any other ideas?

[CTENG in KS]

If you give it gas does it keep reving, or does it just die?
TPS maybe?  These things are difficult when you cannot see the truck, plus I have never had one of mine throw those codes. 

Help!!!!!!   

[86turboyota [OP]]

nope it wont run even if i hit the gas.  it just sputers and dies.

[86turboyota [OP]]

bump  

[guywithuglyyota]

I just had the same exact issue with my 22re. Code 12 and 14.  Well So far I changed the dist cap/rotor, plug wires and plugs since I needed to anyway. And the problem has not come back, however I have only driven the truck about 20 mi since. Initially it was on and off again. I think the distributor cap may have been the culprit.
Good luck!


ps: Its difficult to hear the fuel pump running inside the cab. I would turn the igniion to the On position, and push the Air flow meter door open (under the air cleaner) and listen for the Pump/or the relays kicking on inside the cab near the computer in the pass footwell. Its very rare for a fuel pump to go bad in these trucks.

[BUBBA]

Does it have gas in it.There is a possibility the pump went out,especially if it was replaced with just a parts store brand of pump instead of a toyota pump.Have you checked for pressure yet.Just loosen the fitting at the cold start inj. and see if your getting anything.If not the have a buddy hold the flapper in the airbox open while you check for voltage at the tank.

[dieselsmoke]

check the post "important efi information" that was discribing a problem with the wiring on the drivers side in the engine compartment, good luck

[86turboyota [OP]]

since i made my past post i managed to get the truck to start and run just fine or so it seamed... i took it for a test drive without a problem then the next morning it wouldnt start.  Then today i started and used it for a little while then it just died in my driveway.  Things that we have ruled out are fuel pump, distributor(its only 2 years old) AFM(we can hear the airbox open and close)   The truck is still throwing code 51 and is now throwing code 13 instead of 12... im wondering if its possible that the coil is the problem?  how can i check it? is that a common problem?  Please help with any sugestions.

[86turboyota [OP]]

bump

[guywithuglyyota]

since i made my past post i managed to get the truck to start and run just fine or so it seamed... i took it for a test drive without a problem then the next morning it wouldnt start.  Then today i started and used it for a little while then it just died in my driveway.  Things that we have ruled out are fuel pump, distributor(its only 2 years old) AFM(we can hear the airbox open and close)   The truck is still throwing code 51 and is now throwing code 13 instead of 12... im wondering if its possible that the coil is the problem?  how can i check it? is that a common problem?  Please help with any sugestions.

Im still havin the same exact problem you are. Im gonna swap in a new ignitor, possibly a coil that a friend has laying around as a spare. I will let ya know if it solves anything.   

[86turboyota [OP]]

btt 

[guywithuglyyota]

hey TurboYota, I changed my fuel filter two days ago and so far am having good luck. It was not the most exciting job on my 94 (bolted under intake manifold on block)
but it has not died on me so far. Im gonna take another 2 hour trip this weekend and I will let ya know if this fixes it for good. It was the cheapest, next in line part to change, and it never hurts to change it anyway.

My only worry is why would the computer throw a code for a fuel starvation problem?  Well see!

[86turboyota [OP]]

btt

[guywithuglyyota]

After my fuel filter change im still not having any more issues. Might be worth a try, annoying job on my 94 but cant hurt.

[86turboyota [OP]]

my fuel filter is less than a year old.  I think that the problems is now only occuring once the truck gets up to temperature and is there for a time. And it wont restart till the truck is somewhat cold again.  Im wondering if it could possibly be a bad O2 censor or something like that.

[86turboyota [OP]]

now im wondering if an exhaust leak that i have in front of the o2 senosor could be causing the problem?  Please HELP