Ok I need some help from the toyota gods that lurk yotatech. I hydrolocked my 3.0 in my 89' pickup a few months back. So I went out and bought a 1992 4runner 3.0, 89,xxx on it. Got the new motor all in with the old harness and I run a code 51 .Engine idles good but when it warms it stalls but will start up and run fine right after.When I give it gas it will studer at low rpm and it is running really rich. So thinking I would remedy the problem with that and a few other codes I put the old intake plenum on. Re-tuned the tps (new for the 89 plenum) and still the code 51. Short of swapping in the 92' ecu as I believe they are diferen't am I missing something? The code 51 is a/c amplifier, a/c circuit, tps circuit. I really don't want to have to put the 92 harness and ecu in and change plenum's again. Any way that this can be fixed short of doing the above?

 

Any one, this code 51 is driving me nuts!

 

Get a new TPS I guess. Or fix the one you have.

Ya see...

I had the same code for the first year or so I owned my truck. Finally got around to fixing it and it didn't make much difference(if any)in how it ran. Just got rid of the code. It sure never caused me the problem you've described, and I'm not sure if/how it possibly could. That's a bit puzzling....because from what I've gathered you can unplug the TPS and the engine will run alright without it. Never tried that myself though.

So anyway, how'd I solve it?

I tore the TPS apart and cleaned 'er out real good. It was all gummed up inside and wouldn't shut all the way at idle. So all my attempts at adjusting it to specs were a total waste of time. Anywho, she works good as new now!

Might try doin' like me, if you haven't lost all your patience with the damn thing yet.

 

Well it idles great now that i have replaced almost everything! It's just when I give it a little bit of gas it stumbles. I know the motor sat for a while before I put it in so I am just going to run it for a bit and try to clean it out. After that I am kinda out of ideas. I will keep everyone posted.

 

Put in a new tps and still the same code 51. The motor idles great but when you give it that little bit f gas it stumbles and then the code pops up. My truck never came with a/c and I am using the old harness and all the sensors that came with my year motor and ecu. The new motor is a 92 that had a/c. Am I missing something? I can't even drive the truck it sucks, I have a fresh sas and can not drive it. Any other sugestions anyone????????? I am out of ideas I have replaced cap,wires,plugs,fuel filter, ran injector cleaner, seafoam,new tps, new knock sensor and wire, it is grounded at the ecu. I have tested all sensors and wiring and it's within fsm specs.

 

Ok so I think I may have found something else that may be causing an issue. I unplugged the tps sensor tonight and found that the only difference is the idle it is very rough. I t still has the hesitation and lack of power. So I investigated the wires for the distributor. I found that inside the plug the plastic dividers were broken resulting in the connectors possibly arcing or mixing signals? Is this possible?

 

51 is a 'switch signal' and means that either the TPS isn't adjusted properly (IDL - E2 contacts), clutch switch is on, or a/c is on.
Clear the code by removing the EFI fuse or disconnecting the battery for a minute or two, make sure the a/c is off, start the truck then insert the jumper with the engine running and see what codes you get. Don't worry about putting the jumper in with the engine running, the codes will repeat indefinitely, until you remove the jumper.

 

abecedarian, I do not have a/c in my truck, I have tested the tps and reset the tps per 4crawlers specs and I am still getting the code,after resetting the ecm. You did mention the clutch switch? Are you talking about the sensor at the pedal or the actual clutch start cancel button on the dash? I will check both tonight when I get home from work. Thanks.

 

Are you sure you donot have any cracks in the main intake hose before the tps and after air flow meter? Throttle body vac leaks? Where did you get the tps from? If you got it from a parts store new it has to be adjust accordingly or it will not work properly. If you bought it from toyota it comes pre adjusted. if you got it used....hehe well good luck. any time you do a job to fix or replace something causing a trouble code you disconnet the battery and do your repair job then after job reset computer then fire it up.

 

Excuse me but there's no way the TPS can be pre-adjusted from Toyota....two set screws hold it in place & you have to adjust it when you install it.

 

Well as we all know the tps does NOT come preadjusted, and resetting the ecu is standard on most sensor installs. I have replaced the afm and it still runs the same. Thinking it has to be in the wiring on the tps , I checked the connection at the ecu it checked ok. Does anyone have a pinout for the ecm for an 89 pickup 3.0?

 

On the second page...
http://personal.utulsa.edu/~nathan-b...86troubles.pdf

 

You said you had broken pieces in the distributor; did you replace the distributor yet??

 

How is the Tps not pre adjusted from toyota? Maybe i was told wrong... the man at the counter in the parts department told me so... I asked him if the tps had to be adjusted or did it come pre adjusted...(was told by a friend of mine they were..) and the man behind the counter looked at the computer and said yup its pre adjusted.... i said ok. am i wrong maybe so..... anywho i'm leaning toward distributor since you said broken parts in it too....

 

Yes I put a new distributor from a 92, the same as my new motor,same results. I have never heard of a tps sensor being self adjusting on a toyota. I know on the heeps they have no adjustment. Thnaks for the pinout!Going to see what I can come up with tomorow.

 

It sounds to me like a faulty temp reading the ECU may be getting from somewhere. Possible air temp sensor inside the mass air flow itself is fualty and or dirty. When the engine is running bad have you tried beating on the mass air flow or unplugging it for any change? Coolant temp sensor faulty? hows your EGR is it working properly. Opening at the wrong times and or too early? unplugg it and see if theres any change.... dunno what to tell you about your code unless you try other tps from another vehicle or another new one... wire may have opens or breaks going to the connector...

 

u hydrolocked... was the ecu wet too?

 

Nope the ecu was fine I had previously moved it up behind the glovebox. I installed a new afm over the weekend, no change. I am going to see if there are any breaks in the wiring at the tps sensor itself. Cooler temp sensor, now if bad or having a faulty reading could that cause such a malfunction like this?

 

yes sir but it seems to lead more toward the tps in your case.

 

From what I can tell it has to be the tps wiring and or a faulty tps sensor but it tests out fine and adjusts to specs within reason. We will see what tonight brings!