Help with error codes 21 & 77

[eezynee]

Hi, I have an 87 with the 2.9, it took a shit on me a couple months back, just died as I was driving down the road and would crank but not start. I ended up replacing all kinds of parts to try and get it started and the TFI module was what finally did the trick. Throughout the process I've put in a new coil, plugs and wires, a new in tank fuel pump sending unit, new EGR valve, sensor and solenoid, new TPS, new ECT, I think a new MAP too but not sure on that one, replaced the fuel pump and ecc relays, and replaced the computer with one from the junkyard. I used to have way more codes but they've all gone away with the exception of 21 & 77, for the ECT sensor and the TPS, which I've replaced with new parts twice. The truck starts right up every single time and idles smoothly, but has a weird throttle issue where it almost won't let me go past 2000 rpms, and if I floor it it will eventually fight through until it's smooth again at 5000 rpms, but between 2000-5000 rpms it jumps around like crazy, and the exhaust is pretty white. I'm not much of a mechanic but I can usually figure some stuff out if I find an example online of someone experiencing the same issues and they found the solution. It's entirely possible I messed something up while putting in the new fuel pump or any of the other little projects I've done.

Any ideas?

 

[franklin2]

Did you keep all your old parts? It's very common to install bad new parts. Here's a video to prove it. If you don't want to watch the whole thing, you can start at around 38:00 and see what he finally found out. A bunch of parts had been replaced on this truck also.

 

[franklin2]

By the way, the most common reason a code 21 is received is not letting the engine warm up fully before pulling the codes. A cold engine will give you a code 21. The most common reason a code 77 is received is because you did not perform the goose test when it asked you to. So you may not have any problems at all if you do the testing properly. If you want to try again, make sure you disconnect the battery for a minute or so to erase the old codes.

 

[eezynee]

At which point in the keor test am I supposed to give it throttle for the goose test?

 

[eezynee]

By the way, the most common reason a code 21 is received is not letting the engine warm up fully before pulling the codes. A cold engine will give you a code 21. The most common reason a code 77 is received is because you did not perform the goose test when it asked you to. So you may not have any problems at all if you do the testing properly. If you want to try again, make sure you disconnect the battery for a minute or so to erase the old codes.

Here’s a video of the weird throttling

http://imgur.com/a/c0OlRgZ

 

[franklin2]

At which point in the keor test am I supposed to give it throttle for the goose test?

Get the engine warmed up. Turn it off and then set it up to retrieve the codes. Then start the engine.

1st thing you will see is the engine ID codes. You have a six cylinder, so you should see 3 blinks or blips depending on how you are reading the codes.


After that you may hear clicking and the engine speed may vary as the computer is testing things.

Then the engine will smooth out. Then you will get one beep, blink or blip from the meter needle, this is your sign to press the accelerator to the floor and rev the engine and then let it back down to idle. You have 10 seconds to do this. This is the goose test.

Then you may see a partial blip, this is the factory fast codes. And then you will receive the KOER codes like you did before. Hopefully you get an 11.

 

[franklin2]

Here’s a video of the weird throttling

http://imgur.com/a/c0OlRgZ

To me that looks like a loose wire in the ignition part of the engine. The tach is driven directly off the signals to fire the ignition coil. See the tach go crazy like that is a hint to me you are losing that coil firing signal somewhere. I would check the wiring around the coil and trace it back to the module on the side of the distributor. The wiring leaving the distributor has a tin foil shield around it. This tin foil shield has been known to get where it doesn't belong and short the wiring out to the distributor. I would check that also.

 

[Paulos]

I've attached a PDF of the Innova code reader, and it explains the code retrieval processes in detail, including the KOER SELF TEST. I personally wouldn't trust a junkyard ECM. That may be why the vehicle is there.
And if you're just pulling codes, it's not necessary to run a KOER SELF TEST (which requires starting the engine). Just plug in your code reader and turn the igniton on.

 

[franklin2]

The engine ID part of the KOER is handy to make sure you at least have the right computer in it. Things happen through the years, you never know. It will also alert you if the throttle body is all messed up and out of adjustment.

 

[franklin2]

I was also thinking more about your cutting out problem. If you still have that, pull the spout connector and see if that problem goes away. If it does, that says you have a problem with the spout wire, or a problem with the computer and its' not giving consistent timing info to the distributor. Taking the spout connector out will lock the timing to the base setting.

 

[eezynee]

I was also thinking more about your cutting out problem. If you still have that, pull the spout connector and see if that problem goes away. If it does, that says you have a problem with the spout wire, or a problem with the computer and its' not giving consistent timing info to the distributor. Taking the spout connector out will lock the timing to the base setting.

I tried taking out the spout connector and that didn't help with the cutting out issue. Got a 41 code so I'm gonna see if a new oxygen sensor makes a difference.

 

[dirtymike]

O2 sensor will not cure a miss in the engine. It sends info to the ECM for the correct fuel mixture.

 

[dirtymike]

Code 21 is for the ECT. I have installed one with the wrong calibration and it made the engine idle higher than normal. Code 77 is a operator error. The goose test was done insufficiently. Dirty