Hello

1992 f250 351 4x4 Only getting .1 volts at the iac. when I turn on the
ignition to run. Guess I need a computer? It gets to like 5 volts when its running

replaced all the sensors . Anybody know what the manifold vacumn should be
at idle. I am getting a steady 11 inch lbs at idle?

She runs out like 90 percent when its waemed up

Is this a mistake? My truck came with super duty cooling it said on the sticker.
My clutch fan started to squeel so I went to pep boys and they gave me a severe duty one. It was alot more heavy duty then the one that was on there.
I put it on there and it roars till it gets warmed up.

 

A lot more then that, should be 17-21 inches.

 

I traced the white wire with the blue tracer to where it comes out of the computer.
put the positive on the battery and the neg on the computer wire and am getting
.o1 volts. in the run position.I guess when engine is running it changes values and sends more voltage. I changed the coolant temp. twice. The new was just a little low on ohms when I changed it so I changed it again? Manafold vacumn is low? Maybe timing.
Maybe computer is messing up the timing. I didnt do a compression test but it burns like no oil.154000 miles Run local with like 700 lbs in the bed she will burn 1 quart every 2000
miles

 

I checked the vacumn where it when in the egr soilnoid and it was 11 but I just checked it coming from the manifold and it was a marveloso 16 lbs. Nice and steady!!!!!

 

To start with that is a variable grounded wire by the computer and not a power wire. The IAC valve gets 12 volts ~ from the PCM Power relay (361 red wire) and the computer variably grounds the other side of the coil.

 

The varible ground on the iac is blue and white and I traced backed to the fire wall before it goes in the computer. and tested there to make sure it wasnt a faulty wire, In my book they
show the positive side of the iac jumping off the fuel injectors. But I am
still only getting .01 volts at the Iac?

 

the book says it should be 10.5 volts at the iac in the run position?

 

You got a lot of fords. Kansas. Follow the yellow brick road. Tornadoes been down this year?

 

Sounds like the book is wrong.
What book are you reading?

The red wire should have battery voltage on it and the other wire varies from zero volts ~ to battery voltage depending on the what the computer thinks is right to maintain the RPM it wants.

 

I get a cracklin cold 12.8 volts from the red @ iac to frame ground

 

it idles smooth but total bogs when its not warmed up and a flat spot.

 

wheres the knock sensor located?

 

Could be the TPS. You need to check to see what codes you have in KOEO & CM.

 

A simple test to find out if the IAC is working, is to unplug the IAC solenoid and see how the engine's idle is affected. Most times the engine's idle will drop to the "curb idle" or may even stall out.

What codes are you getting from the ECU?

 

You do not have one.